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How I can clean the temporary Files in Visual Studio 2012 and how I can locate NullReferenceException in my project WebForms?

1 solution

you have two questions.

Q1: How do I clear the %tmp% folder in VS 2012?

Answer: VS 2012 has no temporary files that you can delete. You might have some being created by your program but that would be in VB.Net or C#. You have not told us which. Either way, you shouldn't.

The point of the %tmp% folder is that the files will only exist as long as they need to. As soon as the var that uses the file goes out-of-scope, then the GC will clean it up for you on the next pass.

Why do you ask? Are you having problems with temp files?

Q2: How do I locate a NullReferenceException?
There should be a Stack Trace with the error. This should tell you where the exception occurred, but it does not tell you what item was null. Usually it's obvious but sometimes it a little more obscure. I suggest you use the stack-track to locate the likely null candidate and add some error checking beforhand.

For example:


//instead of
return somemethod().ToString();

//handle the error before it can occur
var myvar = somemethod();
  return null;
return myvar.ToString();

This is how I handle any possible null value.
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Member 11765235 15-Jun-15 6:29am    
this is the stack trace of my error:

[NullReferenceException: Object reference not set to an instance of an object.]
DBAccess.setConnString() +77
DBAccess..ctor() +140
_Default..ctor() +49
ASP.default_aspx..ctor() in c:\Users\DELL\AppData\Local\Temp\Temporary ASP.NET Files\root\7b316ac0\74a3eae4\App_Web_default.aspx.cdcab7d2.rcv9xm8p.0.cs:0
__ASP.FastObjectFactory_app_web_default_aspx_cdcab7d2_rcv9xm8p.Create_ASP_default_aspx() in c:\Users\DELL\AppData\Local\Temp\Temporary ASP.NET Files\root\7b316ac0\74a3eae4\App_Web_default.aspx.cdcab7d2.rcv9xm8p.1.cs:0
System.Web.Compilation.BuildResultCompiledType.CreateInstance() +30
System.Web.Compilation.BuildManager.CreateInstanceFromVirtualPath(VirtualPath virtualPath, Type requiredBaseType, HttpContext context, Boolean allowCrossApp) +100
System.Web.UI.PageHandlerFactory.GetHandlerHelper(HttpContext context, String requestType, VirtualPath virtualPath, String physicalPath) +31
System.Web.UI.PageHandlerFactory.GetHandler(HttpContext context, String requestType, String virtualPath, String path) +37
System.Web.MaterializeHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +346
System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +155
Andy Lanng 15-Jun-15 6:32am    
ok - your error is in DBAccess.setConnString() (line 77)

Post that line and I'll see if I can tell what the error is

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