从内存中正确释放Excel

Question

我正在使用C＃＆amp; VS2013和VSTO。我的代码执行完美，但我遇到的一个问题是，当我转到任务管理器并查看详细信息时，Excel仍显示为运行，即使之后，我觉得我已经正确清理了。

这是我用来清理和关闭对Excel的所有引用的语法。只是引用Excel＆amp; VSTO，我遗漏了做腿部工作的肉和肉汁，或者这篇文章很长。

我是否有不正确的设置？为什么Excel仍显示在任务管理器中？

namespace ReleaseExcel
{
  public partial class Form12 : Form12
  {
    public static Excel.Worksheet newSeet;
    public static Excel._Worksheet currentsheet;
    public static Excel._Workbook oWB;
    public static Excel.Application xlApp;
    public static Excel.Workbook xlWorkBook;
    public static Excel.Worksheet xlWorkSheet;
    public static Excel.Workbook activeworkbook;

    public Form1()
    {
      InitializeComponents();
    }
    private void DoThis()
    {
        //Showing Declerations to Excel
        xlApp = new Excel.Application();
        xlWorkBook = xlApp.Workbooks.Add(misValue);
        xlWorkSheet = (Excel.Worksheet)xlWorkBook.Worksheets.get_Item(1);

        //Do some more stuff here

        //Showing a few more Declerations to Excel
        currentsheet = (Excel._Worksheet)(xlWorkBook.ActiveSheet);
        Excel.Range last = currentsheet.Cells.SpecialCells(Excel.XlCellType.xlCellTypeLastCell, Type.Missing);

        //Do a bit more stuff
        ClearExcel();
        while (System.Runtime.InteropServices.Marshal.ReleaseComObject(xlWorkSheet) != 0) { }
        while (System.Runtime.InteropServices.Marshal.ReleaseComObject(currentsheet) != 0) { }
        while (System.Runtime.InteropServices.Marshal.ReleaseComObject(xlWorkBook) != 0) { }
        while (System.Runtime.InteropServices.Marshal.ReleaseComObject(xlApp) != 0) { }
    }
    private static void ClearExcel()
    {
        GC.Collect();
        GC.WaitForPendingFinalizers();
    }      
  }
}

修改
我添加了GC.Collect()＆amp; GC.WaitForPendingFinalizers()但现在我的语法挂起了

while (System.Runtime.InteropServices.Marshal.ReleaseComObject(xlWorkBook) != 0) { }

现在已经坐在这条线上大约5分钟了，是什么导致了冻结？

编辑＃2
仍然没有这样的运气。这是代码

namespace ReleaseExcel
{
   public partial class Form12 : Form12
  {
    public static Excel.Worksheet newSeet;
    public static Excel._Worksheet currentsheet;
    public static Excel._Workbook oWB;
    public static Excel.Application xlApp;
    public static Excel.Workbook xlWorkBook;
    public static Excel.Worksheet xlWorkSheet;
    public static Excel.Workbook activeworkbook;

    public Form1()
    {
      InitializeComponents();
    }

    public void btnPush_Click(object sender, EventArgs e)
    {
        DoThis();
        GC.Collect();
        GC.WaitForPendingFinalizers();
    }
    private void DoThis()
    {
      //Showing Declerations to Excel
      xlApp = new Excel.Application();
      xlWorkBook = xlApp.Workbooks.Add(misValue);
      xlWorkSheet = (Excel.Worksheet)xlWorkBook.Worksheets.get_Item(1);

      //Do some more stuff here

      //Showing a few more Declerations to Excel
      currentsheet = (Excel._Worksheet)(xlWorkBook.ActiveSheet);
      Excel.Range last = currentsheet.Cells.SpecialCells(Excel.XlCellType.xlCellTypeLastCell, Type.Missing);

    }
  }
}