正确关闭C# Excel COM对象

Question

我正在尝试正确关闭Excel COM对象，如Excel应用程序工作簿和工作表。我已经浏览了该网站和其他网站上的所有解决方案，但都无法解决问题。唯一的方法是运行循环以杀死或终止Excel进程。是否有更好的方法或仅终止单个Excel文件进程的方法？

        #region VARIABLE

            int nColumn = 0;
            int nIMPORT = 1;
            int endofsheet = 0;

            string IMPORTfilepath = null;
            string nsheet = null;
            string nCell = null;
            string lastfilename = "";            

            double rRFDS = 0;
            double cRFDS = 0;

            List<String> filename = new List<String>();  

            object misValue1 = System.Reflection.Missing.Value;

            //Opening Central DB
            Excel.Application CentralDB;
            Excel.Workbook CentralDBWorkBook;
            Excel.Worksheet CentralDBWorkSheet;
            Excel.Range CentralDBrange;

            //Opening RFDS
            Excel.Application IMPORT;
            Excel.Workbook IMPORTWorkBook;
            Excel.Worksheet IMPORTWorkSheet;

            //Excel.Range RFDSrange;
            Excel.Range CellAddress;

        #endregion

        CentralDB = new Microsoft.Office.Interop.Excel.Application();
        CentralDBWorkBook = CentralDB.Workbooks.Open(Odl1.FileName, 0, false, 5, "", "", true, Microsoft.Office.Interop.Excel.XlPlatform.xlWindows, "\t", false, false, 0, true, 1, 0);
        CentralDBWorkSheet = CentralDB.Worksheets.get_Item(1);

        IMPORT = new Microsoft.Office.Interop.Excel.Application();
        IMPORTfilepath = Odl2.FileNames[nIMPORT];
        IMPORTWorkBook = IMPORT.Workbooks.Open(IMPORTfilepath, 0, true, 5, "", "", true, Microsoft.Office.Interop.Excel.XlPlatform.xlWindows, "\t", false, false, 0, true, 1, 0);
        IMPORTWorkSheet = IMPORT.Worksheets.get_Item(1);

        CentralDBrange = CentralDBWorkSheet.UsedRange;        

        filename = Odl2.FileNames.ToList();

        endofsheet = CentralDBrange.Rows.Count;            

        foreach(string fn in filename)
        {
            try
            {
                IMPORTWorkBook = IMPORT.Workbooks.Open(fn, 0, true, 5, "", "", true, Microsoft.Office.Interop.Excel.XlPlatform.xlWindows, "\t", false, false, 0, true, 1, 0);
                CentralDBWorkSheet.Cells[nIMPORT + endofsheet, 1] = IMPORTWorkBook.Name;
                for (nColumn = 3; nColumn <= CentralDBrange.Columns.Count; nColumn++)
                {
                    nsheet = (string)(CentralDBrange.Cells[2, nColumn].Value2);
                    foreach (Excel.Worksheet ws in IMPORTWorkBook.Sheets)
                    {
                        if (ws.Name.Equals(nsheet))
                        {
                            IMPORTWorkSheet = IMPORTWorkBook.Worksheets.get_Item(nsheet);

                            nCell = (string)(CentralDBrange.Cells[3, nColumn].Value2);
                            CellAddress = CentralDBWorkSheet.get_Range(nCell, nCell);

                            rRFDS = CellAddress.Row;
                            cRFDS = CellAddress.Column;
                            CentralDBWorkSheet.Cells[nIMPORT + endofsheet, nColumn] = IMPORTWorkSheet.Cells[rRFDS, cRFDS];
                            label4.Text = nIMPORT.ToString() + "/" + Convert.ToString(Odl2.FileNames.Count());
                        }
                    }
                }
                nIMPORT++;
                nColumn = 3;
                CentralDBWorkBook.Save();
                IMPORTWorkBook.Close(false, null, null);
            }
            catch (System.Exception ex)
            {
                MessageBox.Show("Unable to release the Object " + ex.ToString());                            
            }
            lastfilename = fn;
        }

