最近工作需要做一个鼠标可以拖拽移动图片的功能。
写了几个基本功能，勉强能用。这里记录一下。欢迎大神补充。
这个就是完成的功能。
下边的绿色是一个pictureBox，白色框也是一个pictureBox，他们二者是子父级关系。
绿色是父级，白色框是子级。
这里插一个知识点：关于pictureBox的
白色框的pictureBox，我添加的image属性的图片是一张中心透明四周是白边回来Png图片，这个需要注意一下。
1：子级pictureBox如何在父级PictureBox上透明显示。添加下边这句话：
// 设置背景颜色为系统定义的颜色 pictureBox2.BackColor = Color.Transparent;
2：背景透明设置完成，但是现在还是不能够拖拽四周或四个角改变大小。添加下边这句话：
// 设置pictureBox大小可拖拽 pictureBox2.SizeMode = PictureBoxSizeMode.StretchImage;
到这里，小的pictureBox就已经背景透明并且可拖拽的显示在其父级上边了。
下边是我测试使用的Form1.cs文件的代码：
实例放在文末的压缩包中，有兴趣可以尝试下。
using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Windows.Forms; using System.IO; using System.Threading; namespace cutCScan { public partial class Form1 : Form { // 截取数据，获得对角线两点坐标。取到要截取的平面区域。 // 平面区域中有若干个A扫，取其峰值，上下各加一个固定阈值（50） // 将此块数据都截取下来。 public Form1() { InitializeComponent(); } private void Form1_Load(object sender, EventArgs e) { // 设置背景颜色为系统定义的颜色 pictureBox2.BackColor = Color.Transparent; pictureBox2.Parent = pictureBox1; //pictureBox2.BackgroundImageLayout = ImageLayout.Stretch;//设置背景图片自动适应 // 设置pictureBox大小可拖拽 pictureBox2.SizeMode = PictureBoxSizeMode.StretchImage; } /// <summary> /// 有关鼠标样式的相关枚举 /// </summary> private enum EnumMousePointPosition { MouseSizeNone = 0, //无 MouseSizeRight = 1, //拉伸右边框 MouseSizeLeft = 2, //拉伸左边框 MouseSizeBottom = 3, //拉伸下边框 MouseSizeTop = 4, //拉伸上边框 MouseSizeTopLeft = 5,//拉伸左上角 MouseSizeTopRight = 6,//拉伸右上角 MouseSizeBottomLeft = 7,//拉伸左下角 MouseSizeBottomRight = 8,//拉伸右下角 MouseDrag = 9 //鼠标拖动 } #region 鼠标移动变量 const int Band = 5;//范围半径 const int MinWidth = 10;//最低宽度 const int MinHeight = 10;//最低高度 private EnumMousePointPosition m_MousePointPosition; //鼠标样式枚举 private Point m_lastPoint; //光标上次移动的位置 private Point m_endPoint; //光标移动的当前位置 #endregion /// <summary> /// 鼠标按下事件 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void pictureBox2_MouseDown(object sender, MouseEventArgs e) { m_lastPoint.X = e.X; m_lastPoint.Y = e.Y; m_endPoint.X = e.X; m_endPoint.Y = e.Y; } /// <summary> /// 鼠标离开控件的事件 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void pictureBox2_MouseLeave(object sender, EventArgs e) { m_MousePointPosition = EnumMousePointPosition.MouseSizeNone; this.Cursor = Cursors.Arrow; } /// <summary> /// 鼠标移过控件的事件 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void pictureBox2_MouseMove(object sender, MouseEventArgs e) { Control lCtrl = (sender as Control);//获得事件源 //左键按下移动 if (e.Button == MouseButtons.Left) { switch (m_MousePointPosition) { case EnumMousePointPosition.MouseDrag: lCtrl.Left = lCtrl.Left + e.X - m_lastPoint.X; lCtrl.Top = lCtrl.Top + e.Y - m_lastPoint.Y; break; case EnumMousePointPosition.MouseSizeBottom: lCtrl.Height = lCtrl.Height + e.Y - m_endPoint.Y; m_endPoint.X = e.X; m_endPoint.Y = e.Y; //记录光标拖动的当前点 break; case EnumMousePointPosition.MouseSizeBottomRight: lCtrl.Width = lCtrl.Width + e.X - m_endPoint.X; lCtrl.Height = lCtrl.Height + e.Y - m_endPoint.Y; m_endPoint.X = e.X; m_endPoint.Y = e.Y; //记录光标拖动的当前点 break; case EnumMousePointPosition.MouseSizeRight: lCtrl.Width = lCtrl.Width + e.X - m_endPoint.X; lCtrl.Height = lCtrl.Height + e.Y - m_endPoint.Y; m_endPoint.X = e.X; m_endPoint.Y = e.Y; //记录光标拖动的当前点 break; case EnumMousePointPosition.MouseSizeTop: lCtrl.Top = lCtrl.Top + (e.Y - m_lastPoint.Y); lCtrl.Height = lCtrl.Height - (e.Y - m_lastPoint.Y); break; case EnumMousePointPosition.MouseSizeLeft: lCtrl.Left = lCtrl.Left + e.X - m_lastPoint.X; lCtrl.Width = lCtrl.Width - (e.X - m_lastPoint.X); break; case EnumMousePointPosition.MouseSizeBottomLeft: lCtrl.Left = lCtrl.Left + e.X - m_lastPoint.X; lCtrl.Width = lCtrl.Width - (e.X - m_lastPoint.X); lCtrl.Height = lCtrl.Height + e.Y - m_endPoint.Y; m_endPoint.X = e.X; m_endPoint.Y = e.Y; //记录光标拖动的当前点 break; case EnumMousePointPosition.MouseSizeTopRight: lCtrl.Top = lCtrl.Top + (e.Y - m_lastPoint.Y); lCtrl.Width = lCtrl.Width + (e.X - m_endPoint.X); lCtrl.Height = lCtrl.Height - (e.Y - m_lastPoint.Y); m_endPoint.X = e.X; m_endPoint.Y = e.Y; //记录光标拖动的当前点 break; case EnumMousePointPosition.MouseSizeTopLeft: lCtrl.Left = lCtrl.Left + e.X - m_lastPoint.X; lCtrl.Top = lCtrl.Top + (e.Y - m_lastPoint.Y); lCtrl.Width = lCtrl.Width - (e.X - m_lastPoint.X); lCtrl.Height = lCtrl.Height - (e.Y - m_lastPoint.Y); break; default: break; } if (lCtrl.Width < MinWidth) lCtrl.Width = MinWidth; if (lCtrl.Height < MinHeight) lCtrl.Height = MinHeight; } else { //'判断光标的位置状态 m_MousePointPosition = MousePointPosition(lCtrl.Size, e); switch (m_MousePointPosition) //改变光标 { case EnumMousePointPosition.MouseSizeNone: this.Cursor = Cursors.Arrow;//箭头 break; case EnumMousePointPosition.MouseDrag: this.Cursor = Cursors.SizeAll;//四方向 break; case EnumMousePointPosition.MouseSizeBottom: this.Cursor = Cursors.SizeNS;//南北 break; case EnumMousePointPosition.MouseSizeTop: this.Cursor = Cursors.SizeNS;//南北 break; case EnumMousePointPosition.MouseSizeLeft: this.Cursor = Cursors.SizeWE;//东西 break; case EnumMousePointPosition.MouseSizeRight://*/ this.Cursor = Cursors.SizeWE;//东西 break; case EnumMousePointPosition.MouseSizeBottomLeft: this.Cursor = Cursors.SizeNESW;//东北到南西 break; case EnumMousePointPosition.MouseSizeBottomRight: this.Cursor = Cursors.SizeNWSE;//东南到西北 break; case EnumMousePointPosition.MouseSizeTopLeft: this.Cursor = Cursors.SizeNWSE;//东南到西北 break; case EnumMousePointPosition.MouseSizeTopRight: this.Cursor = Cursors.SizeNESW;//东北到南西 break; default: break; } } } /// <summary> /// 坐标位置判定 /// </summary> /// <param name="size"></param> /// <param name="e"></param> /// <returns></returns> private EnumMousePointPosition MousePointPosition(Size size, System.Windows.Forms.MouseEventArgs e) { if ((e.X >= -1 * Band) | (e.X <= size.Width) | (e.Y >= -1 * Band) | (e.Y <= size.Height)) { if (e.X < Band) { if (e.Y < Band) { return EnumMousePointPosition.MouseSizeTopLeft; } else { if (e.Y > -1 * Band + size.Height) { return EnumMousePointPosition.MouseSizeBottomLeft; } else { return EnumMousePointPosition.MouseSizeLeft; } } } else { if (e.X > -1 * Band + size.Width) { if (e.Y < Band) { return EnumMousePointPosition.MouseSizeTopRight; } else { if (e.Y > -1 * Band + size.Height) { return EnumMousePointPosition.MouseSizeBottomRight; } else { return EnumMousePointPosition.MouseSizeRight; } } } else { if (e.Y < Band) { return EnumMousePointPosition.MouseSizeTop; } else { if (e.Y > -1 * Band + size.Height) { return EnumMousePointPosition.MouseSizeBottom; } else { return EnumMousePointPosition.MouseDrag; } } } } } else { return EnumMousePointPosition.MouseSizeNone; } } } }
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