Qt5——主窗口-阿里云开发者社区

文章目录

Qt5 主窗口构成

基本元素

示例：文本编辑器

示例步骤及代码

显示结果

Qt5 文件操作功能

新建文件

打开文件

打印文件

Qt5 图像坐标变换

缩放功能

旋转功能

Qt5 文本编辑功能

实现文本编辑的具体步骤：

Qt5 排版功能

最终实现效果及全部代码

全部代码

界面效果

Qt5 主窗口构成

基本元素

QMainWindow是一个为用户提供主窗口程序的类，包含一个菜单栏（menu bar）、多个工具栏（tool bars）、多个锚接部件（dock widgets）及一个中心部件（central widget），是许多应用程序的基础，如文本编辑器、图片编辑器等。

接下来将详细介绍关于这些的基本元素

菜单栏
菜单是一系列命令的列表。为了实现菜单、工具栏按钮、键盘快捷方式等命令的一致性，Qt使用动作（Action）来表示这些命令。Qt的菜单就是由一系列的QAction动作对象构成的列表，而菜单栏则是包容菜单的面板，它位于主窗口顶部、主窗口标题栏的下面。一个主窗口最多只有一个菜单栏。
状态栏
状态栏通常显示GUI应用程序的一些状态信息，它位于主窗口的底部。用户可以在状态栏上添加、使用Qt窗口部件。一个主窗口最多只能有一个状态栏。
工具栏
工具栏是由一系列的类似于按钮的动作排列而成的面板，它通常由一些经常使用的命令（动作）组成。工具栏位于菜单栏的下面、状态栏的上面，可以停靠在主窗口的上、下、左、右四个方向上。一个主窗口可以包含多个工具栏。
锚接部件
锚接部件作为一个容器使用，以包容其他窗口部件来实现某些功能。例如：Qt设计器的属性编辑器、对象监视器等都是由锚接部件包容其他的Qt窗口部件来实现的。它位于工具栏区的内部，可以作为一个窗口自由浮动在主窗口上面，也可以像工具栏一样停靠在主窗口的上、下、左、右四个方向上。一个主窗口可以包含多个锚接部件。
中心部件
中心部件处于锚接部件区的内部、主窗口的中心。一个主窗口只有一个中心部件。

注：主窗口QMainWindow具有自己的布局管理器，因此在QMainWindow窗口上设置布局管理器或者创建一个父窗口部件作为QMainWindow的布局管理器都是不允许的。但可以在主窗口的中心部件上设置管理器。

示例：文本编辑器

接下来通过完成一个文本编辑器应用实例，来介绍关于QMainWindow主窗体的创建流程核各种功能的开发。

首先，极少文件操作功能，包括新建一个文件，理由标准文件对话框QFileDialog类打开一个已存在的文件，利用QFile和QTextStream读取文件内容，打印文件（分文本打印和图像打印）。通过示例介绍标准打印对话框QPrintDialog类的使用方法，以QPrinter作为QPaintDevice画图实现图像打印。

接着，介绍图像处理软件中的常用功能，包括图片的缩放、旋转及镜像等坐标变换，使用QMatrix实现图像的各种坐标变换。

然后，开发文本编辑功能，通过在工具栏上设置文字字体、字号大小、加粗、斜体、下划线及字体颜色等快捷按钮的实现，介绍了在工具栏中嵌入控件的方法。其中，通过设置字体颜色功能，介绍了标准颜色对话框QColorDialog类的使用方法。

最后是排版功能，通过选择某种排序方式实现对文本排序，以及实现文本对齐（包括左对齐、右对齐、居中对齐和两端对齐）和撤销、重做的方法。

示例步骤及代码

首先简历项目的框架代码：

新建Qt Widgets Application项目，项目名称为“ImageProcessor”，基类选择“QMainWindow”，类名命名为“ImgProcessor”，取消“创建界面”复选框的选中状态。完成项目工程的建立。
添加工程的提供主要显示文本编辑框函数所在的文件，点击右键添加新文件，选择“C++Class”选项，选择基类名“QWidget”，类命名为“ShowWidget”，在源文件和头文件添加以下代码：
showwidget.h

#ifndef SHOWWIDGET_H
#define SHOWWIDGET_H
#include 
#include 
#include 
#include 
class ShowWidget : public QWidget
{
    Q_OBJECT
public:
    explicit ShowWidget(QWidget *parent = nullptr);
    QImage img;
    QLabel *imageLabel;
    QTextEdit *text;
signals:
public slots:
};
#endif // SHOWWIDGET_H

showwidget.cpp

#include "showwidget.h"
#include
ShowWidget::ShowWidget(QWidget *parent) : QWidget(parent)
{
    imageLabel = new QLabel;
    imageLabel->setScaledContents(true);
    text = new QTextEdit;
    QHBoxLayout *mainLayout = new QHBoxLayout(this);
    mainLayout->addWidget(imageLabel);
    mainLayout->addWidget(text);
}

主函数 ImgProcessor 类声明中，createActions() 函数用于创建所有的动作，createMenus() 函数用于创建菜单、createToolBars() 函数用于创建工具栏；接着声明实现主窗口所需的各个元素，包括菜单、工具栏及各个动作等；最后声明用到的槽函数，打开“imgprocessor.h”文件，添加以下代码：

#ifndef IMGPROCESSOR_H
#define IMGPROCESSOR_H
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include "showwidget.h"
class ImgProcessor : public QMainWindow
{
    Q_OBJECT
public:
    ImgProcessor(QWidget *parent = nullptr);
    ~ImgProcessor();
    void createActions();
    void createMenus();
    void createToolBars();
    void loadFile(QString filename);
    void mergeFormat(QTextCharFormat);
private:
    QMenu *fileMenu;
    QMenu *zoomMenu;
    QMenu *rotateMenu;
    QMenu *mirrorMenu;
    QImage img;
    QString fileName;
    ShowWidget *showWidget; //文件菜单项
    QAction *openFileAction;
    QAction *NewFileAction;
    QAction *printTRextAction;
    QAction *printImageAction;
    QAction *exitAction;
    QAction *copyAction;    //编辑菜单项
    QAction *cutAction;
    QAction *pasteAction;
    QAction *aboutAction;
    QAction *zoomInAction;
    QAction *zoomOutAction;
    QAction *rotate90Action;    //旋转菜单项
    QAction *rotate180Action;
    QAction *rotate270Action;
    QAction *mirrorVerticalAction;  //镜像菜单项
    QAction *mirrorHorizontalAction;
    QAction *undoAction;
    QAction *redoAction;
    QToolBar *fileTool; //工具栏
    QToolBar *zoomTool;
    QToolBar *rotateTool;
    QToolBar *mirrorTool;
    QToolBar *doToolBar;
};
#endif // IMGPROCESSOR_H

