HtmlInputText.OnServerChange(EventArgs) 方法
定義
重要
部分資訊涉及發行前產品,在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊,不做任何明確或隱含的瑕疵擔保。
引發 ServerChange 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
範例
下列程式碼範例示範如何指定 和 撰寫 ServerChange 事件的處理常式程式碼。 自訂事件處理常式會更新網頁上的標籤,以顯示在 HTML 元素中 <input type=text>
輸入的文字值。
<%@ 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>HtmlInputText ServerChange Example</title>
<script runat="server">
void Server_Change(object sender, EventArgs e)
{
Span1.InnerHtml = "You typed: " + Text1.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.
Text1.ServerChange += new System.EventHandler(this.Server_Change);
}
</script>
</head>
<body>
<form id="form1" runat="server">
<h3>HtmlInputText ServerChange Example</h3>
Enter a value in the input field below and
click the Submit button.
<br />
<input type="text"
id="Text1"
runat="server"/>
<br />
<br />
<input type="submit"
id="Button1"
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">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
<title>HtmlInputText ServerChange Example</title>
<script runat="server">
Sub Server_Change(ByVal sender As Object, ByVal e As EventArgs)
Span1.InnerHtml = String.Format("You typed: {0}", Text1.Value)
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 Text1.ServerChange, AddressOf Server_Change
End Sub
</script>
</head>
<body>
<form id="form1" runat="server">
<h3>HtmlInputText ServerChange Example</h3>
Enter a value in the input field below and
click the Submit button.
<br />
<input type="text"
id="Text1"
runat="server"/>
<br />
<input type="submit"
id="Button1"
value="Submit"
runat="server"/>
<br />
<span id="Span1"
runat="server" />
</form>
</body>
</html>
備註
當 ServerChange 伺服器上的 屬性變更時 Value ,就會引發 事件。
注意
控制項必須啟用檢視狀態, ServerChange 事件才能正常運作。
引發事件會透過委派叫用此事件處理常式。 如需詳細資訊,請參閱 處理和引發事件。
OnServerChange 方法也允許衍生類別處理事件,而不用附加委派。 這是在衍生類別中處理事件的慣用技巧。
給繼承者的注意事項
當在衍生類別中覆寫 OnServerChange(EventArgs) 時,請確定呼叫基底類別的 OnServerChange(EventArgs) 方法,使已註冊的委派能接收到事件。