C# 不断从AjaxControlToolkit获取错误

从AjaxControlToolkit获取以下错误。 如何解决

Could not load file or assembly 'System.Web' or one of its dependencies. The system cannot find the file specified. 
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. 

Exception Details: System.IO.FileNotFoundException: Could not load file or assembly 'System.Web' or one of its dependencies. The system cannot find the file specified.

Source Error: 

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.  

Assembly Load Trace: The following information can be helpful to determine why the assembly 'System.Web' could not be loaded.


WRN: Assembly binding logging is turned OFF.
To enable assembly bind failure logging, set the registry value [HKLM\Software\Microsoft\Fusion!EnableLog] (DWORD) to 1.
Note: There is some performance penalty associated with assembly bind failure logging.
To turn this feature off, remove the registry value [HKLM\Software\Microsoft\Fusion!EnableLog].


Stack Trace: 



    [FileNotFoundException: Could not load file or assembly 'System.Web' or one of its dependencies. The system cannot find the file specified.]
       System.Reflection.RuntimeAssembly._nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, RuntimeAssembly locationHint, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks) +0
       System.Reflection.RuntimeAssembly.nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, RuntimeAssembly locationHint, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks) +34
       System.Reflection.RuntimeAssembly.InternalLoadAssemblyName(AssemblyName assemblyRef, Evidence assemblySecurity, RuntimeAssembly reqAssembly, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks) +152
       System.Reflection.RuntimeAssembly.InternalLoad(String assemblyString, Evidence assemblySecurity, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean forIntrospection) +77
       System.Reflection.RuntimeAssembly.InternalLoad(String assemblyString, Evidence assemblySecurity, StackCrawlMark& stackMark, Boolean forIntrospection) +16
       System.Reflection.Assembly.Load(String assemblyString) +28
       AjaxControlToolkit.ScriptEntry.LoadAssembly() +27
       AjaxControlToolkit.ToolkitScriptManager.IsScriptCombinable(ScriptEntry scriptEntry) +25
       AjaxControlToolkit.ToolkitScriptManager.OnResolveScriptReference(ScriptReferenceEventArgs e) +277
       System.Web.UI.ScriptManager.RegisterScripts() +269
       System.Web.UI.ScriptManager.OnPagePreRenderComplete(Object sender, EventArgs e) +124
       System.Web.UI.Page.OnPreRenderComplete(EventArgs e) +121
       System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1155



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我的眼睛疼。在此阅读如何提问：添加更多信息。粘贴一些页面部分，configs，描述如何将ajaxcontroltoolkit添加到项目中。这是我的第一个问题，所以下次我将简要解释。我安装了NuGet软件包，然后从软件包中安装了AjaxControlToolkit。从CodePlex.com下载AjaxControlToolkit 4.5。已将.dll文件加载到工具栏。这是web.config中的配置文件，有人能帮我吗？被困在sthg-的中间-