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Sys.Net.WebRequestManager 类

更新：2007 年 11 月

管理由 Sys.Net.WebRequest 对象向关联的执行器对象发出的 Web 请求流。

命名空间：Sys.Net

**继承：**无

Sys.Net.WebRequestManager.memberName;

成员

名称

说明

Sys.Net.WebRequestManager 构造函数

在派生类中实现时，初始化 Sys.Net.WebRequestManager 类的新实例。

Sys.Net.WebRequestManager add_completedRequest 方法

为已完成的 WebRequestManager 请求事件注册处理程序。

Sys.Net.WebRequestManager add_invokingRequest 方法

为 WebRequestManager 的调用请求事件注册一个处理程序。

Sys.Net.WebRequestManager remove_completedRequest 方法

移除 add_completedRequest 方法设置的事件处理程序。

Sys.Net.WebRequestManager remove_invokingRequest 方法

移除 add_invokingRequest 方法设置的事件处理程序。

Sys.Net.WebRequestManager.executeRequest 方法

执行指定的 Web 请求。

Sys.Net.WebRequestManager defaultExecutor 属性

获取或设置 Web 请求的默认执行器。

Sys.Net.WebRequestManager defaultTimeout 属性

获取或设置 Web 请求的默认超时。

Sys.Net.WebRequestManager completedRequest 事件

在处理请求后发生。

Sys.Net.WebRequestManager invokingRequest 事件

针对请求调用处理程序函数时发生。

备注

与 WebRequest 对象关联的默认执行器是 XmlHttpExecutor 类的一个实例。该执行器负责发出实际网络请求。

WebRequestManager 类定义了所有 Web 请求的默认行为，因而无需为每个请求指定低级别网络配置设置。

每个页面仅包含一个 WebRequestManager 实例。但是，您可能具有 WebRequest 类的多个实例和相关的执行器。

示例

下面的示例演示如何使用 WebRequestManager 类设置通用属性以及执行 Web 请求。该示例演示了用来与 WebRequestManager 类进行交互的网页和客户端脚本。

<%@ Page Language="VB" %>

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


<html xmlns="http://www.w3.org/1999/xhtml" >
    <head id="Head1" runat="server">

        <title> WebRequestManager  Example </title>

        <style type="text/css">
            body {  font: 11pt Trebuchet MS;
                    font-color: #000000;
                    padding-top: 72px;
                    text-align: center }

            .text { font: 8pt Trebuchet MS }
        </style>



     </head>

   <body>


    <h2>WebRequestManager Example</h2>

        <form id="form1" runat="server">
            <asp:ScriptManager runat="server" ID="scriptManagerId">
                <Scripts>
                    <asp:ScriptReference Path="WebRequestManager.js" />
                </Scripts>
            </asp:ScriptManager>
        </form>




        <table>
            <tr align="left">
                <td>Make a Web request:</td>
                <td>
                    <button id="Button1" 
                        title="adds and remove handlers, too"  
                        onclick="MakeWebRequest(); return false;">Web Request</button>
                </td>
            </tr>
            <tr align="left">
                <td>Set, get default executor:</td>
                <td>
                    <button id="Button2"  
                        onclick="DefaultExecutor(); return false;">Executor</button>
                </td>
           </tr>
           <tr align="left">
                <td>Set, get default timeout:</td>
                <td>
                    <button id="Button3" 
                        onclick="DefaultTimeout(); return false;">Timeout</button>
                </td>
           </tr>
        </table>


        <hr />

        <div id="ResultId" style="background-color:Aqua;"></div>


    </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">


<html xmlns="http://www.w3.org/1999/xhtml" >
    <head id="Head1" runat="server">

        <title> WebRequestManager  Example </title>

        <style type="text/css">
            body {  font: 11pt Trebuchet MS;
                    font-color: #000000;
                    padding-top: 72px;
                    text-align: center }

            .text { font: 8pt Trebuchet MS }
        </style>



     </head>

   <body>


    <h2>WebRequestManager Example</h2>

        <form id="form1" runat="server">
            <asp:ScriptManager runat="server" ID="scriptManagerId">
                <Scripts>
                    <asp:ScriptReference Path="WebRequestManager.js" />
                </Scripts>
            </asp:ScriptManager>
        </form>





        <table>
            <tr align="left">
                <td>Make a Web request:</td>
                <td>
                    <button id="Button1" 
                        title="adds and remove handlers, too"  
                        onclick="MakeWebRequest(); return false;">Web Request</button>
                </td>
            </tr>
            <tr align="left">
                <td>Set, get default executor:</td>
                <td>
                    <button id="Button2"  
                        onclick="DefaultExecutor(); return false;">Executor</button>
                </td>
           </tr>
           <tr align="left">
                <td>Set, get default timeout:</td>
                <td>
                    <button id="Button3" 
                        onclick="DefaultTimeout(); return false;">Timeout</button>
                </td>
           </tr>
        </table>


