To dynamically generate the javascript code in ASP.NET page, developers can use
ClientScriptManager.RegisterStartupScript or
ClientScriptManager.RegisterClientScriptBlock.
The following example shows how to register startup javascript code and callback javascript code for a button.
<%@ Page Language="C#"%>
<script runat="server">
public void Page_Load(Object sender, EventArgs e)
{
// Define the name and type of the client scripts on the page.
String strClientScriptName1 = "PopupScript";
String strClientScriptName2 = "ButtonClickScript";
Type cstype = this.GetType();
// Get a ClientScriptManager reference from the Page class.
ClientScriptManager cs = Page.ClientScript;
// Check to see if the startup script is already registered.
if (!cs.IsStartupScriptRegistered(cstype, strClientScriptName1))
{
String cstext1 = "alert('Hello World');";
cs.RegisterStartupScript(cstype, strClientScriptName1, cstext1, true);
}
// Check to see if the client script is already registered.
if (!cs.IsClientScriptBlockRegistered(cstype, strClientScriptName2))
{
StringBuilder cstext2 = new StringBuilder();
cstext2.Append("<script type=text/javascript> function DoClick() {");
cstext2.Append("Form1.Message.value=Form1.TextBox1.value} </");
cstext2.Append("script>");
cs.RegisterClientScriptBlock(cstype, strClientScriptName2, cstext2.ToString(), false);
}
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
<title>ClientScriptManager Example</title>
</head>
<body>
<form id="Form1"
runat="server">
<input type="text" id="Message" /> <input type="button" value="ClickMe" onclick="DoClick()" />
<asp:textbox id="TextBox1" runat="server" text="Sample Text" />
</form>
</body>
</html>