.Net 4.5中事件的標記擴展

Question

WPF未定義用於事件的標記擴展，第三方能夠創建可用於事件的標記擴展。現在WPF 4.5支持事件的標記擴展。任何人都可以通過一個優雅的例子來幫助如何在.Net 4.5中實現這一點？

Answer 1

事件標記擴展允許您爲事件使用標記擴展，直到WPF 4.5爲止，它們只能用於屬性。例如：

<Canvas ClipToBounds="True" Background="White" 
     MouseLeftButtonDown="{local:EventToCommand StartPaintCommand}" 
     MouseMove="{local:EventToCommand AddLineCommand}" 
     MouseLeftButtonUp="{local:EventToCommand EndPaintCommand}"> 
</Canvas> 

可以找到一個完整的例子here。

Answer 2

命令

{EB：EventBinding}（簡單的命名模式來查找命令）

{EB：EventBinding命令=的CommandName}

CommandParameter

$ E（ EventAgrs）

$ this或$ this。物業

串

https://github.com/JonghoL/EventBindingMarkup

Answer 3

這是一個非常靈活的標記擴展我寫的，可以直接事件綁定到你的視圖模型方法的一個例子：

http://www.singulink.com/CodeIndex/post/building-the-ultimate-wpf-event-method-binding-extension

用法：

<!-- Basic usage --> 
<Button Click="{data:MethodBinding OpenFromFile}" Content="Open" /> 

<!-- Pass in a binding as a method argument --> 
<Button Click="{data:MethodBinding Save, {Binding CurrentItem}}" Content="Save" /> 

<!-- Another example of a binding, but this time to a property on another element --> 
<ComboBox x:Name="ExistingItems" ItemsSource="{Binding ExistingItems}" /> 
<Button Click="{data:MethodBinding Edit, {Binding SelectedItem, ElementName=ExistingItems}}" /> 

<!-- Pass in a hard-coded method argument, XAML string automatically converted to the proper type --> 
<ToggleButton Checked="{data:MethodBinding SetWebServiceState, True}" 
       Content="Web Service" 
       Unchecked="{data:MethodBinding SetWebServiceState, False}" /> 

<!-- Pass in sender, and match method signature automatically --> 
<Canvas PreviewMouseDown="{data:MethodBinding SetCurrentElement, {data:EventSender}, ThrowOnMethodMissing=False}"> 
    <controls:DesignerElementTypeA /> 
    <controls:DesignerElementTypeB /> 
    <controls:DesignerElementTypeC /> 
</Canvas> 

    <!-- Pass in EventArgs --> 
<Canvas MouseDown="{data:MethodBinding StartDrawing, {data:EventArgs}}" 
     MouseMove="{data:MethodBinding AddDrawingPoint, {data:EventArgs}}" 
     MouseUp="{data:MethodBinding EndDrawing, {data:EventArgs}}" /> 

<!-- Support binding to methods further in a property path --> 
<Button Content="SaveDocument" Click="{data:MethodBinding CurrentDocument.DocumentService.Save, {Binding CurrentDocument}}" /> 

查看模型方法簽名：

public void OpenFromFile(); 
public void Save(DocumentModel model); 
public void Edit(DocumentModel model); 

public void SetWebServiceState(bool state); 

public void SetCurrentElement(DesignerElementTypeA element); 
public void SetCurrentElement(DesignerElementTypeB element); 
public void SetCurrentElement(DesignerElementTypeC element); 

public void StartDrawing(MouseEventArgs e); 
public void AddDrawingPoint(MouseEventArgs e); 
public void EndDrawing(MouseEventArgs e); 

public class Document 
{ 
    // Fetches the document service for handling this document 
    public DocumentService DocumentService { get; } 
} 

public class DocumentService 
{ 
    public void Save(Document document); 
}