为什么从客户端调用PageMethod时会创建页面实例?

时间:2011-08-04 11:46:06

标签: asp.net pagemethods

由于ASP.NET中的PageMethods需要是静态方法并标记为Web方法,我的印象是在调用页面方法时不会创建该特定页面的实例。

但是当我尝试在构造函数中设置一个断点时,每次调用pagemethod时都会遇到它。有人可以告诉我构建实例需要什么吗?

由于

服务器端

public partial class PageMethod : System.Web.UI.Page
{

    public PageMethod()
    {

    }

    [System.Web.Services.WebMethod()]
    public static string GetMessage()
    {
        return "Page Method Call";
    }
}

客户端(使用JQuery)

$.ajax({ type: 'POST',
                url: /PageMethod.aspx/GetMessage,
                data: null,
                success: onSuccess,
                contentType: "application/json; charset=utf-8",
                dataType: 'JSON',
                error: onError      
            });

1 个答案:

答案 0 :(得分:2)

修改

确实是构造函数!请参阅pagemeack的callmeack:

PageMethodTest_WebApplication3.DLL!PageMethodTest_WebApplication3._Default._Default() Line 9    C#
  App_Web_iielssqo.dll!ASP.default_aspx.default_aspx() + 0x43 bytes C#
  App_Web_iielssqo.dll!__ASP.FastObjectFactory_app_web_iielssqo.Create_ASP_default_aspx() + 0x43 bytes  C#
  System.Web.dll!System.Web.Compilation.BuildResultCompiledType.CreateInstance() + 0x21 bytes   
  System.Web.dll!System.Web.Compilation.BuildManager.CreateInstanceFromVirtualPath(System.Web.VirtualPath virtualPath, System.Type requiredBaseType, System.Web.HttpContext context, bool allowCrossApp, bool noAssert) + 0x78 bytes    
  System.Web.dll!System.Web.UI.PageHandlerFactory.GetHandlerHelper(System.Web.HttpContext context, string requestType, System.Web.VirtualPath virtualPath = {/Default.aspx}, string physicalPath) + 0x22 bytes  
  System.Web.dll!System.Web.UI.PageHandlerFactory.System.Web.IHttpHandlerFactory2.GetHandler(System.Web.HttpContext context, string requestType, System.Web.VirtualPath virtualPath, string physicalPath) + 0x29 bytes  
  System.Web.dll!System.Web.HttpApplication.MapHttpHandler(System.Web.HttpContext context, string requestType, System.Web.VirtualPath path, string pathTranslated = "C:\\Documents and Settings\\Administrator\\My Documents\\Visual Studio 2008\\Projects\\PageMethodTest_WebApplication3\\PageMethodTest_WebApplication3\\Default.aspx", bool useAppConfig) + 0xa1 bytes  

ASP.NET引擎将请求从pagemethod路由到aspx-handler-factory(PageHandlerFactory)。据我所知,这是ASP.NET的内在逻辑。因此,这是正确的:)

现在检查asmx-webmethod call:

  PageMethodTest_WebApplication3.DLL!PageMethodTest_WebApplication3.WebService1.HelloWorld() Line 22    C#
  [Native to Managed Transition]    
  [Managed to Native Transition]    
  System.Web.Extensions.dll!System.Web.Script.Services.WebServiceMethodData.CallMethod(object target, System.Collections.Generic.IDictionary<string,object> parameters) + 0x15c bytes   
  System.Web.Extensions.dll!System.Web.Script.Services.WebServiceMethodData.CallMethodFromRawParams(object target, System.Collections.Generic.IDictionary<string,object> parameters) + 0x1f bytes   
  System.Web.Extensions.dll!System.Web.Script.Services.RestHandler.InvokeMethod(System.Web.HttpContext context = {System.Web.HttpContext}, System.Web.Script.Services.WebServiceMethodData methodData = {System.Web.Script.Services.WebServiceMethodData}, System.Collections.Generic.IDictionary<string,object> rawParams) + 0x61 bytes    
  System.Web.Extensions.dll!System.Web.Script.Services.RestHandler.ExecuteWebServiceCall(System.Web.HttpContext context = {System.Web.HttpContext}, System.Web.Script.Services.WebServiceMethodData methodData) + 0x55 bytes    
  System.Web.Extensions.dll!System.Web.Script.Services.RestHandler.ProcessRequest(System.Web.HttpContext context) + 0xc bytes   
  System.Web.Extensions.dll!System.Web.Script.Services.ScriptHandlerFactory.HandlerWrapper.ProcessRequest(System.Web.HttpContext context) + 0xe bytes   
  System.Web.dll!System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() + 0xb6 bytes   

这里使用另一个httphandler-factory - ScriptHandlerFactory。

PS Moorthy,谢谢!好问题:)'生活和学习!'


静态 / [ WebMethod ] - cos页面方法仅由ajax调用(不创建页面)。

如果你想拥有Page实例,你应该使用UpdatePanel或AJAX.NET控件(例如DevExpressAjaxToolKit)。