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HtmlTextArea.ServerChange 事件

定義

發生於當 HtmlTextArea 控制項的內容在發佈至伺服器期間時變更。

public:
 event EventHandler ^ ServerChange;
public event EventHandler ServerChange;
member this.ServerChange : EventHandler 
Public Custom Event ServerChange As EventHandler 

事件類型

範例

下列程式碼範例示範如何指定和建立事件的自訂事件處理常式 ServerChange 。 當控制項中 HtmlTextArea 輸入的值超過 10 個字元時,就會顯示訊息。

<%@ 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 Server_Change(Object sender, EventArgs e)
  {

    // The ServerChange event is commonly used for data validation.
    // This method determines whether the comment entered into the
    // HtmlTextArea control is longer than 20 characters.
    if (TextArea1.Value.Length > 20)
      Span1.InnerHtml = "Your comment cannot exceed 20 characters.";
    else
      Span1.InnerHtml = "You wrote: <br />" + TextArea1.Value;

  }

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
   <title>HtmlTextArea ServerChange Example</title>
</head>
<body>

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

      <h3>HtmlTextArea ServerChange Example</h3>

      Enter your comments: <br />

      <textarea rows="2" cols="20" id="TextArea1"
                onserverchange="Server_Change" 
                runat="server"/>

      <br />

      <input type="submit"  
             value="Submit" 
             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 Server_Change(ByVal sender As Object, ByVal e As EventArgs)
         
    ' The ServerChange event is commonly used for data validation.
    ' This method determines whether the comment entered into the
    ' HtmlTextArea control is longer than 20 characters.
    If TextArea1.Value.Length > 20 Then
      Span1.InnerHtml = "Your comment cannot exceed 20 characters."
    Else
      Span1.InnerHtml = "You wrote: <br />" + TextArea1.Value
    End If
      
  End Sub

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
   <title>HtmlTextArea ServerChange Example</title>

</head>
<body>

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

      <h3>HtmlTextArea ServerChange Example</h3>

      Enter your comments: <br />

      <textarea rows="2" cols="20" id="TextArea1"
                onserverchange="Server_Change" 
                runat="server"/>

      <br />

      <input type="submit"  
             value="Submit" 
             runat="server"/>

      <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 Server_Change(Object sender, EventArgs e)
  {
    // The ServerChange event is commonly used for data validation.
    // This method determines whether the comment entered into the
    // HtmlTextArea control is longer than 20 characters.
    if (TextArea1.Value.Length > 20)
    {
      Span1.InnerHtml = "Your comment cannot exceed 20 characters.";
    }
    else
    {
      Span1.InnerHtml = "You wrote: <br />" + TextArea1.Value;
    }

  }

  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.
    TextArea1.ServerChange +=
      new System.EventHandler(this.Server_Change);

  }

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
   <title>HtmlTextArea ServerChange Example</title>
</head>
<body>

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

      <h3>HtmlTextArea ServerChange Example</h3>

      Enter your comments (20 or fewer characters): <br />

      <textarea rows="2" cols="20" id="TextArea1"
                runat="server"/>

      <br />

      <input type="submit"  
             value="Submit" 
             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 Server_Change(ByVal sender As Object, ByVal e As EventArgs)
     
    ' The ServerChange event is commonly used for data validation.
    ' This method determines whether the comment entered into the
    ' HtmlTextArea control is longer than 20 characters.
    If TextArea1.Value.Length > 20 Then
         
      Span1.InnerHtml = "Your comment cannot exceed 20 characters."
         
    Else
         
      Span1.InnerHtml = "You wrote: <br />" + TextArea1.Value
         
    End If
      
  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 TextArea1.ServerChange, AddressOf Server_Change

  End Sub

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
   <title>HtmlTextArea ServerChange Example</title>
</head>

<body>

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

      <h3>HtmlTextArea ServerChange Example</h3>

      Enter your comments (20 or fewer characters): <br />

      <textarea rows="2" cols="20" id="TextArea1"
                runat="server"/>

      <br />

      <input type="submit"  
             value="Submit" 
             runat="server"/>

      <br />

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

   </form>

</body>
</html>

備註

ServerChange當控制項的內容 HtmlTextArea 在貼文到伺服器之間變更時,就會引發 事件。 此事件通常用於在文字方塊中執行資料驗證。

注意

只有在使用者起始張貼至伺服器時,才會引發此事件,例如按一下 submit 按鈕。 此事件不會造成伺服器張貼。

注意

控制項必須啟用 viewstate, ServerChange 事件才能正常運作。

如需如何處理事件的詳細資訊,請參閱 處理和引發事件

適用於

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