无法使用Interopservices关闭excel

using System.Runtime.InteropServices;
using Excel = Microsoft.Office.Interop.Excel;

// 创建Excel对象
Excel.Application excelApp = new Excel.Application();
Excel.Workbook workbook = excelApp.Workbooks.Add();
Excel.Worksheet worksheet = workbook.ActiveSheet;

// 使用Excel对象进行操作

// 释放Excel对象
Marshal.ReleaseComObject(worksheet);
Marshal.ReleaseComObject(workbook);
Marshal.ReleaseComObject(excelApp);

// 关闭Excel进程
excelApp.Quit();

using Excel = Microsoft.Office.Interop.Excel;

Excel.Application excelApp = new Excel.Application();
Excel.Workbook workbook = null;
Excel.Worksheet worksheet = null;

try
{
    // 创建Excel对象
    workbook = excelApp.Workbooks.Add();
    worksheet = workbook.ActiveSheet;

    // 使用Excel对象进行操作
}
catch (Exception ex)
{
    // 处理异常
}
finally
{
    // 释放Excel对象
    if (worksheet != null)
    {
        Marshal.ReleaseComObject(worksheet);
    }
    if (workbook != null)
    {
        Marshal.ReleaseComObject(workbook);
    }
    if (excelApp != null)
    {
        excelApp.Quit();
        Marshal.ReleaseComObject(excelApp);
    }
}

using System.Runtime.InteropServices;
using Excel = Microsoft.Office.Interop.Excel;

Excel.Application excelApp = new Excel.Application();
Excel.Workbook workbook = excelApp.Workbooks.Add();
Excel.Worksheet worksheet = workbook.ActiveSheet;

// 使用Excel对象进行操作

// 释放Excel对象
Marshal.ReleaseComObject(worksheet);
Marshal.ReleaseComObject(workbook);
Marshal.ReleaseComObject(excelApp);

// 执行垃圾回收
GC.Collect();
GC.WaitForPendingFinalizers();

// 关闭Excel进程
excelApp.Quit();