Professional ASP.NET 2.0之使用JavaScript处理Pages和Server Controls

最新推荐文章于 2025-09-10 16:16:57 发布

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最新推荐文章于 2025-09-10 16:16:57 发布

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文章标签： javascript c# xhtml ViewUI

原文链接：http://www.cnblogs.com/zhhui/archive/2006/03/22/355855.html

本文介绍了在 ASP.NET 中三种不同的 JavaScript 注册方法：RegisterClientScriptBlock、RegisterStartupScript 和 RegisterClientScriptInclude，并通过示例代码说明了它们的用法及区别。

1.使用 Page.ClientScript.RegisterClientScriptBlock
Listing 4-10: Using the RegisterClientScriptBlock method
VB

<%@ Page Language=”VB” %>

Protected Sub Page_Load()Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs)

Dim myScript As String = “Function AlertHello()function AlertHello() { alert(‘Hello ASP.NET’); }”

Page.ClientScript.RegisterClientScriptBlock(Me.GetType(), “MyScript”, _

myScript, True)

End Sub

</script>

<title>Adding JavaScript</title>

</head>

<body>

<div>

<asp:Button ID=”Button1” Runat=”server” Text=”Button”

OnClientClick=”AlertHello()” />

</div>

</form>

</body>

</html>

<%@ Page Language=”C#” %>

protected void Page_Load(object sender, EventArgs e)

{

string myScript = @”function AlertHello()

{ alert(‘Hello ASP.NET’); }”;

Page.ClientScript.RegisterClientScriptBlock(this.GetType(),

“MyScript”, myScript, true);

}

</script>

运行结果如下：

Adding JavaScript

</title></head>

<body>

<div>

<input type=”hidden” name=”__VIEWSTATE”

value=”/wEPDwUKMTY3NzE5MjIyMGRkiyYSRMg+bcXi9DiawYlbxndiTDo=” />

</div>

<!--

function AlertHello()

{ alert(‘Hello ASP.NET’); }// -->

</script>

<div>

<input type=”submit” name=”Button1” value=”Button” onclick=”AlertHello();”

id=”Button1” />

</div>

</form>

</body>

</html>

2.使用Page.ClientScript.RegisterStartupScript

RegisterStartupScript方法与RegisterClientScriptBlock方法最大的不同是：RegisterStartupScript 把script放置在ASP.NET page的底部，而RegisterClientScriptBlock把script放置在ASP.NET page的顶部。

如果你的页面中有如下代码：

<asp:TextBox ID=”TextBox1” Runat=”server”>Hello ASP.NET</asp:TextBox>

Listing 4-11: Improperly using the RegisterClientScriptBlock method
VB

Protected Sub Page_Load()Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs)

Dim myScript As String = “alert(document.forms[0][‘TextBox1’].value);”

Page.ClientScript.RegisterClientScriptBlock(Me.GetType(), “myKey”, myScript, _

True)

End Sub

protected void Page_Load(object sender, EventArgs e)

{

string myScript = @”alert(document.forms[0][‘TextBox1’].value);”;

Page.ClientScript.RegisterClientScriptBlock(this.GetType(),

“MyScript”, myScript, true);

}

此页面运行时会报错，原因是JavaScript function先于text box被安放于浏览器。因此JavaScript function找不到TextBox1。

Listing 4-12: Using the RegisterStartupScript method
VB

Protected Sub Page_Load()Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs)

Dim myScript As String = “alert(document.forms[0][‘TextBox1’].value);”

Page.ClientScript.RegisterStartupScript(Me.GetType(), “myKey”, myScript, _

True)

End Sub

protected void Page_Load(object sender, EventArgs e)

{

string myScript = @”alert(document.forms[0][‘TextBox1’].value);”;

Page.ClientScript.RegisterStartupScript(this.GetType(),

“MyScript”, myScript, true);

}

这段代码把JavaScript function放置于ASP.NET page底部，因此JavaScript运行时它能找到TextBox1。

3.使用Page.ClientScript.RegisterClientScriptInclude
许多开发者把JavaScript放置在.js文件中，使用RegisterClientScriptInclude方法可以注册.js文件中的JavaScript。
Listing 4-13: Using the RegisterClientScriptInclude method
VB

Dim myScript As String = “myJavaScriptCode.js”

Page.ClientScript.RegisterClientScriptInclude(“myKey”, myScript)

string myScript = “myJavaScriptCode.js”

Page.ClientScript.RegisterClientScriptInclude(“myKey”, myScript);

这将在ASP.NET页面产生如下结构：
<script src=”myJavaScriptCode.js” type=”text/javascript”></script>

转载于:https://www.cnblogs.com/zhhui/archive/2006/03/22/355855.html