ScriptManager Control Overview

Artigo
10/22/2014

The ScriptManager control manages client script for AJAX-enabled ASP.NET Web pages. By default, the ScriptManager control registers the script for the Microsoft AJAX Library with the page. This enables client script to use the type system extensions and to support features such as partial-page rendering and Web-service calls.

This topic contains the following sections:

Scenarios
Background
Code Examples
Class Reference

Scenarios

You must use a ScriptManager control on a page to enable the following AJAX features of ASP.NET:

Client-script functionality of the Microsoft AJAX Library, and any custom script that you want to send to the browser. For more information, see Creating Custom Client Script by Using the Microsoft AJAX Library.
Partial-page rendering, which enables regions on the page to be independently refreshed without a postback. The ASP.NET UpdatePanel, UpdateProgress, and Timer controls require a ScriptManager control in order to support partial-page rendering.
JavaScript proxy classes for Web services, which enable you to use client script to access Web services and specially marked methods in ASP.NET pages. It does this by exposing the Web services and page methods as strongly typed objects.
JavaScript classes to access ASP.NET authentication, profile, and roles application services.

Background

When a page contains one or more UpdatePanel controls, the ScriptManager control manages partial-page rendering in the browser. The control interacts with the page life cycle to update the parts of the page that are inside UpdatePanel controls. For more information, see Partial-Page Rendering Overview.

The EnablePartialRendering property of the ScriptManager control determines whether a page participates in partial-page updates. By default, the EnablePartialRendering property is true. Therefore, by default partial-page rendering is enabled when you add a ScriptManager control to the page. For information about how to use the UpdatePanel control with the ScriptManager control, see Introduction to the UpdatePanel Control and Creating a Simple ASP.NET Page with Multiple UpdatePanel Controls.

Handling Partial-page Rendering Errors

During partial-page rendering, you can handle errors by doing the following:

Set the AllowCustomErrorsRedirect property. This determines how the custom error section of the Web.config file is used when an error occurs during an asynchronous postback.
Handle the ScriptManager control's AsyncPostBackError event, which is raised when there is a page error during an asynchronous postback.
Set the AsyncPostBackErrorMessage property, which is the error message that is sent to the browser.

Using Type System Extensions

The Microsoft AJAX Library adds type-system extensions to JavaScript that provide namespaces, inheritance, interfaces, enumerations, reflection, and helper functions for strings and arrays. These extensions provide functionality in client script that is like that of the .NET Framework. They enable you to write AJAX-enabled ASP.NET applications in a structured way that improves maintainability, makes it easier to add features, and makes it easier to layer functionality. Adding a ScriptManager control to an ASP.NET Web page automatically includes the type-system extensions so that you can use the library in client script. For more information, see Creating Custom Client Script by Using the Microsoft AJAX Library.

Registering Custom Script

Use the ScriptManager control to manage resources that you have created for controls that participate in partial-page updates. Resources include scripts, styles, hidden fields, and arrays. The Scripts collection of the ScriptManager control contains a ScriptReference object for each script that is available to the browser. You can specify the scripts declaratively or programmatically.

The ScriptManager control also exposes registration methods that you can use to manage client script and hidden fields programmatically. When you are registering script or hidden fields that support partial-page updates, you must call registration methods of the ScriptManager control. (To register scripts that are not needed for partial-page updates, you use methods of the ClientScriptManager class.)

Note

Any scripts on the page that are registered by using the ScriptManager control and all event-handling script must be inside the form element on the page. Otherwise the script will not be registered or executed.

For a list of the ClientScriptManager controls registration methods, see Creating Custom Client Script by Using the Microsoft AJAX Library and the ClientScriptManager class overview.

Registering Web Services

To register a Web service that you want to call from an AJAX-enabled ASP.NET page, you register the Web service by adding it to the ScriptManager control's Services collection. The ASP.NET AJAX framework generates a client proxy object for each ServiceReference object in the Services collection. The proxy classes and their strongly typed members simplify using Web services from client script.

You can programmatically add ServiceReference objects to the Services collection to register Web services at run time. For more information, see Web Services in ASP.NET AJAX.

Using Authentication, Profile, and Role Services from Client Script

The Microsoft AJAX Library includes proxy classes for calling the ASP.NET 2.0 forms authentication, profile, and roles application services directly from JavaScript. If you want to use a custom authentication service, you can register it by using the ScriptManager control. For more information, see Using Forms Authentication with ASP.NET AJAX, Using Profile Information with ASP.NET AJAX, and Using Roles Information with ASP.NET AJAX.

The ScriptManagerProxy Class

Only one instance of the ScriptManager control can be added to the page. The page can include the control directly, or indirectly inside a nested component such as a user control, content page for a master page, or nested master page. If a page already contains a ScriptManager control, but a nested or parent component needs additional features of the ScriptManager control, the component can include a ScriptManagerProxy control. For example, the ScriptManagerProxy control enables you to add scripts and services that are specific to nested components.

Code Examples

Sample AJAX Application

Walkthrough: Creating an AJAX-enabled Web Site

Walkthrough: Globalizing a Date by Using Client Script

Creating Custom Client Script by Using the Microsoft AJAX Library

Walkthrough: Creating and Using AJAX-Enabled Web Service

Introduction to the UpdatePanel Control

Introduction to the UpdateProgress Control

Walkthrough: Introduction to the Timer Control

Dynamically Assigning Script References

Creating an Extender Control to Associate a Client Behavior with a Web Server Control

Adding Client Capabilities to a Web Server Control

Creating Custom AJAX Client Controls

Creating Custom Non-Visual Client Components

Class Reference

Class	Description
ScriptManager	A server control that makes script resources available to the browser, which includes the Microsoft AJAX Library and the functionality that enables partial-page rendering.
ScriptManagerProxy	A server control that enables nested components to add script and service references if the page already contains a ScriptManager control.

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