excel 导出

        /// 

        /// 导出Excel方法：Excel导出模式，支持绑定下拉选择
        /// 
        /// 执行返回的消息，非空时执行失败
        /// 导出的数据
        /// 导出需要用到的自定义列名，如果为空，取数据源的表名
        /// 导出的文件名
        /// 哪一列需要绑定默认下拉值；字典Dictionary 类型，int是需要绑定的列；string是需要绑定的下拉，多个值用逗号隔开
        /// 
        public static bool OutputToExcel1(out string msg, System.Data.DataTable dt, string customColumnName = "", string ExportName = "", Dictionary dicDropdown = null)
        {
            bool result = true;
            msg = "";
            try
            {
                System.Windows.Forms.SaveFileDialog dlg = new System.Windows.Forms.SaveFileDialog();  //保存文件对话框
                dlg.Filter = "*.xls|*.xls";                 //过滤文件类型
                dlg.CreatePrompt = false;                   //提示创建文件
                dlg.FileName = ExportName;
                if (dlg.ShowDialog() == System.Windows.Forms.DialogResult.OK)
                {
                    Microsoft.Office.Interop.Excel.Application xlApp = new Microsoft.Office.Interop.Excel.Application();//表示Excel应用程序
                    if (xlApp == null)
                    {
                        msg = "可能您的机子未安装excel，无法创建excel对象！";
                        return false;
                    }
                    Workbooks workbooks = xlApp.Workbooks;  //workbook对象的集合
                    Workbook workbook = workbooks.Add(Microsoft.Office.Interop.Excel.XlWBATemplate.xlWBATWorksheet); //表示一个workbook
                    Worksheet worksheet = (Microsoft.Office.Interop.Excel.Worksheet)workbook.Worksheets[1]; //返回workbook的第一个worksheet 

                    Microsoft.Office.Interop.Excel.Range allRange = worksheet.Range[worksheet.Cells[1, 1], worksheet.Cells[1 + dt.Columns.Count, 1 + dt.Rows.Count]];
                    allRange.NumberFormatLocal = "@";//文本格式
                    allRange.EntireColumn.AutoFit(); //全部列自适应宽度
                    allRange.EntireRow.AutoFit();    //全部行自适应高度
                    allRange.HorizontalAlignment = Microsoft.Office.Interop.Excel.XlHAlign.xlHAlignCenter;//水平居中
                    allRange.VerticalAlignment = Microsoft.Office.Interop.Excel.XlVAlign.xlVAlignCenter; //垂直居中
                    

                    //设置下拉选择
                    if (dicDropdown != null)
                    {
                        foreach (var item in dicDropdown)
                        {
                            //设定一定范围内单元格的格式
                            Microsoft.Office.Interop.Excel.Range myrange = worksheet.Columns[item.Key]; //worksheet.Range[worksheet.Cells[2, i], worksheet.Cells[2 + i, i]];   //第二行开始，到记录总数
                            //worksheet.Cells[1, 1 + i] = titleList[i];//为单元格赋值
                            myrange.Validation.Modify(Microsoft.Office.Interop.Excel.XlDVType.xlValidateList, Microsoft.Office.Interop.Excel.XlDVAlertStyle.xlValidAlertStop, Type.Missing, item.Value, Type.Missing);
                        }
                    }

                    //设置标题
                    List titleList = customColumnName.Split(',').ToList();
                    for (int i = 0; i < titleList.Count; i++)
                    {
                        //设定一定范围内单元格的格式
                        Microsoft.Office.Interop.Excel.Range myrange = worksheet.Range[worksheet.Cells[1, 1 + i], worksheet.Cells[1, 1 + i]];
                        worksheet.Cells[1, 1 + i] = titleList[i];//为单元格赋值
                    }


                    //插入数据
                    for (int i = 0; i < dt.Rows.Count; i++)
                    {
                        for (int j = 0; j < dt.Columns.Count; j++)
                        {
                            //设定一定范围内单元格的格式
                            Microsoft.Office.Interop.Excel.Range myrange = worksheet.Range[worksheet.Cells[2 + i, 1 + j], worksheet.Cells[2 + i, 1 + j]];

                            worksheet.Cells[2 + i, 1 + j] = dt.Rows[i][j].ToString();//为单元格赋值
                        }
                    }
                    
                    //保存及退出
                    workbook.Saved = true;
                    workbook.SaveCopyAs(dlg.FileName);
                    xlApp.Quit();

                    GC.Collect();//强行销毁 
                    Process.Start(dlg.FileName); //打开EXCEL
                }
            }
            catch (Exception ex)
            {
                msg = ex.Message;
                result = false;
            }
            return result;
        }

        /// 

        /// 导出Excel方法：数据流方式，已文本方式导出
        /// 
        /// 导出的数据
        /// 导出需要用到的自定义列名，如果为空，取数据源的表名
        /// 导出的文件名
        /// 
        public static bool OutputToExcel2(System.Data.DataTable dt, string customColumnName = "", string ExportName = "")
        {
            //if (dt == null || dt.Rows.Count == 0) return false; 支持导出空模版
            bool flag = false;

            System.Windows.Forms.SaveFileDialog dlg = new System.Windows.Forms.SaveFileDialog();  //保存文件对话框
            dlg.Filter = "*.xls|*.xls";                 //过滤文件类型
            dlg.CreatePrompt = false;                   //提示创建文件
            dlg.FileName = ExportName;
            if (dlg.ShowDialog() == System.Windows.Forms.DialogResult.OK)
            {
                //获取流对象
                Stream myStream = dlg.OpenFile();
                //获取流写入器对象
                StreamWriter sw = new StreamWriter(myStream, System.Text.Encoding.GetEncoding(-0));
                string columnTitle = "";
                try
                {
                    //写入列标题 
                    if (customColumnName != "")
                    {
                        columnTitle = customColumnName.Replace(",", "\t");
                    }
                    else
                    {
                        for (int i = 0; i < dt.Columns.Count; i++)
                        {
                            if (i > 0)
                            {
                                columnTitle += "\t";
                            }
                            columnTitle += dt.Columns[i].ColumnName;
                        }
                    }
                    sw.WriteLine(columnTitle);
                    //写入列内容 
                    for (int j = 0; j < dt.Rows.Count; j++)
                    {
                        string columnValue = "";
                        for (int k = 0; k < dt.Columns.Count; k++)
                        {
                            if (k > 0)
                            {
                                columnValue += "\t";
                            }
                            if (dt.Rows[j][k] == null)
                                columnValue += "";
                            else
                                columnValue += dt.Rows[j][k].ToString().Trim();
                        }
                        sw.WriteLine(columnValue);
                    }
                    sw.Close();
                    myStream.Close();
                    flag = true;
                }
                catch (Exception ex)
                {
                    throw new Exception(ex.Message);
                }
                finally
                {
                    sw.Close();
                    myStream.Close();
                }
            }
            return flag;
        }