DataGridView导出到Excel，当前页，所有页

首先，DataGridView使用的分页为自定义分页，也就是所谓的真分页。

大概思路就是，新建一个Excel的对象，循环遍历DataGridview的列头，然后在循环遍历每个单元。

导出所有页，可以现在所有的数据保存到一个临时的table中，然后，循环遍历这个table就行

代码如下：

/// <summary>   
        ///方法，导出DataGridView中的数据到Excel文件   
        /// </summary>   
        /// <remarks>  
        /// add com "Microsoft Excel 11.0 Object Library"  
        /// using Excel=Microsoft.Office.Interop.Excel;  
        /// using System.Reflection;  
        /// </remarks>  
        /// <param name= "dgv"> DataGridView </param>   
        public void DataGridViewToExcel(DataGridView dgv)
        {
            #region   验证可操作性
            //申明保存对话框   
            SaveFileDialog dlg = new SaveFileDialog();
            //默然文件后缀   
            dlg.DefaultExt = "xls ";
            //以当前时间作为默认文件名
            dlg.FileName = DateTime.Now.ToString("yyyymmddhhmmss") + "CustomerData";
            //文件后缀列表   
            dlg.Filter = "EXCEL文件(*.XLS)|*.xls ";
            //默然路径是系统当前路径   
            dlg.InitialDirectory = Directory.GetCurrentDirectory();
            //打开保存对话框   
            if (dlg.ShowDialog() == DialogResult.Cancel) return;
            //返回文件路径   
            string fileNameString = dlg.FileName;
            //验证strFileName是否为空或值无效   
            if (fileNameString.Trim() == " ")
            { return; }
            //定义表格内数据的行数和列数   
            int rowscount = dgv.Rows.Count;
            int colscount = dgv.Columns.Count;
            //行数必须大于0   
            if (rowscount <= 0)
            {
                MessageBox.Show("没有数据可供保存 ", "提示 ", MessageBoxButtons.OK, MessageBoxIcon.Information);
                return;
            }

            //列数必须大于0   
            if (colscount <= 0)
            {
                MessageBox.Show("没有数据可供保存 ", "提示 ", MessageBoxButtons.OK, MessageBoxIcon.Information);
                return;
            }

            //行数不可以大于65536   
            if (rowscount > 65536)
            {
                MessageBox.Show("数据记录数太多(最多不能超过65536条)，不能保存 ", "提示 ", MessageBoxButtons.OK, MessageBoxIcon.Information);
                return;
            }

            //列数不可以大于255   
            if (colscount > 255)
            {
                MessageBox.Show("数据记录行数太多，不能保存 ", "提示 ", MessageBoxButtons.OK, MessageBoxIcon.Information);
                return;
            }

            //验证以fileNameString命名的文件是否存在，如果存在删除它   
            FileInfo file = new FileInfo(fileNameString);
            if (file.Exists)
            {
                try
                {
                    file.Delete();
                }
                catch (Exception error)
                {
                    MessageBox.Show(error.Message, "删除失败 ", MessageBoxButtons.OK, MessageBoxIcon.Warning);
                    return;
                }
            }
            #endregion
            Microsoft.Office.Interop.Excel.Application objExcel = null;
            Microsoft.Office.Interop.Excel.Workbook objWorkbook = null;
            Microsoft.Office.Interop.Excel.Worksheet objsheet = null;
            try
            {
                //申明对象   
                objExcel = new Microsoft.Office.Interop.Excel.Application();
                objWorkbook = objExcel.Workbooks.Add(Missing.Value);
                objsheet = (Microsoft.Office.Interop.Excel.Worksheet)objWorkbook.ActiveSheet;
                //设置EXCEL不可见   
                objExcel.Visible = false;

                //向Excel中写入表格的表头   
                int displayColumnsCount = 1;
                for (int i = 0; i <= dgv.ColumnCount - 1; i++)
                {
                    if (dgv.Columns[i].Visible == true)
                    {
                        objExcel.Cells[1, displayColumnsCount] = dgv.Columns[i].HeaderText.Trim();
                        displayColumnsCount++;
                    }
                }
                //向Excel中逐行逐列写入表格中的数据   
                for (int row = 0; row <= dgv.RowCount - 1; row++)
                {
                    displayColumnsCount = 1;
                    for (int col = 0; col < colscount; col++)
                    {
                        if (dgv.Columns[col].Visible == true)
                        {
                            try
                            {
                                if (dgv.Rows[row].Cells[col].Value != null)
                                {
                                    objExcel.Cells[row + 2, displayColumnsCount] = "'" + dgv.Rows[row].Cells[col].Value.ToString();
                                }
                                else
                                {
                                    objExcel.Cells[row + 2, displayColumnsCount] = "";
                                }
                                displayColumnsCount++;
                            }
                            catch (Exception)
                            {

                            }

                        }
                    }
                }

                //保存文件   
                objWorkbook.SaveAs(fileNameString, Missing.Value, Missing.Value, Missing.Value, Missing.Value,
                        Missing.Value, Microsoft.Office.Interop.Excel.XlSaveAsAccessMode.xlShared, Missing.Value, Missing.Value, Missing.Value,
                        Missing.Value, Missing.Value);
            }
            catch (Exception error)
            {
                MessageBox.Show(error.Message, "警告 ", MessageBoxButtons.OK, MessageBoxIcon.Warning);
                return;
            }
            finally
            {
                //关闭Excel应用   
                if (objWorkbook != null) objWorkbook.Close(Missing.Value, Missing.Value, Missing.Value);
                if (objExcel.Workbooks != null) objExcel.Workbooks.Close();
                if (objExcel != null) objExcel.Quit();

                objsheet = null;
                objWorkbook = null;
                objExcel = null;
            }
            MessageBox.Show(fileNameString + "\n\n导出完毕! ", "提示 ", MessageBoxButtons.OK, MessageBoxIcon.Information);

        }

        #endregion