ClientScriptManager.RegisterClientScriptBlock Method

Definition

Registers the client script with the Page object.

Overloads

RegisterClientScriptBlock(Type, String, String)

Registers the client script with the Page object using a type, key, and script literal.

RegisterClientScriptBlock(Type, String, String, Boolean)

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

RegisterClientScriptBlock(Type, String, String)

Registers the client script with the Page object using a type, key, and script literal.

public void RegisterClientScriptBlock (Type type, string key, string script);

Parameters

type
Type

The type of the client script to register.

key
String

The key of the client script to register.

script
String

The client script literal to register.

Examples

The following code example demonstrates the use of the RegisterClientScriptBlock method.

<%@ 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 script on the page.
    String csName = "ButtonClickScript";
    Type csType = this.GetType();

    // Get a ClientScriptManager reference from the Page class.
    ClientScriptManager cs = Page.ClientScript;

    // Check to see if the client script is already registered.
    if (!cs.IsClientScriptBlockRegistered(csType, csName))
    {
      StringBuilder csText = new StringBuilder();
      csText.Append("<script type=\"text/javascript\"> function DoClick() {");
      csText.Append("Form1.Message.value='Text from client script.'; }");
      csText.Append("</script>");
      cs.RegisterClientScriptBlock(csType, csName, csText.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>

Remarks

A client 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 IsClientScriptBlockRegistered method to determine whether a client script with a given key and type pair is already registered and avoid unnecessarily attempting to add the script.

In this overload of the RegisterClientScriptBlock method, you must make sure that the script provided in the script parameter is wrapped in a <script> element block.

The RegisterClientScriptBlock method adds a script block to the top of the rendered page. 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.

See also

Applies to

.NET Framework 4.8.1 and other versions
Product Versions
.NET Framework 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1

RegisterClientScriptBlock(Type, String, String, Boolean)

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

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

Parameters

type
Type

The type of the client script to register.

key
String

The key of the client script to register.

script
String

The client script literal to register.

addScriptTags
Boolean

A Boolean value indicating whether to add script tags.

Exceptions

The client script block type is null.

Examples

The following code example demonstrates the use of the RegisterClientScriptBlock method. Note that the addScriptTags parameter is set to true so the beginning and closing script tags are not included with the script parameter.

<%@ 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 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()" />
     </form>
  </body>
</html>

Remarks

A client 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 IsClientScriptBlockRegistered method to determine whether a client script with a given key and type pair is already registered. This lets you avoid unnecessarily attempting to add the script.

In this overload of the RegisterClientScriptBlock 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 RegisterClientScriptBlock method adds a script block to the top of the rendered page. 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.

See also

Applies to

.NET Framework 4.8.1 and other versions
Product Versions
.NET Framework 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1