Question

I have code written in C# on a Windows7 and VS2010, 32 bit using .Net 3.5 and it is runing without any problem, now I converted it to 64 bit using .Net 4.0 but I got an error when my code call CloseHandle.

ERROR – CloseHandle
System.Runtime.InteropServices.SEHException (0x80004005): External component has thrown an exception.

unsafe
{
    fixed (byte* p = readBuffer)
    {
         IntPtr intPtr = (IntPtr)p;
         this.ReadFile(ref sourceFile, (ulong)buffer_size, intPtr, ref nNumBytesRead);

         if (intPtr != IntPtr.Zero)
         {
             try
             {
                 FunctionSqudf.CloseHandle(intPtr);
             }
             catch (Exception ex)
             {
                  Hardware.LogHardware.Error("CloseHandle", ex);
             }
         }
      }
  }


    [SecuritySafeCritical]
    [DllImport("kernel32", CharSet = CharSet.Ansi, SetLastError = true, ExactSpelling = true)]
    [return: MarshalAs(UnmanagedType.Bool)]
    internal static extern bool CloseHandle(IntPtr hObject);

Any help is appreciated.

Answer 1

You can’t use CloseHandle with a pointer to user memory. You need to allocate a HANDLE in order to close it. What do you expect CloseHandle to close?