下面是主窗口的部分代码：

#include "imgprocessor.h"
ImgProcessor::ImgProcessor(QWidget *parent)
    : QMainWindow(parent)
{
    setWindowTitle(tr("Easy Word"));    //窗口标题
    showWidget = new ShowWidget(this);
    setCentralWidget(showWidget);
    //创建动作、菜单、工具栏
    createActions();
    createMenus();
    createToolBars();
    if(img.load("mage.png"))
    {
        //在imagelabel中放置图像
        showWidget->imageLabel->setPixmap(QPixmap::fromImage(img));
    }
}
ImgProcessor::~ImgProcessor()
{
}
void ImgProcessor::createActions()
{
    //“打开”动作
    openFileAction = new QAction(QIcon("open.png"), tr("打开"), this);
    openFileAction->setShortcut(tr("Ctrl+O"));  //设置此动作的组合键
    openFileAction->setStatusTip(tr("打开一个文件"));//设定状态栏显示。
    //“新建”动作
    NewFileAction = new QAction(QIcon("new.png"), tr("新建"), this);
    NewFileAction->setShortcut(tr("Ctrl+N"));
    NewFileAction->setStatusTip(tr("新建一个文件"));
    //“退出”动作
    exitAction = new QAction(tr("退出"), this);
    exitAction->setShortcut(tr("Ctrl+Q"));
    exitAction->setStatusTip(tr("退出程序"));
    connect(exitAction, SIGNAL(triggered()), this, SLOT(close()));
    //“复制”动作
    copyAction = new QAction(QIcon("copy.png"), tr("复制"), this);
    copyAction->setShortcut(tr("Ctrl+C"));
    copyAction->setStatusTip(tr("复制文件"));
    connect(copyAction, SIGNAL(triggered()), showWidget->text, SLOT(copy()));
    //“剪切”动作
    cutAction = new QAction(QIcon("cut.png"), tr("剪切"), this);
    cutAction->setShortcut(tr("Ctrl+X"));
    cutAction->setStatusTip(tr("剪切文件"));
    connect(cutAction, SIGNAL(truggered()), showWidget->text, SLOT(cut()));
    //“粘贴”动作
    pasteAction = new QAction(QIcon("paste.png"), tr("粘贴"), this);
    pasteAction->setShortcut(tr("Ctrl+V"));
    pasteAction->setStatusTip(tr("粘贴文件"));
    connect(pasteAction, SIGNAL(triggered()), showWidget->text, SLOT(paste()));
    //“关于”动作
    aboutAction = new QAction(tr("关于"), this);
    connect(aboutAction, SIGNAL(triggered()), this, SLOT(QApplication::aboutQt()));
    //“打印文本”动作
    printTRextAction = new QAction(QIcon("printText.png"), tr("打印文本"), this);
    printTRextAction->setStatusTip(tr("打印一个文本"));
    //“打印图像”动作
    printImageAction = new QAction(QIcon("printImage.png"), tr("打印图像"), this);
    printImageAction->setStatusTip(tr("打印一幅图像"));
    //“放大”动作
    zoomInAction = new QAction(QIcon("zoomin.png"), tr("放大"), this);
    zoomInAction->setStatusTip(tr("放大一张照片"));
    //“缩小”动作
    zoomOutAction = new QAction(QIcon("zoomout.png"), tr("缩小"), this);
    zoomOutAction->setStatusTip(tr("缩小一张照片"));
    //实现图像旋转的动作
    //90
    rotate90Action = new QAction(QIcon("rotate90.png"), tr("旋转90"), this);
    rotate90Action->setStatusTip(tr("将一幅图像旋转90度"));
    //180
    rotate180Action = new QAction(QIcon("rotate180.png"), tr("旋转180"), this);
    rotate180Action->setStatusTip(tr("将一幅图像旋转180度"));
    //270
    rotate270Action = new QAction(QIcon("rotate270.png"), tr("旋转270"), this);
    rotate270Action->setStatusTip(tr("将一副图像旋转270度"));
    //实现图像镜像的动作
    //纵向
    mirrorVerticalAction = new QAction(QIcon("mirrorV.png"), tr("纵向镜像"), this);
    mirrorVerticalAction->setStatusTip(tr("对一幅图像纵向镜像"));
    //横向
    mirrorHorizontalAction = new QAction(QIcon("mirrorH.png"), tr("横向镜像"), this);
    mirrorHorizontalAction->setStatusTip(tr("对一副图像横向镜像"));
    //实现撤销和恢复动作
    undoAction = new QAction(QIcon("undo.png"), tr("撤销"), this);
    connect(undoAction, SIGNAL(triggered()), showWidget->text, SLOT(undo()));
    redoAction = new QAction(QIcon("redo.png"), tr("重做"), this);
    connect(redoAction, SIGNAL(triggered()), showWidget->text, SLOT(redo()));
}
void ImgProcessor::createMenus()
{
    //文件菜单
    fileMenu = menuBar()->addMenu(tr("文件"));  //menuBar()得到主窗口的菜单栏指针，调用函数addMenu()插入一个新的菜单。
    fileMenu->addAction(openFileAction);//调用addAction()函数向菜单中加入菜单条目
    fileMenu->addAction(NewFileAction);
    fileMenu->addAction(printTRextAction);
    fileMenu->addAction(printImageAction);
    fileMenu->addSeparator();//插入空格
    fileMenu->addAction(exitAction);
    //缩放菜单
    zoomMenu = menuBar()->addMenu(tr("编辑"));
    zoomMenu->addAction(copyAction);
    zoomMenu->addAction(cutAction);
    zoomMenu->addAction(pasteAction);
    zoomMenu->addAction(aboutAction);
    zoomMenu->addSeparator();
    zoomMenu->addAction(zoomInAction);
    zoomMenu->addAction(zoomOutAction);
    //旋转菜单
    rotateMenu = menuBar()->addMenu(tr("旋转"));
    rotateMenu->addAction(rotate90Action);
    rotateMenu->addAction(rotate180Action);
    rotateMenu->addAction(rotate270Action);
    //镜像菜单
    mirrorMenu = menuBar()->addMenu(tr("镜像"));
    mirrorMenu->addAction(mirrorVerticalAction);
    mirrorMenu->addAction(mirrorHorizontalAction);
}
void ImgProcessor::createToolBars()
{
    //文件工具条
    fileTool = addToolBar("File");  //QMainWindow直接调用addToolBar()函数获得主窗口的工具条对象。
    fileTool->addAction(openFileAction);//向工具条查出属于该工具条的工作。
    fileTool->addAction(NewFileAction);
    fileTool->addAction(printTRextAction);
    fileTool->addAction(printImageAction);
    //编辑工具条
    zoomTool = addToolBar("Edit");
    zoomTool->addAction(copyAction);
    zoomTool->addAction(cutAction);
    zoomTool->addAction(pasteAction);
    zoomTool->addSeparator();
    zoomTool->addAction(zoomInAction);
    zoomTool->addAction(zoomOutAction);
    //旋转工具条
    rotateTool = addToolBar("rotate");
    rotateTool->addAction(rotate90Action);
    rotateTool->addAction(rotate180Action);
    rotateTool->addAction(rotate270Action);
    //撤销和重做工具条
    doToolBar = addToolBar("doEdit");
    doToolBar->addAction(undoAction);
    doToolBar->addAction(redoAction);
}

