操作excel文件怎么在末尾追加？

Question

private void ExportToExcel(string FileName)
        {
            if (FileName.IndexOf(".") <= 0)
            {
                FileName = FileName + ".xls";
            }
            else
            {
                string[] str = FileName.Split('.');
                if (str.Length > 2)
                {
                    FileName = str[0] + str[str.Length - 1];
                }
            }
            Excel.Application app;
            try
            {
                app = new Excel.Application();
            }
            catch 
            {
             ClsCommFuncs.Alert("没有安装Excel程序或者安装错误");
                return;
            }
            app.Workbooks.Add(true);
            app.Visible = false;            Excel.Workbooks books = (Excel.Workbooks)app.Workbooks;
            Excel.Workbook book = (Excel.Workbook)books.Add(Type.Missing);            int iget = 1;
            int dwindex = 0;
            //写头
            if (panelHide1.Visible == true)
            {
                foreach (DataGridViewColumn datcol in dgvLog.Columns)
                {
                    app.Cells[iget, dwindex + 1] = datcol.HeaderText;
                    dwindex++;
                }
            }
            else
            {
                app.Cells[iget, 1] = dgvLog.Columns[0].HeaderText;
                app.Cells[iget, 2] = dgvLog.Columns[1].HeaderText;
                app.Cells[iget, 3] = dgvLog.Columns[2].HeaderText;
                app.Cells[iget, 4] = dgvLog.Columns[5].HeaderText;
            }            //写内容
            int nIndex = 0;
            foreach (TLogData t in m_tLogDataList)
            {
                iget++;                app.Cells[iget, 1] = (++nIndex).ToString();
                app.Cells[iget, 2] = t.GetTime();
                app.Cells[iget, 3] = t.GetLogType();
                if (panelHide1.Visible == true)
                {
                    app.Cells[iget, 4] = t.GetLogCategory();
                    app.Cells[iget, 5] = t.GetUserName();
                    app.Cells[iget, 6] = t.GetLogDecs();
                }
                else
                {
                    app.Cells[iget, 4] = t.GetLogDecs();
                }
            }            app.Cells.EntireColumn.AutoFit();            try
            {
                book.SaveAs(FileName, Type.Missing, Type.Missing, Type.Missing, 
                    Type.Missing, Type.Missing, Excel.XlSaveAsAccessMode.xlExclusive, 
                    Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing);            }
            catch
            {
                ClsCommFuncs.Alert("导出失败，确认文件没有打开或Excel安装成功");
            }            book.Close(false, Type.Missing, Type.Missing);
            books.Close();
            app.Quit();
            GC.Collect();
        }
其中写内容的这么一段需要不断的写，也就是m_tLogDataList会不断的更新 //写内容
            int nIndex = 0;
            foreach (TLogData t in m_tLogDataList)
            {
                iget++;                app.Cells[iget, 1] = (++nIndex).ToString();
                app.Cells[iget, 2] = t.GetTime();
                app.Cells[iget, 3] = t.GetLogType();
                if (panelHide1.Visible == true)
                {
                    app.Cells[iget, 4] = t.GetLogCategory();
                    app.Cells[iget, 5] = t.GetUserName();
                    app.Cells[iget, 6] = t.GetLogDecs();
                }
                else
                {
                    app.Cells[iget, 4] = t.GetLogDecs();
                }
            }
我尝试将首尾以及写内容的分成三个部分，这样写内容的那段就可以重复使用，可是总是报“因为应用程序正在发送一个输入同步呼叫,所以无法执行传出的呼叫”，这样的错误！
不知道怎么解决了，请各位帮忙看看！

Answer 1

还有，有办法在同一个excel文件尾部写数据么?

Answer 2

我是笨方法.
全部数据变成DataTable.追加完后.再变成Xls

Answer 3

每次写完记录下Cells[iget, 4] 
下次写时 从iget＋1开始写

Answer 4

m_tLogDataList会更新的，每次写完后，会通知服务器继续发送数据的，收到ACK后m_tLogDataList更新，继续导出，这样讲是不是明白了？

Answer 5

服务器一次发送给我15条，我都是保存在m_tLogDataList中的，然后一次性写到excel中。
你的方法我也想到了，可是每次运行到
“              app.Cells[iget, 1] = (++nIndex).ToString();”
就会报错“因为应用程序正在发送一个输入同步呼叫,所以无法执行传出的呼叫”

Answer 6

        Excel.Application m_ExcelApp = null;
        Excel.Workbooks books = null;
        Excel.Workbook book = null;
        private void OnCreateExcelApp()
        {
            if (m_ExportFileName.IndexOf(".") <= 0)
            {
                m_ExportFileName = m_ExportFileName + ".xls";
            }
            else
            {
                string[] str = m_ExportFileName.Split('.');
                if (str.Length > 2)
                {
                    m_ExportFileName = str[0] + str[str.Length - 1];
                }
            }            try
            {
                m_ExcelApp = new Excel.Application();
            }
            catch
            {
                ClsCommFuncs.Alert("没有安装Excel程序或者安装错误");
                return;
            }
            m_ExcelApp.Workbooks.Add(true);
            m_ExcelApp.Visible = false;            books = (Excel.Workbooks)m_ExcelApp.Workbooks;
            book = (Excel.Workbook)books.Add(Type.Missing);
            int dwindex = 0;
            //写头
            if (panelHide1.Visible == true)
            {
                foreach (DataGridViewColumn datcol in dgvLog.Columns)
                {
                    m_ExcelApp.Cells[1, dwindex + 1] = datcol.HeaderText;
                    dwindex++;
                }
            }
            else
            {
                m_ExcelApp.Cells[1, 1] = dgvLog.Columns[0].HeaderText;
                m_ExcelApp.Cells[1, 2] = dgvLog.Columns[1].HeaderText;
                m_ExcelApp.Cells[1, 3] = dgvLog.Columns[2].HeaderText;
                m_ExcelApp.Cells[1, 4] = dgvLog.Columns[5].HeaderText;
            }
        }
        int iget = 1;
        private bool OnExportToExcel()
        {
            //写内容
          
            int nIndex = 0;
            foreach (TLogData t in m_tLogDataList)
            {
                iget++;                m_ExcelApp.Cells[iget, 1] = (++nIndex).ToString();
                m_ExcelApp.Cells[iget, 2] = t.GetTime();
                m_ExcelApp.Cells[iget, 3] = t.GetLogType();
                if (panelHide1.Visible == true)
                {
                    m_ExcelApp.Cells[iget, 4] = t.GetLogCategory();
                    m_ExcelApp.Cells[iget, 5] = t.GetUserName();
                    m_ExcelApp.Cells[iget, 6] = t.GetLogDecs();
                }
                else
                {
                    m_ExcelApp.Cells[iget, 4] = t.GetLogDecs();
                }
            }
            m_ExcelApp.Cells.EntireColumn.AutoFit();
            return true;
        }
        private void OnCloseExcelApp()
        {
            if (book == null||books == null ||m_ExcelApp == null)
            {
                return;
            }
    
            try
            {
                book.SaveAs(m_ExportFileName, Type.Missing, Type.Missing, Type.Missing,
                    Type.Missing, Type.Missing, Excel.XlSaveAsAccessMode.xlExclusive,
                    Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing);
            }
            catch
            {
                ClsCommFuncs.Alert("导出失败，确认文件没有打开或Excel安装成功");
            }            book.Close(false, Type.Missing, Type.Missing);
            books.Close();
            m_ExcelApp.Quit();
            GC.Collect();
        }
这是我后来改写的代码！