Silverlight实用窍门系列：36.Silverlight中播放视频和打印文档【附带源码实例】

在silverlight实际项目中时常会需要播放视频和打印文档，在本节中我们将制作一个最简单的播放视频和打印文档的实例。

一、播放WMV视频

首先我们创建一个Silverlight应用程序SLShowVideo，然后放一个示例Wmv视频在SLShowVideo.web项目的根目录下面。

然后我们在Xaml文档中放入一个MediaElement控件，并写入以下代码：

 MediaElement Height="377" HorizontalAlignment="Left" Margin="8,31,0,0"

 Name="showVideo" VerticalAlignment="Top" Width="583" / 

 Button Content="播 放" Height="28" HorizontalAlignment="Left" Margin="194,428,0,0"

 Name="button1" VerticalAlignment="Top" Width="99" Click="button1_Click_1" / 

 Button Content="暂 停" Height="28" HorizontalAlignment="Left" Margin="333,428,0,0"

 Name="button3" VerticalAlignment="Top" Width="99" Click="button3_Click" / 

 Button Content="停 止" Height="28" HorizontalAlignment="Left" Margin="468,428,0,0"

 Name="button2" VerticalAlignment="Top" Width="99" Click="button2_Click" / 

 Button Content="加载视频" Height="28" HorizontalAlignment="Left" Margin="57,428,0,0"

 Name="button4" VerticalAlignment="Top" Width="99" Click="button1_Click"/ 

最后我们写入以下代码加载视频并且控制视频的播放：

#region 播放视频

private void button1_Click(object sender, RoutedEventArgs e)

 //加载视频

 this.showVideo.Source = new Uri(GetURL()+"/sampleVideo.wmv");

/// summary 

/// 获取当前网站的Url前缀

/// /summary 

/// returns /returns 

public static string GetURL()

 ScriptObject location = (HtmlPage.Window.GetProperty("location") as ScriptObject);

 object r = location.GetProperty("href");

 string URL = r.ToString().Substring(0, r.ToString().LastIndexOf(/));

 //截取到当前SILVERLIGHT程序存放网络URL的前缀

 return URL;

private void button3_Click(object sender, RoutedEventArgs e)

 //暂停

 this.showVideo.Pause();

private void button2_Click(object sender, RoutedEventArgs e)

 //停止

 this.showVideo.Stop();

private void button1_Click_1(object sender, RoutedEventArgs e)

 //播放

 this.showVideo.Play();

#endregion

二、打印文档

首先我们看XAML文档。添加一个Canvas元素，元素内的所有内容就是我们即将要打印（当然你也可以设置打印Grid等元素的内容）。

 Canvas Height="376" HorizontalAlignment="Left" Margin="611,32,0,0" Name="canvas1"

 VerticalAlignment="Top" Width="369" 

 sdk:Label Width="85" Canvas.Left="9" Content="第一个打印程序" Canvas.Top="27" / 

 sdk:Label Canvas.Left="11" Canvas.Top="60" Height="16" Content="第二个打印程序"

 Name="label1" Width="86" / 

 /Canvas 

 Button Content="打印" Height="34" HorizontalAlignment="Left" Margin="747,426,0,0"

 Name="btnPrint" VerticalAlignment="Top" Width="110" Click="btnPrint_Click" / 

在Button事件处理程序中我们添加一下代码打印Canvas元素。

#region 打印文档

PrintDocument print;

private void btnPrint_Click(object sender, RoutedEventArgs e)

 print = new PrintDocument();

 //添加一个打印页面事件以设置需要打印的控件

 print.PrintPage += new EventHandler PrintPageEventArgs (print_PrintPage);

 print.Print("canvas1");

void print_PrintPage(object sender, PrintPageEventArgs e)

 //设置打印this.canvas1的所有内容

 e.PageVisual = this.canvas1;

#endregion

本实例采用VS2010+Silverlight 4.0编写。如需源码请点击 SLShowVideo.zip 下载。期待Silverlight 5 beta的到来。下面我们看实例的效果图：
煦风满裳 程兴亮，专注于C#方面的开发工作，喜欢钻研Silverlight,CIL等方面的知识。平时喜欢看书、写技术博客、摄影、旅游和运动。