显示结果

Qt5 文件操作功能

新建文件

实现新建空白文件的功能，步骤如下：

打开“imgprocessor.h”头文件，添加槽函数及实现如下：

private slots:
    void showNewFile();//新建文件

void ImgProcessor::createActions()
{
    //“新建”动作
    NewFileAction = new QAction(QIcon("new.png"), tr("新建"), this);
    NewFileAction->setShortcut(tr("Ctrl+N"));
    NewFileAction->setStatusTip(tr("新建一个文件"));
    connect(NewFileAction, SIGNAL(triggered()), this, SLOT(showNewFile()));
}
void ImgProcessor::showNewFile()
{
    ImgProcessor *newImgProcessor = new ImgProcessor;
    newImgProcessor->show();
}

打开文件

打开功能是读取一个已经存在的文件，将文件内容显示在窗口中。

在头文件和源文件中添加对应的槽函数及实现：

void showOpenFile();//打开文件

void ImgProcessor::createActions()
{
    //“打开”动作
    openFileAction = new QAction(QIcon("open.png"), tr("打开"), this);
    openFileAction->setShortcut(tr("Ctrl+O"));
    openFileAction->setStatusTip(tr("打开一个文件"));
    connect(openFileAction, SIGNAL(triggered()), this, SLOT(showOpenFile()));
｝
void ImgProcessor::loadFile(QString filename)
{
    qDebug() << "file name :" << filename;
    QFile file(filename);
    if(file.open(QIODevice::ReadOnly | QIODevice::Text))
    {
        QTextStream textStream(&file);
        while(!textStream.atEnd())
        {
            showWidget->text->append(textStream.readLine());
            qDebug() << "read line";
        }
    }
}
void ImgProcessor::showOpenFile()
{
    fileName = QFileDialog::getOpenFileName(this);
    if(!fileName.isEmpty())
    {
        if(showWidget->text->document()->isEmpty())
        {
            loadFile(fileName);
        }
        else
        {
            ImgProcessor *newImgProcessor = new ImgProcessor;
            newImgProcessor->show();
            newImgProcessor->loadFile(fileName);
        }
    }
}

打印文件

打印的文件分为文本和图片两种格式，下面分别介绍。

文本打印

使用Qt提供的标准打印对话框，QPrintDialog。具体如下：

void showPrintText();//打印文本文件

connect(printTRextAction, SIGNAL(triggered()), this, SLOT(showPrintText()));
void ImgProcessor::showPrintText()
{
    QPrinter printer;
    QPrintDialog printDialog(&printer, this);//创建一个QPrintDialog对象。
    if(printDialog.exec())
    {
        //获得QTextEdit 对象的文档
        QTextDocument *doc = showWidget->text->document();
        doc->print(&printer);
    }
}

图像打印

添加槽函数。

void showPrintImage();//打印图片

connect(printImageAction, SIGNAL(triggered()), this, SLOT(showPrintImage()));
void ImgProcessor::showPrintImage()
{
    QPrinter printer;
    QPrintDialog printDialog(&printer, this);
    if(printDialog.exec())
    {
        QPainter painter(&printer);
        QRect rect = painter.viewport();//获得QPainter 对象的视图矩形区域
        QSize size = img.size();
        //安装图片的比例大小重新设定视图矩形区域
        size.scale(rect.size(), Qt::KeepAspectRatio);
        painter.setViewport(rect.x(), rect.y(), size.width(), size.height());
        painter.setWindow(img.rect());
        painter.drawImage(0, 0, img);
    }
}

Qt5 图像坐标变换

QMatrix类提供了世界坐标系统的二维转换功能，可以使窗体转换变形，经常在绘图程序中使用，还可以实现坐标系统的移动、缩放、变形及旋转功能。

setScaledContents 用来设置该控件的scaledContents属性，确定是否根据其大小自动调节内容大小，以便内容充满整个有效区域。若设置值为true，则当现实图片时，控件会根据其大小对图片进行调节。该属性默认值为false，另外，可以通过hasScaledContents() 来获取该属性的值。

缩放功能

下面将实现缩放功能。

void showZoomIn();//放大
    void showZoomOut();//缩小
void ImgProcessor::showZoomIn()
{
    if(img.isNull())//有效判断
    {
        return;
    }
    QMatrix martix;//声明一个QMatrix类的实例
    martix.scale(2, 2); //该参数决定x方向和y方向的缩放比例
    img = img.transformed(martix);
    showWidget->imageLabel->setPixmap(QPixmap::fromImage(img));
}
void ImgProcessor::showZoomOut()
{
    if(img.isNull())
    {
        return ;
    }
    QMatrix matrix;
    matrix.scale(0.5, 0.5);
    img = img.transformed(matrix);
    showWidget->imageLabel->setPixmap(QPixmap::fromImage(img));
}

旋转功能

void showRotate90(); //旋转90
    void showRotate180();
    void showRotate270();
    //实现图像旋转的动作
    //90
    rotate90Action = new QAction(QIcon("rotate90.png"), tr("旋转90"), this);
    rotate90Action->setStatusTip(tr("将一幅图像旋转90度"));
    connect(rotate90Action, SIGNAL(triggered()), this, SLOT(showRotate90()));
    //180
    rotate180Action = new QAction(QIcon("rotate180.png"), tr("旋转180"), this);
    rotate180Action->setStatusTip(tr("将一幅图像旋转180度"));
    connect(rotate180Action, SIGNAL(triggered()), this, SLOT(showRotate180()));
    //270
    rotate270Action = new QAction(QIcon("rotate270.png"), tr("旋转270"), this);
    rotate270Action->setStatusTip(tr("将一副图像旋转270度"));
    connect(rotate270Action, SIGNAL(triggered()), this, SLOT(showRotate270()));
void ImgProcessor::showRotate90()
{
    if(img.isNull())
    {
        return ;
    }
    QMatrix matrix;
    matrix.rotate(90);
    img = img.transformed(matrix);
    showWidget->imageLabel->setPixmap(QPixmap::fromImage(img));
}
void ImgProcessor::showRotate180()
{
    if(img.isNull())
    {
        return ;
    }
    QMatrix matrix;
    matrix.rotate(180);
    img = img.transformed(matrix);
    showWidget->imageLabel->setPixmap(QPixmap::fromImage(img));
}
void ImgProcessor::showRotate270()
{
    if(img.isNull())
    {
        return ;
    }
    QMatrix matrix;
    matrix.rotate(270);
    img = img.transformed(matrix);
    showWidget->imageLabel->setPixmap(QPixmap::fromImage(img));
}

Qt5 文本编辑功能

在编写包含格式设置的文本编辑程序时，经常用到的Qt类有QTextEdit、QTextDocument、QTextBlock、QTextList、QTextFrame、QTextTable、QTextCharFormat、QTextBlockFormat、QTextListFormat、QTextFrameFormat和QTextTableFormat等。

任何一个文本编辑的程序都要用到QTextEdit作为输入文本的容器，在它里面输入可编辑文本由QTextDocument作为载体，而用来表示QTextDocument的元素的QTextBlock、QTextList、QTextFrame等都是QTextDocument的不同表现形式，可以表示为字符串、段落、列表、表格或图片等。

每种元素都有自己的个数，这些格式则是用这些类来实现的。

实现文本编辑的具体步骤：

在“imgprocessor.h”头文件中添加“private”变量：

QLabel *fontLabel;
    QFontComboBox *fontComboBox;
    QLabel *fontLabel2;
    QComboBox *sizeComboBox;
    QToolButton *boldBtn;
    QToolButton *italicBtn;
    QToolButton *underlineBtn;
    QToolButton *colorBtn;
    QToolBar *fontToolBar;

