开发基于Asp.Net的系统，最初使用R.a.d Treeview 2.5，经常会出现控件无法加载的情况。原以为是控件本身的问题，可后来将R.a.d Treeview升级到3.0版，还是无法解决。去Terelik官方网站看了F.A.Q，也没有提到这个问题。
后来发现，当出现控件无法加载的情况之后，只要Restart系统，或者等一会儿重新编译执行程序，控件无法加载的情况即消失了。难道是Framework的问题？怕我们编程太累，让我们中间休息一下？郁闷.......
今天偶然间发现如下一篇文章，照之做了之后，问题解决~哈
PRB: Access Denied Error When You Make Code Modifications with Index Services Running
http://support.microsoft.com/default.aspx?scid=kb;en-us;329065
CAUSE
If you run Index Server (Cisvc.exe), then Index Server may rescan the Temporary ASP.NET Files directory while it requests a Microsoft ASP.NET page. Cisvc.exe then holds a lock on the Temporary ASP.NET Files directory for one to five minutes. The length of time of the lock depends on the size of the directory that causes the Aspnet_wp.exeprocess (or W3wp.exe process for applications that run on Microsoft Internet Information Services [IIS] 6.0) to not load the particular DLL.
RESOLUTION
If you do not use Index Server on the server, you can disable it. To do so, follow these steps:
Click Start, and then click Services.
Locate Indexing Service from the list of services, and then click Indexing Service Properties from the subform.
On the General tab of the Indexing Service Properties dialog box, in the Startup type drop-down item list, click Disabled.
Click OK.
If you use Index Server, you can exclude the Temporary ASP.NET Files directory from the folders that the Index Server scans. To do so, follow these steps:
Click Start, point to All Programs, point to Administrative Tools, and then click Computer Management.
Expand the Services and Applications node, expand the Indexing Service node, and then expand the System node.
Right-click the Directories folder, point to New, and then click Directory from the subform to open the Add Directory dialog box.
Click Browse, and then locate the Temporary ASP.NET Files directory. You typically find the Temporary ASP.NET files in the following path: c:\Microsoft.NETFramework\Temporary ASP.NET Files
Note is the version of .NET Framework installed on your computer.
Click No under the Include in Index? option buttons.
Click OK to close.
Close the Computer Management dialog box.
Restart the Indexing Services service.
MORE INFORMATION
Other software that is designed to scan directories at regular intervals may lock the files that are located in the Temporary ASP.NET Files directory in a manner that is similar to how the Indexing Service locks the files. Examples of such software include virus scanners and backup software. Microsoft recommends that you see the manufacturers' manuals for the individual software for information about how to disable or to exclude the Temporary ASP.NET Files from these services.
原来是索引服务引起的故障～～