HtmlInputImage.OnServerClick(ImageClickEventArgs) Metodo

Definizione

Spazio dei nomi:
System.Web.UI.HtmlControls
Assembly:
System.Web.dll

Genera l'evento ServerClick.

protected:
 virtual void OnServerClick(System::Web::UI::ImageClickEventArgs ^ e);
protected virtual void OnServerClick(System.Web.UI.ImageClickEventArgs e);
abstract member OnServerClick : System.Web.UI.ImageClickEventArgs -> unit
override this.OnServerClick : System.Web.UI.ImageClickEventArgs -> unit
Protected Overridable Sub OnServerClick (e As ImageClickEventArgs)

Parametri

e
ImageClickEventArgs

Oggetto ImageClickEventArgs contenente i dati dell'evento.

Esempio

Nell'esempio di codice seguente viene illustrato come specificare e codificare un gestore per l'evento ServerClick per determinare le coordinate in cui l'utente fa clic sul HtmlInputImage controllo.

<%@ Page Language="C#" AutoEventWireup="True" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
      
  protected void  ImageBtn_Click(object sender, ImageClickEventArgs e)
  {

    // Write the click coordinates to the Span1 element.
    Span1.InnerText = "You clicked at (" + e.X.ToString() +
                      ", " + e.Y.ToString() + ").";
  }
  
</script>

<html xmlns="http://www.w3.org/1999/xhtml" > 
<head runat="server">
    <title>Click the Image </title>
</head>
<body>

   <form id="form1" runat="server">

      <h3>Click the Image </h3>

      <input type="image"
             alt="Image Alternate Text"
             src="Image1.jpg" 
             onserverclick="ImageBtn_Click"
             runat="server" id="Image1"/>

      <br />
      <br />

      <span id="Span1" 
            runat="server"/>

   </form>

</body>
</html>

<%@ Page Language="VB" AutoEventWireup="True" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
      
  Sub ImageBtn_Click(ByVal Sender As Object, ByVal E As ImageClickEventArgs)

    ' Write the click coordinates to the Span1 element.
    Span1.InnerText = "You clicked at (" & E.X.ToString() & _
                      ", " & E.Y.ToString() & ")."
      
  End Sub

</script>

<html xmlns="http://www.w3.org/1999/xhtml" > 
<head runat="server">
    <title>Click the Image </title>
</head>
<body>

   <form id="form1" runat="server">

      <h3>Click the Image </h3>

      <input type="image"
             alt="Image Alternate Text"
             src="Image1.jpg" 
             onserverclick="ImageBtn_Click"
             runat="server"/>

      <br />
      <br />

      <span id="Span1" 
            runat="server"/>

   </form>

</body>
</html>

<%@ Page Language="C#" AutoEventWireup="True" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
      
  void ImageBtn_Click(Object sender, ImageClickEventArgs e)
  {

    // Display the coordinates of the position where the image 
    // was clicked. 
    Span1.InnerText = "You clicked at (" + e.X.ToString() +
                      ", " + e.Y.ToString() + ").";

  }

  void Page_Load(Object sender, EventArgs e)
  {

    // Create an EventHandler delegate for the method you want to 
    // handle the event, and then add it to the list of methods called
    // when the event is raised.
    Image1.ServerClick += new ImageClickEventHandler(this.ImageBtn_Click);

  }

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>HtmlInputImage ServerClick Example </title>
</head>
<body>

   <form id="form1" runat="server">

      <h3>HtmlInputImage ServerClick Example </h3>

      <input type="image"
             id="Image1"
             src="Image.jpg" 
             alt="Image"
             runat="server"/>

      <br />

      <span id="Span1" 
            runat="server"/>

   </form>

</body>
</html>

<%@ Page Language="VB" AutoEventWireup="True" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
      
  Sub ImageBtn_Click(ByVal sender As Object, ByVal e As ImageClickEventArgs)

    ' Display the coordinates of the position where the image 
    ' was clicked.
    Span1.InnerText = "You clicked at (" & e.X.ToString() & _
                      ", " & e.Y.ToString() & ")."
      
  End Sub
  
  Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
      
    ' Create an EventHandler delegate for the method you want to 
    ' handle the event, and then add it to the list of methods called
    ' when the event is raised.
    AddHandler Image1.ServerClick, AddressOf ImageBtn_Click

  End Sub

</script>

<html xmlns="http://www.w3.org/1999/xhtml" > 
<head runat="server">
    <title>HtmlInputImage ServerClick Example </title>
</head>
<body>

   <form id="form1" runat="server">

      <h3>HtmlInputImage ServerClick Example </h3>

      <input type="image"
             id="Image1"
             src="Image.jpg" 
             alt="Image"
             runat="server"/>

      <br />

      <span id="Span1" 
            runat="server"/>

   </form>

</body>
</html>

Commenti

L'evento ServerClick viene generato quando l'utente fa clic su un HtmlInputImage controllo.

Le coordinate in cui l'utente fa clic su un HtmlInputImage controllo possono essere determinate utilizzando le ImageClickEventArgs.X proprietà e ImageClickEventArgs.Y dell'oggetto System.Web.UI.ImageClickEventArgs . L'oggetto System.Web.UI.ImageClickEventArgs viene passato come parametro al gestore eventi definito dall'utente.

Note

L'origine (0, 0) si trova nell'angolo superiore sinistro dell'immagine.

La generazione di un evento richiama il gestore eventi tramite un delegato. Per altre informazioni, vedere Gestione e generazione di eventi.

Il OnServerClick metodo consente anche alle classi derivate di gestire l'evento senza associare un delegato. Questa è la tecnica preferita per gestire l'evento in una classe derivata.

Note per gli eredi

Quando si esegue l'override OnServerClick(ImageClickEventArgs) in una classe derivata, assicurarsi di chiamare il metodo della OnServerClick(ImageClickEventArgs) classe di base in modo che i delegati registrati ricevano l'evento.

Si applica a

Vedi anche