在“imgprocessor.h”头文件中添加槽函数：

protected slots:
    void ShowFontComboBox(QString comboStr);
    void ShowSizeSpinBox(QString spinValue);
    void ShowBoldBtn();
    void ShowItalicBtn();
    void ShowUnderlineBtn();
    void ShowColorBtn();
    void ShowCurrentFormatChanged(const QTextCharFormat &fmt);

在相对应的构造函数中，添加以下语句：

ImgProcessor::ImgProcessor(QWidget *parent)
    : QMainWindow(parent)
{
    setWindowTitle(tr("Easy Word"));    //窗口标题
    showWidget = new ShowWidget(this);
    setCentralWidget(showWidget);
    //在工具栏上嵌入控件
    //设置字体
    fontLabel = new QLabel(tr("字体:"));
    fontComboBox = new QFontComboBox;
    fontComboBox->setFontFilters(QFontComboBox::ScalableFonts);
    fontLabel2 = new QLabel(tr("字号:"));
    sizeComboBox = new QComboBox;
    QFontDatabase db;
    foreach(int size, db.standardSizes())
        sizeComboBox->addItem(QString::number(size));
    boldBtn = new QToolButton;
    boldBtn->setIcon(QIcon("bold.png"));
    boldBtn->setCheckable(true);
    italicBtn = new QToolButton;
    italicBtn->setIcon(QIcon("italic.png"));
    italicBtn->setCheckable(true);
    underlineBtn = new QToolButton;
    underlineBtn->setIcon(QIcon("under.png"));
    underlineBtn->setCheckable(true);
    colorBtn = new QToolButton;
    colorBtn->setIcon(QIcon("color.png"));
    colorBtn->setCheckable(true);
    //创建动作、菜单、工具栏
    createActions();
    createMenus();
    createToolBars();
    if(img.load("mage.png"))
    {
        //在imagelabel中放置图像
        showWidget->imageLabel->setPixmap(QPixmap::fromImage(img));
    }
    connect(fontComboBox, SIGNAL(activated(QString)), this, SLOT(ShowFontComboBox(QString)));
    connect(sizeComboBox, SIGNAL(activated(QString)), this, SLOT(ShowSizeSpinBox(QString)));
    connect(boldBtn, SIGNAL(clicked()), this, SLOT(ShowBoldBtn()));
    connect(italicBtn, SIGNAL(clicked()), this, SLOT(ShowItalicBtn()));
    connect(underlineBtn, SIGNAL(clicked()), this, SLOT(ShowUnderlineBtn()));
    connect(colorBtn, SIGNAL(clicked()), this, SLOT(ShowColorBtn()));
    connect(showWidget->text, SIGNAL(currentCharFormatChanged(QTextCharFormat &)), this, SLOT(ShowCurrentFormatChanged(const QTextCharFormat &)));
}
void ImgProcessor::ShowFontComboBox(QString comboStr)
{
    //设置字体
    QTextCharFormat fmt;//创建一个QTextCharFormat对象
    fmt.setFontFamily(comboStr);//选择的字体名称设置给QTextCharFormat对象
    mergeFormat(fmt);//将新的格式应用到光标选区内的字符。
}
void ImgProcessor::mergeFormat(QTextCharFormat format)
{
    //设置格式
    QTextCursor cursor = showWidget->text->textCursor();//获得编辑框中的光标
    if(!cursor.hasSelection())
    {
        cursor.select(QTextCursor::WordUnderCursor);
    }
    cursor.mergeCharFormat(format);
    showWidget->text->mergeCurrentCharFormat(format);
}
void ImgProcessor::ShowSizeSpinBox(QString spinValue)
{
    //设置字号
    qDebug() << spinValue << "--" << spinValue.toFloat();
    QTextCharFormat fmt;
    fmt.setFontPointSize(spinValue.toFloat());
    showWidget->text->mergeCurrentCharFormat(fmt);
}
void ImgProcessor::ShowBoldBtn()
{
    //设置选中的字体加粗
    QTextCharFormat fmt;
    fmt.setFontWeight(boldBtn->isChecked() ? QFont::Bold : QFont::Normal);
    showWidget->text->mergeCurrentCharFormat(fmt);
}
void ImgProcessor::ShowItalicBtn()
{
    //设置字体斜体
    QTextCharFormat fmt;
    fmt.setFontItalic(italicBtn->isChecked());
    showWidget->text->mergeCurrentCharFormat(fmt);
}
void ImgProcessor::ShowUnderlineBtn()
{
    //设置文字下划线
    QTextCharFormat fmt;
    fmt.setFontUnderline(underlineBtn->isChecked());
    showWidget->text->mergeCurrentCharFormat(fmt);
}
void ImgProcessor::ShowColorBtn()
{
    //设置颜色
    QColor color = QColorDialog::getColor(Qt::red, this);
    if(color.isValid())
    {
        QTextCharFormat fmt;
        fmt.setForeground(color);
        showWidget->text->mergeCurrentCharFormat(fmt);
    }
}
void ImgProcessor::ShowCurrentFormatChanged(const QTextCharFormat &fmt)
{
    fontComboBox->setCurrentIndex(fontComboBox->findText(fmt.fontFamily()));
    sizeComboBox->setCurrentIndex(sizeComboBox->findText(QString::number(fmt.fontPointSize())));
    boldBtn->setChecked(fmt.font().bold());
    italicBtn->setChecked(fmt.fontItalic());
    underlineBtn->setChecked(fmt.fontUnderline());
}

Qt5 排版功能

//排版
    void showList(int);
    void showAlignment(QAction *act);
    void showCursorPositionChanged();
    //排版功能
    QLabel *listLabel;
    QComboBox *listComboBox;
    QActionGroup *actGrp;
    QAction *leftAction;
    QAction *rightAction;
    QAction *centerAction;
    QAction *justifyAction;
    QToolBar *listToolBar;

