HtmlInputCheckBox.OnServerChange(EventArgs) 方法

定義

命名空間:
System.Web.UI.HtmlControls
組件:
System.Web.dll

引發 ServerChange 事件。 這種方法讓你能直接處理事件。

protected:
 virtual void OnServerChange(EventArgs ^ e);
protected virtual void OnServerChange(EventArgs e);
abstract member OnServerChange : EventArgs -> unit
override this.OnServerChange : EventArgs -> unit
Protected Overridable Sub OnServerChange (e As EventArgs)

參數

e
EventArgs

包含事件資訊的 A EventArgs 。

範例

以下程式碼範例示範如何指定並編寫事件處理 ServerChange 程序。

<%@ 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">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
    <title>HtmlInputCheckBox Sample</title>
<script language="C#" runat="server">

      void Button1_Click(object sender, EventArgs e) 
      { 

         if (Prev_Check_State.Value == Check1.Checked.ToString())
            Span2.InnerHtml = "CheckBox1 did not change state between clicks.";

         if (Check1.Checked)
         {          
            Span1.InnerHtml = "CheckBox1 is selected!";
            Prev_Check_State.Value="True";
         }         
         else
         { 
            Span1.InnerHtml = "CheckBox1 is not selected!";
            Prev_Check_State.Value="False";
         }
         
      }

      void Server_Changed(object sender, EventArgs e) 
      {
         Span2.InnerHtml = "CheckBox1 changed state between clicks.";
      }

   </script>

</head>

<body>

   <h3>HtmlInputCheckBox Sample</h3>

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

      <input id="Check1" 
             type="checkbox"
             onserverchange="Server_Changed" 
             runat="server"/> 
 
      CheckBox1   

      <span id="Span1" 
            style="color:red" 
            runat="server"/>

      <br />

      <input type="button" 
             id="Button1" 
             value="Enter" 
             onserverclick="Button1_Click" 
             runat="server"/>
      
      <br /><br />

      <span id="Span2" 
            runat="server"/>

      <input type="hidden" id="Prev_Check_State"
                       visible="false"
                       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">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
    <title>HtmlInputCheckBox Sample</title>
<script language="VB" runat="server">

    Sub Button1_Click(sender As Object, e As EventArgs)
        
        If Prev_Check_State.Value = Check1.Checked.ToString() Then
            Span2.InnerHtml = "CheckBox1 did not change state between clicks."
        End If
        If Check1.Checked = True Then
            Span1.InnerHtml = "CheckBox1 is selected!"
            Prev_Check_State.Value = "True"
        Else
            Span1.InnerHtml = "CheckBox1 is not selected!"
            Prev_Check_State.Value = "False"
        End If
    End Sub 'Button1_Click
     

    Sub Server_Changed(sender As Object, e As EventArgs)
        Span2.InnerHtml = "CheckBox1 changed state between clicks."
    End Sub 'Server_Changed

  </script>

</head>

<body>

   <h3>HtmlInputCheckBox Sample</h3>

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

      <input id="Check1" 
             type="checkbox"
             onserverchange="Server_Changed" 
             runat="server"/> 
 
      CheckBox1   

      <span id="Span1" 
            style="color:red" 
            runat="server"/>

      <br />

      <input type="button" 
             id="Button1" 
             value="Enter" 
             onserverclick="Button1_Click" 
             runat="server"/>
      
      <br /><br />

      <span id="Span2" 
            runat="server"/>

      <input type="hidden" id="Prev_Check_State"
                       visible="false"
                       runat="server"/>
   </form>

</body>
</html>

備註

當網頁提交到伺服器並 HtmlInputCheckBox 控制狀態與前一篇文章不同時，此事件會被觸發。 此方法允許您覆蓋基礎實作，並提供事件的自訂處理程序。

Note

控制項必須啟用檢視狀態，事件才能 ServerChange 正常運作。

發起事件會透過代理呼叫事件處理者。 欲了解更多資訊，請參閱 處理與提升事件。

此 OnServerChange 方法也允許衍生類別在不附加代理的情況下處理事件。 這是在衍生類別中處理事件的首選技術。

給繼承者的注意事項

在導出類別中覆寫 OnServerChange(EventArgs) 時，務必呼叫基底類別的方法 OnServerChange(EventArgs) ，讓註冊代理接收事件。

適用於

另請參閱