ClientScriptManager.RegisterStartupScript Method (Type, String, String, Boolean) (System.Web.UI)

RegisterStartupScript Method (Type,...

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Microsoft Visual Studio 2008/.NET Framework 3.5

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.NET Framework Class Library

ClientScriptManager..::.RegisterStartupScript Method (Type, String, String, Boolean)

Registers the startup script with the Page object using a type, a key, a script literal, and a Boolean value indicating whether to add script tags.

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

Syntax

Visual Basic (Declaration)

Public Sub RegisterStartupScript ( _
    type As Type, _
    key As String, _
    script As String, _
    addScriptTags As Boolean _
)

Visual Basic (Usage)

Dim instance As ClientScriptManager
Dim type As Type
Dim key As String
Dim script As String
Dim addScriptTags As Boolean

instance.RegisterStartupScript(type, _
    key, script, addScriptTags)

public void RegisterStartupScript(
    Type type,
    string key,
    string script,
    bool addScriptTags
)

Visual C++

public:
void RegisterStartupScript(
    Type^ type, 
    String^ key, 
    String^ script, 
    bool addScriptTags
)

JScript

public function RegisterStartupScript(
    type : Type, 
    key : String, 
    script : String, 
    addScriptTags : boolean
)

Parameters

type: Type: System..::.Type
The type of the startup script to register.

key: Type: System..::.String
The key of the startup script to register.

script: Type: System..::.String
The startup script literal to register.

addScriptTags: Type: System..::.Boolean
A Boolean value indicating whether to add script tags.

Exceptions

Exception	Condition
ArgumentNullException	type is nullNothingnullptra null reference (Nothing in Visual Basic).

Remarks

A startup script is uniquely identified by its key and its type. Scripts with the same key and type are considered duplicates. Only one script with a given type and key pair can be registered with the page. Attempting to register a script that is already registered does not create a duplicate of the script.

Call the IsStartupScriptRegistered method to determine whether a startup script with a given key and type pair is already registered and avoid unnecessarily attempting to add the script.

In this overload of the RegisterStartupScript method, you can indicate whether the script provided in the script parameter is wrapped with a <script> element block by using the addScriptTags parameter. Setting addScriptTags to true indicates that script tags will be added automatically.

The script block added by the RegisterStartupScript method executes when the page finishes loading but before the page's OnLoad event is raised. The script blocks are not guaranteed to be output in the order they are registered. If the order of the script blocks is important, use a StringBuilder object to gather the scripts together in a single string, and then register them all in a single client script block.

Examples

The following code example demonstrates the use of the RegisterStartupScript method. Note that the addScriptTags parameter is set to false so the beginning and closing script tags are included with the script parameter.

Visual Basic

<%@ Page Language="VB" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">

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

    ' Define the name and type of the client scripts on the page.
    Dim csname1 As String = "PopupScript"
    Dim csname2 As String = "ButtonClickScript"
    Dim cstype As Type = Me.GetType()

    ' Get a ClientScriptManager reference from the Page class.
    Dim cs As ClientScriptManager = Page.ClientScript

    ' Check to see if the startup script is already registered.
    If (Not cs.IsStartupScriptRegistered(cstype, csname1)) Then

      Dim cstext1 As String = "alert('Hello World');"
      cs.RegisterStartupScript(cstype, csname1, cstext1, True)

    End If

    ' Check to see if the client script is already registered.
    If (Not cs.IsClientScriptBlockRegistered(cstype, csname2)) Then

      Dim cstext2 As New StringBuilder()
            cstext2.Append("<script type=""text/javascript""> function DoClick() {")
      cstext2.Append("Form1.Message.value='Text from client script.'} </")
      cstext2.Append("script>")
      cs.RegisterClientScriptBlock(cstype, csname2, cstext2.ToString(), False)

    End If

  End Sub

</script>

<html  >
  <head>
    <title>ClientScriptManager Example</title>
  </head>
  <body>
     <form id="Form1"
         runat="server">
        <input type="text" id="Message" /> <input type="button" value="ClickMe" onclick="DoClick()" />
     </form>
  </body>
</html>

<%@ 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)
  {
    // Define the name and type of the client scripts on the page.
    String csname1 = "PopupScript";
    String csname2 = "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, csname1))
    {
      String cstext1 = "alert('Hello World');";
      cs.RegisterStartupScript(cstype, csname1, cstext1, true);
    }

    // Check to see if the client script is already registered.
    if (!cs.IsClientScriptBlockRegistered(cstype, 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>");
      cs.RegisterClientScriptBlock(cstype, csname2, cstext2.ToString(), false);
    }
  }
</script>
<html  >
  <head>
    <title>ClientScriptManager Example</title>
  </head>
  <body>
     <form id="Form1"
         runat="server">
        <input type="text" id="Message" /> <input type="button" value="ClickMe" onclick="DoClick()" />
     </form>
  </body>
</html>

Platforms

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

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

Version Information

.NET Framework

Supported in: 3.5, 3.0, 2.0

Reference

ClientScriptManager Class

ClientScriptManager Members

RegisterStartupScript Overload

System.Web.UI Namespace

RegisterStartupScript

Script