//排版格式
    listLabel = new QLabel(tr("排序"));
    listComboBox = new QComboBox;
    listComboBox->addItem("Standard");
    listComboBox->addItem("QTextListFormat::ListDisc");
    listComboBox->addItem("QTextListFormat::ListCircle");
    listComboBox->addItem("QTextListFormat::ListSquare");
    listComboBox->addItem("QTextListFormat::ListDecimal");
    listComboBox->addItem("QTextListFormat::ListLowerAlpha");
    listComboBox->addItem("QTextListFormat::ListUpperAlpha");
    listComboBox->addItem("QTextListFormat::ListLowerRoman");
    listComboBox->addItem("QTextListFormat::ListUpperRoman");
    //排版格式
    connect(listComboBox, SIGNAL(activated(int)), this, SLOT(showList(int)));
    connect(showWidget->text->document(), SIGNAL(undoAvailable(bool)), redoAction, SLOT(setEnabled(bool)));
    connect(showWidget->text->document(), SIGNAL(redoAvailable(bool)), redoAction, SLOT(setEnabled(bool)));
    connect(showWidget->text->document(), SIGNAL(cursorPositionChanged()), this, SLOT(showCursorPositionChanged()));
void ImgProcessor::ShowCurrentFormatChanged(const QTextCharFormat &fmt)
{
    fontComboBox->setCurrentIndex(fontComboBox->findText(fmt.fontFamily()));
    sizeComboBox->setCurrentIndex(sizeComboBox->findText(QString::number(fmt.fontPointSize())));
    boldBtn->setChecked(fmt.font().bold());
    italicBtn->setChecked(fmt.fontItalic());
    underlineBtn->setChecked(fmt.fontUnderline());
}
void ImgProcessor::showAlignment(QAction *act)
{
    if(act == leftAction)
    {
        //左对齐
        showWidget->text->setAlignment(Qt::AlignLeft);
    }
    if(act == rightAction)
    {
        //右对齐
        showWidget->text->setAlignment(Qt::AlignRight);
    }
    if(act == centerAction)
    {
        //居中
        showWidget->text->setAlignment(Qt::AlignCenter);
    }
    if(act == justifyAction)
    {
        //两端对齐
        showWidget->text->setAlignment(Qt::AlignJustify);
    }
}
void ImgProcessor::showCursorPositionChanged()
{
    if(showWidget->text->alignment() == Qt::AlignLeft)
        leftAction->setChecked(true);
    if(showWidget->text->alignment() == Qt::AlignRight)
        rightAction->setChecked(true);
    if(showWidget->text->alignment() == Qt::AlignCenter)
        centerAction->setChecked(true);
    if(showWidget->text->alignment() == Qt::AlignJustify)
        justifyAction->setChecked(true);
}
void ImgProcessor::showList(int index)
{
    //获得编辑框的QTextCursor对象指针
    QTextCursor cursor = showWidget->text->textCursor();
    if(index != 0)
    {
        QTextListFormat::Style style = QTextListFormat::ListDisc;//从下拉列表中旋转确定QTextlistformat的style属性值。
        switch (index) {
        default:
        case 1:
            style = QTextListFormat::ListDisc;
            break;
        case 2:
            style = QTextListFormat::ListCircle;
            break;
        case 3:
            style = QTextListFormat::ListSquare;
            break;
        case 4:
            style = QTextListFormat::ListDecimal;
            break;
        case 5:
            style = QTextListFormat::ListLowerAlpha;
            break;
        case 6:
            style = QTextListFormat::ListUpperAlpha;
            break;
        case 7:
            style = QTextListFormat::ListLowerRoman;
            break;
        case 8:
            style = QTextListFormat::ListUpperRoman;
        }
        //设置缩进值
        cursor.beginEditBlock();
        QTextBlockFormat blockFmt = cursor.blockFormat();//获得段落缩进值
        QTextListFormat listFmt;
        if(cursor.currentList())
        {
            listFmt = cursor.currentList()->format();
        }
        else{
            listFmt.setIndent(blockFmt.indent() + 1);
            blockFmt.setIndent(0);
            cursor.setBlockFormat(blockFmt);
        }
        listFmt.setStyle(style);
        cursor.createList(listFmt);
        cursor.endEditBlock();
    }
    else{
        QTextBlockFormat bfmt;
        bfmt.setObjectIndex(-1);
        cursor.mergeBlockFormat(bfmt);
    }
}

main.cpp

#include "imgprocessor.h"
#include 
int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    QFont f("ZYSong18030", 12);
    a.setFont(f);
    ImgProcessor w;
    w.show();
    return a.exec();
}

最终实现效果及全部代码

全部代码

main.cpp

#include "imgprocessor.h"
#include 
int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    QFont f("ZYSong18030", 12);
    a.setFont(f);
    ImgProcessor w;
    w.show();
    return a.exec();
}

imgprocessor.h

#ifndef IMGPROCESSOR_H
#define IMGPROCESSOR_H
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include "showwidget.h"
#include 
class ImgProcessor : public QMainWindow
{
    Q_OBJECT
public:
    ImgProcessor(QWidget *parent = nullptr);
    ~ImgProcessor();
    void createActions();
    void createMenus();
    void createToolBars();
    void loadFile(QString filename);
    void mergeFormat(QTextCharFormat);
private slots:
    void showNewFile();//新建文件
    void showOpenFile();//打开文件
    void showPrintText();//打印文本文件
    void showPrintImage();//打印图片
    void showZoomIn();//放大
    void showZoomOut();//缩小
    void showRotate90(); //旋转90
    void showRotate180();
    void showRotate270();
protected slots:
    //字体格式
    void ShowFontComboBox(QString comboStr);
    void ShowSizeSpinBox(QString spinValue);
    void ShowBoldBtn();
    void ShowItalicBtn();
    void ShowUnderlineBtn();
    void ShowColorBtn();
    void ShowCurrentFormatChanged(const QTextCharFormat &fmt);
    //排版
    void showList(int);
    void showAlignment(QAction *act);
    void showCursorPositionChanged();
private:
    QMenu *fileMenu;
    QMenu *zoomMenu;
    QMenu *rotateMenu;
    QMenu *mirrorMenu;
    QImage img;
    QString fileName;
    ShowWidget *showWidget; //文件菜单项
    QAction *openFileAction;
    QAction *NewFileAction;
    QAction *printTRextAction;
    QAction *printImageAction;
    QAction *exitAction;
    QAction *copyAction;    //编辑菜单项
    QAction *cutAction;
    QAction *pasteAction;
    QAction *aboutAction;
    QAction *zoomInAction;
    QAction *zoomOutAction;
    QAction *rotate90Action;    //旋转菜单项
    QAction *rotate180Action;
    QAction *rotate270Action;
    QAction *mirrorVerticalAction;  //镜像菜单项
    QAction *mirrorHorizontalAction;
    QAction *undoAction;
    QAction *redoAction;
    QToolBar *fileTool; //工具栏
    QToolBar *zoomTool;
    QToolBar *rotateTool;
    QToolBar *mirrorTool;
    QToolBar *doToolBar;
    //字体格式功能
    QLabel *fontLabel;
    QFontComboBox *fontComboBox;
    QLabel *fontLabel2;
    QComboBox *sizeComboBox;
    QToolButton *boldBtn;
    QToolButton *italicBtn;
    QToolButton *underlineBtn;
    QToolButton *colorBtn;
    QToolBar *fontToolBar;
    //排版功能
    QLabel *listLabel;
    QComboBox *listComboBox;
    QActionGroup *actGrp;
    QAction *leftAction;
    QAction *rightAction;
    QAction *centerAction;
    QAction *justifyAction;
    QToolBar *listToolBar;
};
#endif // IMGPROCESSOR_H