        CentralDB.Quit();
        releaseObject(CentralDBWorkSheet);
        releaseObject(CentralDBWorkBook);
        releaseObject(CentralDB);

        IMPORT.Quit();
        releaseObject(IMPORTWorkSheet);
        releaseObject(IMPORTWorkBook);
        releaseObject(IMPORT);
        GC.Collect();  
 }        

            private void releaseObject(object obj)
            {
                try
                {
                    System.Runtime.InteropServices.Marshal.ReleaseComObject(obj);
                    obj = null;
                }
                catch (System.Exception ex)
                {
                    obj = null;
                    MessageBox.Show("Unable to release the Object " + ex.ToString());
                }
                finally
                {
                    GC.Collect();
                }

            }

- Yousuf Hossain

---

也许这个之前的问题可以帮到你。 - elvin

提示：尽量少使用对Excel的引用，并且不要将其存储在本地/临时变量中。我还会考虑为Excel实例创建一个Singleton模式。 - Ahmed ilyas

Answer 1

尝试使用以下顺序（加上 .Visible = false）：

    releaseObject(CentralDBWorkSheet);
    releaseObject(CentralDBWorkBook);

    releaseObject(IMPORTWorkSheet);
    releaseObject(IMPORTWorkBook);

    CentralDB.Visible = false;
    IMPORT.Visible = false;

    CentralDB.Quit();
    IMPORT.Quit();

    releaseObject(CentralDB);
    releaseObject(IMPORT);

- noseratio - open to work

---

没有运用那个命令的好运。 - Yousuf Hossain

Answer 2

除了我的评论之外... 我使用这个方法，效果非常好...但是，我没有参考文献。

private void DoReleaseCOMObject(object obj)
        {
            int refCounter = Marshal.ReleaseComObject(obj);
            while (refCounter > 0)
            {
                refCounter = Marshal.ReleaseComObject(obj);
                System.Diagnostics.Debug.WriteLine("ReleaseCOM ref: " + refCounter);
            }

            obj = null;
        }

 private void DoFinalReleaseCOMObject(object obj)
        {
            int refCounter = Marshal.FinalReleaseComObject(obj);
            System.Diagnostics.Debug.WriteLine("FinalReleaseComObject ref: " + refCounter);

            obj = null;
        }

public void Dispose()
        {
            System.Diagnostics.Debug.WriteLine("In Dispose");
            this.Dispose(false); // because we are doing unmanaged
            GC.Collect();
            GC.SuppressFinalize(this);
        }

        protected virtual void Dispose(bool disposing)
        {
            System.Diagnostics.Debug.WriteLine("In Dispose (" + disposing + ")");
            if (!disposing) // unmanaged
            {
                #region COM Cleanup

                this.DoFinalReleaseCOMObject(this.headerStartCell);
                this.DoFinalReleaseCOMObject(this.headerEndCell);
                this.DoFinalReleaseCOMObject(this.headerWriteRange);

                this.DoFinalReleaseCOMObject(this.startCell);
                this.DoFinalReleaseCOMObject(this.endCell);
                this.DoFinalReleaseCOMObject(this.writeRange);

                this.DoFinalReleaseCOMObject(this.ws);
                this.DoFinalReleaseCOMObject(this.wb);
                this.DoFinalReleaseCOMObject(this.wbs);

                this.DoFinalReleaseCOMObject(this.excelApp);

                System.Diagnostics.Debug.WriteLine("I've tried to clean");

                #endregion
            }

            // no need for else condition if dispose is true as we are not dealing with managed objects
        }

是的，我实现了IDisposable接口。我还全局引用/保留了一些Excel对象的引用（相同实例），这就是我在退出Excel时要清理的内容。

- Ahmed ilyas