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Page.IsStartupScriptRegistered Method

Note: This API is now obsolete.

Determines whether the client startup script is registered with the Page object.

Namespace:  System.Web.UI
Assembly:  System.Web (in System.Web.dll)

[ObsoleteAttribute("The recommended alternative is ClientScript.IsStartupScriptRegistered(string key). http://go.microsoft.com/fwlink/?linkid=14202")]
public bool IsStartupScriptRegistered(
	string key
)

Parameters

key
Type: System.String

The string key of the startup script to search for.

Return Value

Type: System.Boolean
true if the startup script is registered; otherwise, false.

Call this method before calling Page.RegisterStartupScript to avoid unnecessarily assembling the client-side script. This is particularly important if the script requires a large amount of server resources to create.

The IsStartupScriptRegistered method has been deprecated. Use the IsStartupScriptRegistered method in the ClientScriptManager class.

The following code example demonstrates the use of the RegisterStartupScript method in conjunction with the IsStartupScriptRegistered method. If the ECMAScript written in the code declaration block has not already been registered, as determined by IsStartupScriptRegistered, then a RegisterStartupScript call is made.

<%@ Page Language="C#"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
  public void Page_Load(Object sender, EventArgs e)
  {
    String csname1 = "PopupScript";
    String csname2 = "ButtonClickScript";

    if (!IsClientScriptBlockRegistered(csname1))
    {
        String cstext1 = "<script type=\"text/javascript\">" +
            "alert('Hello World');</" + "script>";
        RegisterStartupScript(csname1, cstext1);
    }

    if (!IsClientScriptBlockRegistered(csname2))
    {
      StringBuilder cstext2 = new StringBuilder();
      cstext2.Append("<script type=\"text/javascript\"> function DoClick() {");
      cstext2.Append("Form1.Message.value='Text from client script.'} </");
      cstext2.Append("script>");
      RegisterClientScriptBlock(csname2, cstext2.ToString());
    }
  }
</script>
<html  >
  <head>
    <title>RegisterClientScriptBlock Example</title>
  </head>
  <body>
     <form id="Form1"
         runat="server">
        <input type="text" id="Message" /> <input type="button" value="ClickMe" onclick="DoClick()" />
     </form>
  </body>
</html>

.NET Framework

Supported in: 1.1, 1.0
Obsolete (compiler warning) in 4.5.2
Obsolete (compiler warning) in 4.5.1
Obsolete (compiler warning) in 4.5
Obsolete (compiler warning) in 4
Obsolete (compiler warning) in 3.5
Obsolete (compiler warning) in 3.5 SP1
Obsolete (compiler warning) in 3.0
Obsolete (compiler warning) in 3.0 SP1
Obsolete (compiler warning) in 3.0 SP2
Obsolete (compiler warning) in 2.0
Obsolete (compiler warning) in 2.0 SP1
Obsolete (compiler warning) in 2.0 SP2

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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