WPF中不是所有的控件都有Command属性的,如果窗体我需要在ViewModel中处理Loaded事件命令,或者其他事件的命令时,很难都过绑定Command完成,必须要注册依赖属性或事件等,太麻烦了。我喜欢简约、有效的方式,现在我和大家一起分享一下。
场景,我需要处理Button的Click和MouseMove事件,但又避免用后置代码,尽量要在ViewModel中获取。单独一个Click可以通过Button的Command来完成,在前两篇文章中我已介绍过,现在就来处理MouseMove事件,这是需要一个System.Windows.Interactivity.dll,该dll是安装Blend后才有的,在C:\Program Files\Microsoft SDKs\Expression\Blend\.NETFramework\v4.0\Libraries目录中,然后我们仍需要Prism.dll。
xaml:
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<Window x:Class= "WpfApplication1.Window2" xmlns:i= "clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity" xmlns:vm= "clr-namespace:WpfApplication1" Title= "Window2"
Height= "124"
Width= "214" > <Window.DataContext> <vm:Window2ViewModel /> </Window.DataContext> <Grid> <Button Name= "btn"
Content= "Button"
Height= "33"
HorizontalAlignment= "Left"
Margin= "40,24,0,0"
VerticalAlignment= "Top"
Width= "109" > <i:Interaction.Triggers> <i:EventTrigger EventName= "Click" > <i:InvokeCommandAction Command= "{Binding Command1}"
CommandParameter= "10"
/> </i:EventTrigger> <i:EventTrigger EventName= "MouseMove" > <i:InvokeCommandAction Command= "{Binding Command2}"
CommandParameter= "{Binding ElementName=btn}"
/> </i:EventTrigger> </i:Interaction.Triggers> </Button> </Grid> </Window> |
注意;xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"就是导入Blend的dll,然后在控件内部用<i:Interaction.Triggers/>即可,其它应该一看就知道,我通过事件触发器,来引发ViewModel中两个Command,第二个Command的参数是Button对象,通过ElementName=btn来指定。
ViewModel:
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namespace
WpfApplication1 { public
class
Window2ViewModel { public
ICommand Command1 { get
{ return
new
DelegateCommand< string >((str) => { MessageBox.Show( "Command1 with parameter:" +str); }); } } public
ICommand Command2 { get
{ return
new
DelegateCommand<Button>((button) => { Point p = Mouse.GetPosition(button); button.Content = string .Format( "{0},{1}" , p.X, p.Y); }); } } } } |
MVVM中轻松实现Command绑定(三)任意事件的Command,布布扣,bubuko.com
MVVM中轻松实现Command绑定(三)任意事件的Command
原文:http://www.cnblogs.com/cw_volcano/p/3614861.html