发布excel对象

Question

我有以下代码来格式化我得到的excel文件并将它们保存为modified.xlsx

public void FormatFile()
{  
FileName = Convert.ToString("test.xlsx");
            SourceFileLocation = ("C:\Test");

            SourceFileName = Path.Combine(SourceFileLocation, FileName);
            saveLoc = Path.Combine(SourceFileLocation, "ModifiedExcel.xlsx");


            var excel = new Excel.Application();
            var workbook = excel.Workbooks.Open(SourceFileName);
            //var sheet = (Excel.Worksheet)workbook.Worksheets.Item[1]; // 1 is the first item, this is NOT a zero-based collection
            try
            {
                foreach (Excel.Worksheet tempSheet in workbook.Worksheets)
                {
                    if (((Excel.Worksheet)(tempSheet)).Name.Contains("Sheet1"))
                    {
                        if (File.Exists(saveLoc))
                        {
                            File.Delete(saveLoc);
                        }
                        tempSheet.Select();
                        workbook.SaveAs(saveLoc);
                    }

                    System.Runtime.InteropServices.Marshal.ReleaseComObject(tempSheet);
                }

                workbook.Save();
                workbook.Close();
                excel.Quit();

                System.Runtime.InteropServices.Marshal.ReleaseComObject(workbook);
                System.Runtime.InteropServices.Marshal.ReleaseComObject(excel);
            }
            catch(Exception)
            {
                System.Runtime.InteropServices.Marshal.ReleaseComObject(workbook);
                System.Runtime.InteropServices.Marshal.ReleaseComObject(excel);
            }

我发布了excel对象但是当我检查我的任务管理器时，我仍然可以看到excel进程正在运行。如果我多次运行此代码，则会创建许多进程。我没有正确发布excel对象吗？