有时候,我们需要将WPF中的控件自身的XAML代码输出成文本,那么,我们可以使用System.Windows.Markup.XamlWriter.Save()方法来完成此任务。关于XamlWriter.Save()的示例，我曾经在“在WPF中，如何得到任何Object对象的XAML代码？”（http://blog.csdn.net/johnsuna/archive/2007/11/23/1899875.aspx）Blog中有所介绍，此处不再赘述。
使用上述方法时，我们发现，输出的XAML代码并不“标准”，不是格式化的XML代码，我们看这样的代码时，会有一种头晕的感觉。那么，怎样输出成已格式化过的XAML代码呢？
答案是借助System.Xml.XmlWriter及对System.Xml.XmlWriterSettings设置来解决。
代码：
以下代码示例演示在txtBoxXamlCode文本框中显示名为“canvasContent”的Canvas控件的自身XAML代码：
// Line.xaml中的部分关键代码：
<Canvas Width="630" Height="400" Name="canvasContent">
// Line.xaml.cs：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using Shapes = System.Windows.Shapes;
using System.Windows.Markup;
using System.Xml;
namespace BrawDraw.Com.Book.WPF.Demo.Lines
{
/// <summary>
/// Interaction logic for Window1.xaml
/// </summary>
public partial class LineDemo : Window
{
public LineDemo()
{
InitializeComponent();
InitCanvasChildren();
}
private void InitCanvasChildren()
{
double angle = 120;
double centerX = 200;
double centerY = 200;
double strokeThickness = 10;
for (int i = 0; i < 360; i += (int)angle)
{
Shapes.Line lineRotate = new System.Windows.Shapes.Line();
lineRotate.Stroke = new SolidColorBrush(Colors.Black);
lineRotate.X1 = 0;
lineRotate.Y1 = centerY;
lineRotate.X2 = centerX;
lineRotate.Y2 = centerY;
lineRotate.StrokeDashArray = new DoubleCollection(new double[] { 0, 3 });
lineRotate.StrokeThickness = strokeThickness;
lineRotate.StrokeDashCap = PenLineCap.Round;
lineRotate.StrokeStartLineCap = PenLineCap.Round;
lineRotate.StrokeEndLineCap = PenLineCap.Round;
RotateTransform rt = new RotateTransform(i, centerX, centerY);
lineRotate.RenderTransform = rt;
canvasContent.Children.Add(lineRotate);
}
}
// 输出显示未格式化的XAML代码
private void btnViewXaml_Click(object sender, RoutedEventArgs e)
{
txtBoxXamlCode.Text = XamlWriter.Save(canvasContent);
}
// 输出显示已格式化过的XAML代码
private void btnViewFormattedXaml_Click(object sender, RoutedEventArgs e)
{
XmlWriterSettings settings = new XmlWriterSettings();
settings.Indent = true;
settings.IndentChars = new string(' ', 4);
settings.NewLineOnAttributes = true;
StringBuilder sb = new StringBuilder();
XmlWriter xmlWriter = XmlWriter.Create(sb, settings);
XamlWriter.Save(canvasContent, xmlWriter);
txtBoxXamlCode.Text = sb.ToString();
xmlWriter.Close();
sb = null;
}
}
}
运行效果图：
点击显示文字为XamlCode的按钮后，输出的代码为：
<Canvas Name="canvasContent" Width="630" Height="400" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"><Line X1="0" Y1="200" X2="200" Y2="200" Stroke="#FF000000" StrokeThickness="10" StrokeStartLineCap="Round" StrokeEndLineCap="Round" StrokeDashCap="Round" StrokeDashArray="0 3"><Line.RenderTransform><RotateTransform Angle="0" CenterX="200" CenterY="200" /></Line.RenderTransform></Line><Line X1="0" Y1="200" X2="200" Y2="200" Stroke="#FF000000" StrokeThickness="10" StrokeStartLineCap="Round" StrokeEndLineCap="Round" StrokeDashCap="Round" StrokeDashArray="0 3"><Line.RenderTransform><RotateTransform Angle="120" CenterX="200" CenterY="200" /></Line.RenderTransform></Line><Line X1="0" Y1="200" X2="200" Y2="200" Stroke="#FF000000" StrokeThickness="10" StrokeStartLineCap="Round" StrokeEndLineCap="Round" StrokeDashCap="Round" StrokeDashArray="0 3"><Line.RenderTransform><RotateTransform Angle="240" CenterX="200" CenterY="200" /></Line.RenderTransform></Line></Canvas>
点击Formatted Xaml的按钮后，得到的代码为：
<?xml version="1.0" encoding="utf-16"?>
<Canvas
Name="canvasContent"
Width="630"
Height="400" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
<Line
X1="0"
Y1="200"
X2="200"
Y2="200"
Stroke="#FF000000"
StrokeThickness="10"
StrokeStartLineCap="Round"
StrokeEndLineCap="Round"
StrokeDashCap="Round"
StrokeDashArray="0 3">
<Line.RenderTransform>
<RotateTransform
Angle="0"
CenterX="200"
CenterY="200" />
</Line.RenderTransform>
</Line>
<Line
X1="0"
Y1="200"
X2="200"
Y2="200"
Stroke="#FF000000"
StrokeThickness="10"
StrokeStartLineCap="Round"
StrokeEndLineCap="Round"
StrokeDashCap="Round"
StrokeDashArray="0 3">
<Line.RenderTransform>
<RotateTransform
Angle="120"
CenterX="200"
CenterY="200" />
</Line.RenderTransform>
</Line>
<Line
X1="0"
Y1="200"
X2="200"
Y2="200"
Stroke="#FF000000"
StrokeThickness="10"
StrokeStartLineCap="Round"
StrokeEndLineCap="Round"
StrokeDashCap="Round"
StrokeDashArray="0 3">
<Line.RenderTransform>
<RotateTransform
Angle="240"
CenterX="200"
CenterY="200" />
</Line.RenderTransform>
</Line>
</Canvas>
很明显，后者可读性强得多。
