今天在一个项目中使用Dcom的方式获取数据，但是发现Excel进程有时候能杀死，有时候杀不死，导致上传文件时出错的偶发性BUG，经过多次测试，调用API的方式可以彻底杀死Excel进程的方法！
方法体：
[DllImport("User32.dll", CharSet = CharSet.Auto)]
public static extern int GetWindowThreadProcessId(IntPtr hwnd, out int ID);
public static void KillExcel(Excel.Application excel)
{
IntPtr t = new IntPtr(excel.Hwnd); //得到这个句柄，具体作用是得到这块内存入口
int k = 0;
GetWindowThreadProcessId(t, out k); //得到本进程唯一标志k
System.Diagnostics.Process p = System.Diagnostics.Process.GetProcessById(k); //得到对进程k的引用
p.Kill(); //关闭进程k
}
方法调用：
Excel.Application app = null;
Excel.Workbook workBook = null;
Excel.Worksheet workSheet = null;
object Missing = Type.Missing;
app = new Excel.ApplicationClass();
app.Workbooks.Close();
app.Workbooks.Open(fileName, Missing, Missing, Missing, Missing, Missing, Missing, Missing, Missing, Missing, Missing,
Missing, Missing, Missing, Missing);
workBook = app.Workbooks[1] as Excel.Workbook;
workSheet = workBook.Worksheets[1] as Excel.Worksheet;
…………
workBook.Close(false, fileName, Missing);//关闭worksheet
app.Workbooks.Close();//关闭workbook
Marshal.ReleaseComObject(workBook);
app.Quit();
KillExcel(app);//彻底杀死Excel进程！