imgprocessor.cpp

#include "imgprocessor.h"
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
ImgProcessor::ImgProcessor(QWidget *parent)
    : QMainWindow(parent)
{
    setWindowTitle(tr("Easy Word"));    //窗口标题
    showWidget = new ShowWidget(this);
    setCentralWidget(showWidget);
    //在工具栏上嵌入控件
    //设置字体
    fontLabel = new QLabel(tr("字体:"));
    fontComboBox = new QFontComboBox;
    fontComboBox->setFontFilters(QFontComboBox::ScalableFonts);
    fontLabel2 = new QLabel(tr("字号:"));
    sizeComboBox = new QComboBox;
    QFontDatabase db;
    foreach(int size, db.standardSizes())
        sizeComboBox->addItem(QString::number(size));
    boldBtn = new QToolButton;
    boldBtn->setIcon(QIcon("bold.png"));
    boldBtn->setCheckable(true);
    italicBtn = new QToolButton;
    italicBtn->setIcon(QIcon("italic.png"));
    italicBtn->setCheckable(true);
    underlineBtn = new QToolButton;
    underlineBtn->setIcon(QIcon("under.png"));
    underlineBtn->setCheckable(true);
    colorBtn = new QToolButton;
    colorBtn->setIcon(QIcon("color.png"));
    colorBtn->setCheckable(true);
    //排版格式
    listLabel = new QLabel(tr("排序"));
    listComboBox = new QComboBox;
    listComboBox->addItem("Standard");
    listComboBox->addItem("QTextListFormat::ListDisc");
    listComboBox->addItem("QTextListFormat::ListCircle");
    listComboBox->addItem("QTextListFormat::ListSquare");
    listComboBox->addItem("QTextListFormat::ListDecimal");
    listComboBox->addItem("QTextListFormat::ListLowerAlpha");
    listComboBox->addItem("QTextListFormat::ListUpperAlpha");
    listComboBox->addItem("QTextListFormat::ListLowerRoman");
    listComboBox->addItem("QTextListFormat::ListUpperRoman");
    //创建动作、菜单、工具栏
    createActions();
    createMenus();
    createToolBars();
    if(img.load("mage.png"))
    {
        //在imagelabel中放置图像
        showWidget->imageLabel->setPixmap(QPixmap::fromImage(img));
    }
    //字体设置
    connect(fontComboBox, SIGNAL(activated(QString)), this, SLOT(ShowFontComboBox(QString)));
    connect(sizeComboBox, SIGNAL(activated(QString)), this, SLOT(ShowSizeSpinBox(QString)));
    connect(boldBtn, SIGNAL(clicked()), this, SLOT(ShowBoldBtn()));
    connect(italicBtn, SIGNAL(clicked()), this, SLOT(ShowItalicBtn()));
    connect(underlineBtn, SIGNAL(clicked()), this, SLOT(ShowUnderlineBtn()));
    connect(colorBtn, SIGNAL(clicked()), this, SLOT(ShowColorBtn()));
    connect(showWidget->text, SIGNAL(currentCharFormatChanged(QTextCharFormat &)), this, SLOT(ShowCurrentFormatChanged(const QTextCharFormat &)));
    //排版格式
    connect(listComboBox, SIGNAL(activated(int)), this, SLOT(showList(int)));
    connect(showWidget->text->document(), SIGNAL(undoAvailable(bool)), redoAction, SLOT(setEnabled(bool)));
    connect(showWidget->text->document(), SIGNAL(redoAvailable(bool)), redoAction, SLOT(setEnabled(bool)));
    connect(showWidget->text->document(), SIGNAL(cursorPositionChanged()), this, SLOT(showCursorPositionChanged()));
}
ImgProcessor::~ImgProcessor()
{
}
void ImgProcessor::createActions()
{
    //“打开”动作
    openFileAction = new QAction(QIcon("open.png"), tr("打开"), this);
    openFileAction->setShortcut(tr("Ctrl+O"));
    openFileAction->setStatusTip(tr("打开一个文件"));
    connect(openFileAction, SIGNAL(triggered()), this, SLOT(showOpenFile()));
    //“新建”动作
    NewFileAction = new QAction(QIcon("new.png"), tr("新建"), this);
    NewFileAction->setShortcut(tr("Ctrl+N"));
    NewFileAction->setStatusTip(tr("新建一个文件"));
    connect(NewFileAction, SIGNAL(triggered()), this, SLOT(showNewFile()));
    //“退出”动作
    exitAction = new QAction(tr("退出"), this);
    exitAction->setShortcut(tr("Ctrl+Q"));
    exitAction->setStatusTip(tr("退出程序"));
    connect(exitAction, SIGNAL(triggered()), this, SLOT(close()));
    //“复制”动作
    copyAction = new QAction(QIcon("copy.png"), tr("复制"), this);
    copyAction->setShortcut(tr("Ctrl+C"));
    copyAction->setStatusTip(tr("复制文件"));
    connect(copyAction, SIGNAL(triggered()), showWidget->text, SLOT(copy()));
    //“剪切”动作
    cutAction = new QAction(QIcon("cut.png"), tr("剪切"), this);
    cutAction->setShortcut(tr("Ctrl+X"));
    cutAction->setStatusTip(tr("剪切文件"));
    connect(cutAction, SIGNAL(truggered()), showWidget->text, SLOT(cut()));
    //“粘贴”动作
    pasteAction = new QAction(QIcon("paste.png"), tr("粘贴"), this);
    pasteAction->setShortcut(tr("Ctrl+V"));
    pasteAction->setStatusTip(tr("粘贴文件"));
    connect(pasteAction, SIGNAL(triggered()), showWidget->text, SLOT(paste()));
    //“关于”动作
    aboutAction = new QAction(tr("关于"), this);
    connect(aboutAction, SIGNAL(triggered()), this, SLOT(QApplication::aboutQt()));
    //“打印文本”动作
    printTRextAction = new QAction(QIcon("printText.png"), tr("打印文本"), this);
    printTRextAction->setStatusTip(tr("打印一个文本"));
    connect(printTRextAction, SIGNAL(triggered()), this, SLOT(showPrintText()));
    //“打印图像”动作
    printImageAction = new QAction(QIcon("printImage.png"), tr("打印图像"), this);
    printImageAction->setStatusTip(tr("打印一幅图像"));
    connect(printImageAction, SIGNAL(triggered()), this, SLOT(showPrintImage()));
    //“放大”动作
    zoomInAction = new QAction(QIcon("zoomin.png"), tr("放大"), this);
    zoomInAction->setStatusTip(tr("放大一张照片"));
    connect(zoomInAction, SIGNAL(triggered()), this, SLOT(showZoomIn()));
    //“缩小”动作
    zoomOutAction = new QAction(QIcon("zoomout.png"), tr("缩小"), this);
    zoomOutAction->setStatusTip(tr("缩小一张照片"));
    connect(zoomOutAction, SIGNAL(triggered()), this, SLOT(showZoomOut()));
    //实现图像旋转的动作
    //90
    rotate90Action = new QAction(QIcon("rotate90.png"), tr("旋转90"), this);
    rotate90Action->setStatusTip(tr("将一幅图像旋转90度"));
    connect(rotate90Action, SIGNAL(triggered()), this, SLOT(showRotate90()));
    //180
    rotate180Action = new QAction(QIcon("rotate180.png"), tr("旋转180"), this);
    rotate180Action->setStatusTip(tr("将一幅图像旋转180度"));
    connect(rotate180Action, SIGNAL(triggered()), this, SLOT(showRotate180()));
    //270
    rotate270Action = new QAction(QIcon("rotate270.png"), tr("旋转270"), this);
    rotate270Action->setStatusTip(tr("将一副图像旋转270度"));
    connect(rotate270Action, SIGNAL(triggered()), this, SLOT(showRotate270()));
    //实现图像镜像的动作
    //纵向
    mirrorVerticalAction = new QAction(QIcon("mirrorV.png"), tr("纵向镜像"), this);
    mirrorVerticalAction->setStatusTip(tr("对一幅图像纵向镜像"));
    //横向
    mirrorHorizontalAction = new QAction(QIcon("mirrorH.png"), tr("横向镜像"), this);
    mirrorHorizontalAction->setStatusTip(tr("对一副图像横向镜像"));
    //实现撤销和恢复动作
    undoAction = new QAction(QIcon("undo.png"), tr("撤销"), this);
    connect(undoAction, SIGNAL(triggered()), showWidget->text, SLOT(undo()));
    redoAction = new QAction(QIcon("redo.png"), tr("重做"), this);
    connect(redoAction, SIGNAL(triggered()), showWidget->text, SLOT(redo()));
    //排序：左对齐、右对齐、居中和两端对齐
    actGrp = new QActionGroup(this);
    leftAction = new QAction(QIcon("left.png"), "左对齐", actGrp);
    leftAction->setCheckable(true);
    rightAction = new QAction(QIcon("right.png"), "右对齐", actGrp);
    rightAction->setCheckable(true);
    centerAction = new QAction(QIcon("center.png"), "居中", actGrp);
    centerAction->setCheckable(true);
    justifyAction = new QAction(QIcon("justify.png"), "两端对齐", actGrp);
    justifyAction->setCheckable(true);
    connect(actGrp, SIGNAL(triggered(QAction *)), this, SLOT(showAlignment(QAction *)));
}
void ImgProcessor::createMenus()
{
    //文件菜单
    fileMenu = menuBar()->addMenu(tr("文件"));
    fileMenu->addAction(openFileAction);
    fileMenu->addAction(NewFileAction);
    fileMenu->addAction(printTRextAction);
    fileMenu->addAction(printImageAction);
    fileMenu->addSeparator();//插入空格
    fileMenu->addAction(exitAction);
    //缩放菜单
    zoomMenu = menuBar()->addMenu(tr("编辑"));
    zoomMenu->addAction(copyAction);
    zoomMenu->addAction(cutAction);
    zoomMenu->addAction(pasteAction);
    zoomMenu->addAction(aboutAction);
    zoomMenu->addSeparator();
    zoomMenu->addAction(zoomInAction);
    zoomMenu->addAction(zoomOutAction);
    //旋转菜单
    rotateMenu = menuBar()->addMenu(tr("旋转"));
    rotateMenu->addAction(rotate90Action);
    rotateMenu->addAction(rotate180Action);
    rotateMenu->addAction(rotate270Action);
    //镜像菜单
    mirrorMenu = menuBar()->addMenu(tr("镜像"));
    mirrorMenu->addAction(mirrorVerticalAction);
    mirrorMenu->addAction(mirrorHorizontalAction);
}
void ImgProcessor::createToolBars()
{
    //文件工具条
    fileTool = addToolBar("File");
    fileTool->addAction(openFileAction);
    fileTool->addAction(NewFileAction);
    fileTool->addAction(printTRextAction);
    fileTool->addAction(printImageAction);
    //编辑工具条
    zoomTool = addToolBar("Edit");
