datagridview导成excel很慢

Question

我是用for循环把datagridview中的数据一条一条导出到excel的，但是数据超过几千条就好慢，不知道有什么更好的方法

Answer 1

是不是只有用for循环导出数据

Answer 2

        /// <summary>
        /// 判断本机是否安装Excel文件方法
        /// </summary>
        /// <returns></returns>
        private static bool codeboolisExcelInstalled()
        {
            Type type = Type.GetTypeFromProgID("Excel.Application");
            return type != null;
        }/// <summary>
        /// 将DataGridView内容到非标准的Excel格式，默认工作表名与文件名相同 
        /// </summary>
        public static void ExportToNonstandardExcel(DataGridView myDGV)
        {
            if (codeboolisExcelInstalled())
            {
                if (GetEffectiveRows(myDGV) == 0)
                {
                    MessageBox.Show(" 没有数据可供导出！", "提示信息", MessageBoxButtons.OK, MessageBoxIcon.Information);
                    return;
                }
                else
                {
                    SaveFileDialog saveFileDialog = new SaveFileDialog();
                    saveFileDialog.DefaultExt = "xls";
                    saveFileDialog.Filter = "Microsoft Excel 97-2003 (*.xls)|*.xls|Microsoft Excel 2007-2010 (*.xlsx)|*.xlsx";
                    saveFileDialog.FilterIndex = 0;
                    saveFileDialog.RestoreDirectory = true;
                    saveFileDialog.CreatePrompt = false;//指示该文件不存在，是否提示用户创建
                    saveFileDialog.Title = "导出数据到Excel表格";
                    saveFileDialog.ShowDialog();
                    if (saveFileDialog.FileName.IndexOf(":") < 0) return; //被点了"取消"
                    Stream myStream;
                    myStream = saveFileDialog.OpenFile();
                    StreamWriter sw = new StreamWriter(myStream, System.Text.Encoding.GetEncoding(-0));
                    string columnTitle = "";
                    try
                    {
                        //写入列标题
                        for (int i = 0; i < myDGV.ColumnCount; i++)
                        {
                            if (i > 0)
                            {
                                columnTitle += "\t";
                            }
                            columnTitle += myDGV.Columns[i].HeaderText;
                        }
                        sw.WriteLine(columnTitle);                        //写入列内容
                        for (int j = 0; j < myDGV.Rows.Count; j++)
                        {
                            string columnValue = "";
                            for (int k = 0; k < myDGV.Columns.Count; k++)
                            {
                                if (k > 0)
                                {
                                    columnValue += "\t";
                                }
                                if (myDGV.Rows[j].Cells[k].Value == null)
                                {
                                    columnValue += "";
                                }
                                else
                                {
                                    columnValue += myDGV.Rows[j].Cells[k].Value.ToString().Trim();
                                }
                            }
                            sw.WriteLine(columnValue);
                        }
                        MessageBox.Show("数据导出成功！ ", "提示信息", MessageBoxButtons.OK, MessageBoxIcon.Information);
                    }
                    catch (Exception er)
                    {
                        MessageBox.Show(er.Message, "提示信息", MessageBoxButtons.OK, MessageBoxIcon.Information);
                    }
                    finally
                    {
                        sw.Close();
                        myStream.Close();
                        GC.Collect();//强行销毁
                    }
                }
            }
            else
            {
                MessageBox.Show("当前系统没有发现可执行的Excel文件，\r\n\r\n如需使用Excel功能请先安装Office程序！", "系统提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);
            }
        }