File replace in HttpPostedFileBase MVC3 - asp.net-mvc-3

Question

If the file is uploading with the name already in the specified path, it is showing error. I want to replace with the new file. I have placed the error and the code. Please help to replace the existing image.
Error: The process cannot access the file '' because it is being used by another process.
Code:
[HttpPost]
public ActionResult MyUpload(HttpPostedFileBase file)
{
string filePath = string.Empty;
string path = "C:\\";
string filePath = string.Empty;
try
{
if (file != null && file.ContentLength > 0)
{
filePath = path + file.FileName;
file.SaveAs(filePath);
file.InputStream.Dispose();
GC.Collect();
// other operations, where can occur an exception
// (because the uploaded file can have a bad content etc.)
}
}
catch (Exception e)
{
}
}

Answer 1

Based upon what you posted, I would suggest the following:
[HttpPost]
public ActionResult Foo(HttpPostedFileBase file)
{
var path = #"C:\";
var filename = file.FileName;
file.SaveAs(System.IO.Path.Combine(path, filename));
// do stuff here.
return RedirectToAction("Index");
}

Answer 2

I had this very same issue. I had a sub-folder called "files" where I uploaded files using file.SaveAs() ('file' being of type 'HttpPostedFileBase' [using MVC]). After some local investigation and online research, it turns out that an IIS worker thread/process was locking my file. At first I thought {HttpPostedFileBase}.SaveAs() was somehow locking my file. I even tried to (first) close, and then dispose the {HttpPostedFileBase}.InputStream, and that also didn't help. In the end, it wasn't even related to the file upload process at all. After uploading the file (a PDF), I processed it using ITextSharp, but forgot to dispose of the object wrapper (so it was probably sitting in the GC). Because of that, the next file upload failed due to the locked existing file. BTW, I also tried file.InputStream.Dispose(); file.InputStream.Close(); GC.Collect();, but removed them all in the end, and it still works perfectly now. Bottom line, if an IIS Worker process is locking your file, there's probably a good reason - something somewhere in your code you are missing, and it most likely isn't the MVC framework or IIS itself gone rogue. ;) Also, as it turns out, {HttpPostedFileBase}.SaveAs() WILL overwrite files if they exist, so there's no need to delete them first.
One other tip: I read somewhere to watch out who is creating the files based on how your authorization is setup (whether or not you using an IIS process identity, or the logged-in user identity). In some cases, a file may be created by one logged in user, who then becomes the owner, and another file of the same name from a different user may become blocked; might be something to keep in mind in special cases (like intranet based web apps).