    zoomTool->addAction(copyAction);
    zoomTool->addAction(cutAction);
    zoomTool->addAction(pasteAction);
    zoomTool->addSeparator();
    zoomTool->addAction(zoomInAction);
    zoomTool->addAction(zoomOutAction);
    //旋转工具条
    rotateTool = addToolBar("rotate");
    rotateTool->addAction(rotate90Action);
    rotateTool->addAction(rotate180Action);
    rotateTool->addAction(rotate270Action);
    //撤销和重做工具条
    doToolBar = addToolBar("doEdit");
    doToolBar->addAction(undoAction);
    doToolBar->addAction(redoAction);
    //字体工具条
    fontToolBar = addToolBar("font");
    fontToolBar->addWidget(fontLabel);
    fontToolBar->addWidget(fontLabel2);
    fontToolBar->addWidget(sizeComboBox);
    fontToolBar->addSeparator();
    fontToolBar->addWidget(boldBtn);
    fontToolBar->addWidget(italicBtn);
    fontToolBar->addWidget(underlineBtn);
    fontToolBar->addSeparator();
    fontToolBar->addWidget(colorBtn);
    //排版工具条
    listToolBar = addToolBar("list");
    listToolBar->addWidget(listLabel);
    listToolBar->addWidget(listComboBox);
    listToolBar->addSeparator();
    listToolBar->addActions(actGrp->actions());
}
void ImgProcessor::showNewFile()
{
    ImgProcessor *newImgProcessor = new ImgProcessor;
    newImgProcessor->show();
}
void ImgProcessor::loadFile(QString filename)
{
    qDebug() << "file name :" << filename;
    QFile file(filename);
    if(file.open(QIODevice::ReadOnly | QIODevice::Text))
    {
        QTextStream textStream(&file);
        while(!textStream.atEnd())
        {
            showWidget->text->append(textStream.readLine());
            qDebug() << "read line";
        }
    }
}
void ImgProcessor::showOpenFile()
{
    fileName = QFileDialog::getOpenFileName(this);
    if(!fileName.isEmpty())
    {
        if(showWidget->text->document()->isEmpty())
        {
            loadFile(fileName);
        }
        else
        {
            ImgProcessor *newImgProcessor = new ImgProcessor;
            newImgProcessor->show();
            newImgProcessor->loadFile(fileName);
        }
    }
}
void ImgProcessor::showPrintText()
{
    QPrinter printer;
    QPrintDialog printDialog(&printer, this);//创建一个QPrintDialog对象。
    if(printDialog.exec())
    {
        //获得QTextEdit 对象的文档
        QTextDocument *doc = showWidget->text->document();
        doc->print(&printer);
    }
}
void ImgProcessor::showPrintImage()
{
    QPrinter printer;
    QPrintDialog printDialog(&printer, this);
    if(printDialog.exec())
    {
        QPainter painter(&printer);
        QRect rect = painter.viewport();//获得QPainter 对象的视图矩形区域
        QSize size = img.size();
        //安装图片的比例大小重新设定视图矩形区域
        size.scale(rect.size(), Qt::KeepAspectRatio);
        painter.setViewport(rect.x(), rect.y(), size.width(), size.height());
        painter.setWindow(img.rect());
        painter.drawImage(0, 0, img);
    }
}
void ImgProcessor::showZoomIn()
{
    if(img.isNull())//有效判断
    {
        return;
    }
    QMatrix martix;//声明一个QMatrix类的实例
    martix.scale(2, 2); //该参数决定x方向和y方向的缩放比例
    img = img.transformed(martix);
    showWidget->imageLabel->setPixmap(QPixmap::fromImage(img));
}
void ImgProcessor::showZoomOut()
{
    if(img.isNull())
    {
        return ;
    }
    QMatrix matrix;
    matrix.scale(0.5, 0.5);
    img = img.transformed(matrix);
    showWidget->imageLabel->setPixmap(QPixmap::fromImage(img));
}
void ImgProcessor::showRotate90()
{
    if(img.isNull())
    {
        return ;
    }
    QMatrix matrix;
    matrix.rotate(90);
    img = img.transformed(matrix);
    showWidget->imageLabel->setPixmap(QPixmap::fromImage(img));
}
void ImgProcessor::showRotate180()
{
    if(img.isNull())
    {
        return ;
    }
    QMatrix matrix;
    matrix.rotate(180);
    img = img.transformed(matrix);
    showWidget->imageLabel->setPixmap(QPixmap::fromImage(img));
}
void ImgProcessor::showRotate270()
{
    if(img.isNull())
    {
        return ;
    }
    QMatrix matrix;
    matrix.rotate(270);
    img = img.transformed(matrix);
    showWidget->imageLabel->setPixmap(QPixmap::fromImage(img));
}
void ImgProcessor::ShowFontComboBox(QString comboStr)
{
    //设置字体
    QTextCharFormat fmt;//创建一个QTextCharFormat对象
    fmt.setFontFamily(comboStr);//选择的字体名称设置给QTextCharFormat对象
    mergeFormat(fmt);//将新的格式应用到光标选区内的字符。
}
void ImgProcessor::mergeFormat(QTextCharFormat format)
{
    //设置格式
    QTextCursor cursor = showWidget->text->textCursor();//获得编辑框中的光标
    if(!cursor.hasSelection())
    {
        cursor.select(QTextCursor::WordUnderCursor);
    }
    cursor.mergeCharFormat(format);
    showWidget->text->mergeCurrentCharFormat(format);
}
void ImgProcessor::ShowSizeSpinBox(QString spinValue)
{
    //设置字号
    qDebug() << spinValue << "--" << spinValue.toFloat();
    QTextCharFormat fmt;
    fmt.setFontPointSize(spinValue.toFloat());
    showWidget->text->mergeCurrentCharFormat(fmt);
}
void ImgProcessor::ShowBoldBtn()
{
    //设置选中的字体加粗
    QTextCharFormat fmt;
    fmt.setFontWeight(boldBtn->isChecked() ? QFont::Bold : QFont::Normal);
    showWidget->text->mergeCurrentCharFormat(fmt);
}
void ImgProcessor::ShowItalicBtn()
{
    //设置字体斜体
    QTextCharFormat fmt;
    fmt.setFontItalic(italicBtn->isChecked());
    showWidget->text->mergeCurrentCharFormat(fmt);
}
void ImgProcessor::ShowUnderlineBtn()
{
    //设置文字下划线
    QTextCharFormat fmt;
    fmt.setFontUnderline(underlineBtn->isChecked());
    showWidget->text->mergeCurrentCharFormat(fmt);
}
void ImgProcessor::ShowColorBtn()
{
    //设置颜色
    QColor color = QColorDialog::getColor(Qt::red, this);
    if(color.isValid())
    {
        QTextCharFormat fmt;
        fmt.setForeground(color);
        showWidget->text->mergeCurrentCharFormat(fmt);
    }
}
void ImgProcessor::ShowCurrentFormatChanged(const QTextCharFormat &fmt)
{
    fontComboBox->setCurrentIndex(fontComboBox->findText(fmt.fontFamily()));
    sizeComboBox->setCurrentIndex(sizeComboBox->findText(QString::number(fmt.fontPointSize())));
    boldBtn->setChecked(fmt.font().bold());
    italicBtn->setChecked(fmt.fontItalic());
    underlineBtn->setChecked(fmt.fontUnderline());
}
void ImgProcessor::showAlignment(QAction *act)
{
    if(act == leftAction)
    {
        //左对齐
        showWidget->text->setAlignment(Qt::AlignLeft);
    }
    if(act == rightAction)
    {
        //右对齐
        showWidget->text->setAlignment(Qt::AlignRight);
    }
    if(act == centerAction)
    {
        //居中
        showWidget->text->setAlignment(Qt::AlignCenter);
    }
    if(act == justifyAction)
    {
        //两端对齐
        showWidget->text->setAlignment(Qt::AlignJustify);
    }
}
void ImgProcessor::showCursorPositionChanged()
{
    if(showWidget->text->alignment() == Qt::AlignLeft)
        leftAction->setChecked(true);
    if(showWidget->text->alignment() == Qt::AlignRight)
        rightAction->setChecked(true);
    if(showWidget->text->alignment() == Qt::AlignCenter)
        centerAction->setChecked(true);
    if(showWidget->text->alignment() == Qt::AlignJustify)
        justifyAction->setChecked(true);
}
void ImgProcessor::showList(int index)
{
    //获得编辑框的QTextCursor对象指针
    QTextCursor cursor = showWidget->text->textCursor();
    if(index != 0)
    {
        QTextListFormat::Style style = QTextListFormat::ListDisc;//从下拉列表中旋转确定QTextlistformat的style属性值。
        switch (index) {
        default:
        case 1:
            style = QTextListFormat::ListDisc;
            break;
        case 2:
            style = QTextListFormat::ListCircle;
            break;
        case 3:
            style = QTextListFormat::ListSquare;
            break;
        case 4:
            style = QTextListFormat::ListDecimal;
            break;
        case 5:
            style = QTextListFormat::ListLowerAlpha;
            break;
        case 6:
            style = QTextListFormat::ListUpperAlpha;
            break;
        case 7:
            style = QTextListFormat::ListLowerRoman;
            break;
        case 8:
            style = QTextListFormat::ListUpperRoman;
        }
        //设置缩进值
        cursor.beginEditBlock();
        QTextBlockFormat blockFmt = cursor.blockFormat();//获得段落缩进值
        QTextListFormat listFmt;
        if(cursor.currentList())
        {
            listFmt = cursor.currentList()->format();
        }
        else{
            listFmt.setIndent(blockFmt.indent() + 1);
            blockFmt.setIndent(0);
            cursor.setBlockFormat(blockFmt);
        }
        listFmt.setStyle(style);
        cursor.createList(listFmt);
        cursor.endEditBlock();
    }
    else{
        QTextBlockFormat bfmt;
        bfmt.setObjectIndex(-1);
        cursor.mergeBlockFormat(bfmt);
    }
}

