HtmlElementEventHandler 委托

定义

命名空间:

System.Windows.Forms

程序集:

System.Windows.Forms.dll

表示将处理 HtmlDocument、HtmlElement 和 HtmlWindow 上的 Click、MouseDown 和相关事件的方法。

public delegate void HtmlElementEventHandler(System::Object ^ sender, HtmlElementEventArgs ^ e);

public delegate void HtmlElementEventHandler(object? sender, HtmlElementEventArgs e);

type HtmlElementEventHandler = delegate of obj * HtmlElementEventArgs -> unit

Public Delegate Sub HtmlElementEventHandler(sender As Object, e As HtmlElementEventArgs)

参数

sender

Object

事件源。

e

HtmlElementEventArgs

包含事件数据的 HtmlElementEventArgs。

示例

以下代码为 MouseDown上的 HtmlDocument、 MouseMove和 MouseUp 事件附加事件处理程序。 此代码示例假定项目具有名为 WebBrowser1的控件实例WebBrowser。

private:
   void webBrowser1_DocumentCompleted( Object^ /*sender*/, System::Windows::Forms::WebBrowserDocumentCompletedEventArgs^ /*e*/ )
   {
      WebBrowser1->Document->MouseDown += gcnew HtmlElementEventHandler( this, &Form1::Document_MouseDown );
      WebBrowser1->Document->MouseMove += gcnew HtmlElementEventHandler( this, &Form1::Document_MouseMove );
      WebBrowser1->Document->MouseUp += gcnew HtmlElementEventHandler( this, &Form1::Document_MouseUp );
   }

   void Document_MouseDown( Object^ /*sender*/, HtmlElementEventArgs^ /*e*/ )
   {
      // Insert your code here.
   }

   void Document_MouseMove( Object^ /*sender*/, HtmlElementEventArgs^ /*e*/ )
   {
      // Insert your code here.
   }

   void Document_MouseUp( Object^ /*sender*/, HtmlElementEventArgs^ /*e*/ )
   {
      // Insert your code here.
   }

private void webBrowser1_DocumentCompleted(object sender, System.Windows.Forms.WebBrowserDocumentCompletedEventArgs e)
{
    WebBrowser1.Document.MouseDown += new HtmlElementEventHandler(Document_MouseDown);
    WebBrowser1.Document.MouseMove += new HtmlElementEventHandler(Document_MouseMove);
    WebBrowser1.Document.MouseUp += new HtmlElementEventHandler(Document_MouseUp);
}

private void Document_MouseDown(object sender, HtmlElementEventArgs e)
{
    // Insert your code here.
}

private void Document_MouseMove(object sender, HtmlElementEventArgs e)
{
    // Insert your code here.
}

private void Document_MouseUp(object sender, HtmlElementEventArgs e)
{
    // Insert your code here.
}

Private Sub WebBrowser1_DocumentCompleted(ByVal sender As Object, ByVal e As System.Windows.Forms.WebBrowserDocumentCompletedEventArgs) Handles WebBrowser1.DocumentCompleted
    Dim Doc As HtmlDocument = WebBrowser1.Document

    AddHandler Doc.MouseDown, New HtmlElementEventHandler(AddressOf Document_MouseDown)
    AddHandler Doc.MouseMove, New HtmlElementEventHandler(AddressOf Document_MouseMove)
    AddHandler Doc.MouseUp, New HtmlElementEventHandler(AddressOf Document_MouseUp)
End Sub

Private Sub Document_MouseDown(ByVal sender As Object, ByVal e As HtmlElementEventArgs)
    ' Insert your code here.
End Sub

Private Sub Document_MouseMove(ByVal sender As Object, ByVal e As HtmlElementEventArgs)
    ' Insert your code here.
End Sub

Private Sub Document_MouseUp(ByVal sender As Object, ByVal e As HtmlElementEventArgs)
    ' Insert your code here.
End Sub

注解

创建 HtmlElementEventHandler 委托时，需要标识将处理该事件的方法。 若要将事件与事件处理程序关联，请将该委托的一个实例添加到事件中。 除非移除了该委托，否则每当发生该事件时就会调用事件处理程序。 有关事件处理程序委托的详细信息，请参阅 处理和引发事件。

必须等到 HTML 文档完成加载才能将事件处理程序附加到文档。 如果在加载完成之前尝试附加处理程序，附加操作可能会失败。 在新文档中附加事件处理程序的最佳位置是控件的DocumentCompletedWebBrowser事件处理程序中。

扩展方法