        <hr />

        <div id="ResultId" style="background-color:Aqua;"></div>


    </body>

</html>

var displayElement;

function pageLoad()
{
    displayElement = $get("ResultId");
}

// Adds invokingRequest and completedRequest
// handlers, and performs a Web request. 
function MakeWebRequest() 
{
    // Clear the previous results. 
    resultElement.innerHTML = "";

    // Instantiate a Web request.
    wRequest =  new Sys.Net.WebRequest();

    // Set the handler to process the Web request.
    Sys.Net.WebRequestManager.add_completedRequest(On_WebRequestCompleted);

    alert("Added On_WebRequestCompleted handler.");

    // Set the handler to call before the Web request
    // is executed.
    Sys.Net.WebRequestManager.add_invokingRequest(On_InvokingRequest);   

    alert("Added On_InvokingRequest handler.");

    // Set the request Url.  
    wRequest.set_url("getTarget.htm");

    // Execute the request.
    // Notice that you do not use the executeRequest method of
    // the WebRequestManager which is intended for internal 
    // use only as in: Sys.Net.WebRequestManager.executeRequest(wRequest).
    // The correct way to execute a request is the following:
    // wRequest.invoke();
    Sys.Net.WebRequestManager.executeRequest(wRequest);


}

// Removes the event handlers that were previusly added. 
function RemoveDefaultHandlers() 
{
    // Clear the previous results. 
    resultElement.innerHTML = "";

    Sys.Net.WebRequestManager.remove_completedRequest(On_WebRequestCompleted);

    alert("Removed On_WebRequestCompleted handler.");

    Sys.Net.WebRequestManager.remove_invokingRequest(On_InvokingRequest); 

    alert("Removed On_InvokingRequest handler.");

}


// Gets and sets the default executor.
function DefaultExecutor()
{
    // Clear the previous results. 
    resultElement.innerHTML = "";

    // Get system default executor type.
    var sysDefaultExecutor = 
        Sys.Net.WebRequestManager.get_defaultExecutorType();
    alert("Get default executor:" + sysDefaultExecutor);


    // Modify the default executor type.
    Sys.Net.WebRequestManager.set_defaultExecutorType(
    "Sys.Net.CustomExecutor");

    var customDefaultExecutor = 
        Sys.Net.WebRequestManager.get_defaultExecutorType();

    alert("Set default executor: " + customDefaultExecutor);

    // Set the executor back to the system default. This is 
    // to allow the WebRequest script to run.
    executor = "Sys.Net.XMLHttpExecutor";
    Sys.Net.WebRequestManager.set_defaultExecutorType(
    sysDefaultExecutor);    

}


// Gets and sets the default timeout.
function DefaultTimeout()
{
    // Clear the previous results. 
    resultElement.innerHTML = "";

    // Get system default timeout.
    var sysDefaultTimeout = 
        Sys.Net.WebRequestManager.get_defaultTimeout();

    alert("Get default timeout: " + sysDefaultTimeout);


    // Set custom default timeout.
    Sys.Net.WebRequestManager.set_defaultTimeout(100);

    var customDefaultTimeout = 
        Sys.Net.WebRequestManager.get_defaultTimeout();

    alert("Set default timeout: " + customDefaultTimeout);


    // Set the timeout back to the system default. 
    Sys.Net.WebRequestManager.set_defaultTimeout(
    sysDefaultTimeout);    

}


// The On_InvokingRequest can be used to perform
// processing prior to the Web request being executed. 
function On_InvokingRequest(executor, eventArgs)
{
    alert("Executing OnInvokingRequest handler, before the Web request.");

    // Add custom code to perform processing prior
    // to the request being executed or to abort the 
    // request.
    alert("The current executor is: " + 
        executor.get_defaultExecutorType());

    // Use the eventArgs of type
    // NetworkRequestEventArgs to access the 
    // current WebRequest instance.
    var currentRequest = eventArgs.get_webRequest();
    var requestUrl = currentRequest.getResolvedUrl();           
    alert("Current request URL: " + requestUrl);
}

// The On_WebRequestComplete occurs after the
// Web request has returned, and can be used to
// get error status, process returned data, etc...
function On_WebRequestCompleted(executor, eventArgs) 
{

    if(executor.get_responseAvailable()) 
    {

        // Clear the previous results. 
        resultElement.innerHTML = "";

        // Display Web request status.                 
        resultElement.innerHTML  +=
          "Status: [" + executor.get_statusCode() + " " + 
                    executor.get_statusText() + "]" + "<br/>";

        // Display Web request headers.
        resultElement.innerHTML  += 
            "Headers: ";
        resultElement.innerHTML  += 
            executor.getAllResponseHeaders() + "<br/>";

        // Display Web request body.
        resultElement.innerHTML += 
            "Body: ";

        resultElement.innerHTML  += 
           executor.get_responseData();

    }

}

请参见

参考

Sys.Net.WebRequestExecutor 类

Sys.Net.XMLHttpExecutor 类

Sys.Net.WebRequest 类