showwidget.h

#ifndef SHOWWIDGET_H
#define SHOWWIDGET_H
#include 
#include 
#include 
#include 
class ShowWidget : public QWidget
{
    Q_OBJECT
public:
    explicit ShowWidget(QWidget *parent = nullptr);
    QImage img;
    QLabel *imageLabel;
    QTextEdit *text;
signals:
public slots:
};
#endif // SHOWWIDGET_H

showwidget.cpp

#include "showwidget.h"
#include
ShowWidget::ShowWidget(QWidget *parent) : QWidget(parent)
{
    imageLabel = new QLabel;
    imageLabel->setScaledContents(true);
    text = new QTextEdit;
    QHBoxLayout *mainLayout = new QHBoxLayout(this);
    mainLayout->addWidget(imageLabel);
    mainLayout->addWidget(text);
}

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Qt5——主窗口

文章目录

Qt5 主窗口构成

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示例：文本编辑器

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Qt5 文件操作功能

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Qt5 文本编辑功能

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Qt5 排版功能

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Qt5——主窗口

文章目录

Qt5 主窗口构成

基本元素

示例：文本编辑器

示例步骤及代码

Qt5 文件操作功能

新建文件

打开文件

打印文件

Qt5 图像坐标变换

缩放功能

旋转功能

Qt5 文本编辑功能

实现文本编辑的具体步骤：

Qt5 排版功能

最终实现效果及全部代码

全部代码

热门文章

最新文章

相关电子书

推荐镜像