WPF MediaElement实现音乐功能增加

当我们在实际开发中，要想在程序中添加音乐的话，可以使用一个叫做 WPF MediaElement的类。那么具体的使用方法又是怎样的呢？#t#

一个朋友问了我个问题,说怎么在wpf程序中增加音乐.搜索了下msdn看到了个WPF MediaElement.
把用法总结下贴出来.

WPF MediaElement是一个播放audio和video的类.

前台加入以下代码:

< StackPanel Background = "Black" >

< MediaElement Source = "numbers.
wmv" Name = "myMediaElement"

Width = "450" Height = "250"
LoadedBehavior = "Manual"
UnloadedBehavior = "Stop" Stretch = "Fill"

MediaOpened = "Element_MediaOpened"
MediaEnded = "Element_MediaEnded" />

< StackPanel HorizontalAlignment =
"Center" Width = "450"
Orientation = "Horizontal" >

< !-- 播放按钮. -- >

< Image Source = "3D_menu_07.png"
MouseDown = "OnMouseDownPlayMedia"
Margin = "5" />

< !-- 暂停按钮. -- >

< Image Source = "3D_menu_09_2.png"
MouseDown = "OnMouseDownPauseMedia"
Margin = "5" />

< !-- 停止按钮. -- >

< Image Source = "list4_01.png"
MouseDown = "OnMouseDownStopMedia"
Margin = "5" />

< !-- 音量设置. -- >

< TextBlock Foreground = "White"
VerticalAlignment = "Center"
Margin = "5" > Volume < /TextBlock >

< Slider Name = "volumeSlider"
VerticalAlignment = "Center"
ValueChanged = "ChangeMediaVolume"

Minimum = "0" Maximum = "1" Value = "0.5"
Width = "70" />

< !-- 播放速度设置. -- >

< TextBlock Foreground = "White"
Margin = "5" VerticalAlignment =
"Center" > Speed < /TextBlock >

< Slider Name = "speedRatioSlider"
VerticalAlignment = "Center"
ValueChanged = "ChangeMediaSpeedRatio"

Value = "1" Width = "70" />

< !-- 播放进度. -- >

< TextBlock Foreground = "White"
Margin = "5" VerticalAlignment =
"Center" > Seek To < /TextBlock >

< Slider Name = "timelineSlider"
Margin = "5" ValueChanged =
"SeekToMediaPosition" Width = "70" />

< /StackPanel >

< /StackPanel >

后台加入以下WPF MediaElement代码:

void OnMouseDownPlayMedia
(object sender, MouseButton
EventArgs args)  
...{  
myMediaElement.Play();
//播放加载好的视频文件.  
InitializePropertyValues();  
}  
void OnMouseDownPauseMedia
(object sender, MouseButton
EventArgs args)  
...{  
myMediaElement.Pause();//暂停播放  
}  
// Stop the media.  
void OnMouseDownStopMedia
(object sender, MouseButton
EventArgs args)  
...{  
myMediaElement.Stop();
//停止播放,再次播放会从头开始  
}  
private void ChangeMediaVolume
(object sender, RoutedProperty
ChangedEventArgs< double> args)  
...{  
myMediaElement.Volume = 
(double)volumeSlider.Value;//更改音量  
}  
private void ChangeMediaSpeed
Ratio(object sender, 
RoutedPropertyChangedEventArgs
< double> args)  
...{  
myMediaElement.SpeedRatio = 
(double)speedRatioSlider.Value;
//更改播放速度  
}  
//播放开始调用的事件  
private void Element_MediaOpened
(object sender, EventArgs e)  
...{  
//设置播放进度条的***值  
timelineSlider.Maximum = 
myMediaElement.NaturalDuration.
TimeSpan.TotalMilliseconds;  
}  
//播放结束调用事件  
private void Element_MediaEnded
(object sender, EventArgs e)  
...{  
myMediaElement.Stop();  
}  
//播放进度  
private void SeekToMediaPosition
(object sender, RoutedProperty
ChangedEventArgs< double> args)  
...{  
int SliderValue = (int)timeline
Slider.Value;  
TimeSpan ts = new TimeSpan
(0, 0, 0, 0, SliderValue);  
myMediaElement.Position = ts;
//这里跳转到播放的哪个地方  
}  
//点击开始时设置播放的音量和播放速度  
void InitializePropertyValues()  
...{  
myMediaElement.Volume = 
(double)volumeSlider.Value;  
myMediaElement.SpeedRatio = 
(double)speedRatioSlider.Value;  
} 

以上就是WPF MediaElement的相关介绍。