System.Runtime.InteropServices.Marshal.ReleaseComObject(sheets);         System.Runtime.InteropServices.Marshal.ReleaseComObject(worksheet);         System.Runtime.InteropServices.Marshal.ReleaseComObject(excelApp);         System.Runtime.InteropServices.Marshal.ReleaseComObject(range);         excelApp = null;         wbclass = null;         sheets = null;         worksheet = null;         range = null;         GC.Collect();         GC.WaitForPendingFinalizers();

//调用底层函数获取进程标示     [DllImport("User32.dll")]     public static extern int GetWindowThreadProcessId(IntPtr hWnd, out int ProcessId);     private static void KillExcel(Microsoft.Office.Interop.Excel.Application theApp)     {         int id = 0;         IntPtr intptr = new IntPtr(theApp.Hwnd);         System.Diagnostics.Process p = null;         try         {             GetWindowThreadProcessId(intptr, out id);             p = System.Diagnostics.Process.GetProcessById(id);             if (p != null)             {                 p.Kill();                 p.Dispose();             }         }         catch (Exception ex)         {         }     }