前言
https://blog.csdn.net/IT_xiao_guang_guang/article/details/104217491
本地数据库表中有46785条数据，测试正常
初次运行程序第一次导出，用时在4-5s左右；此后再导出用时在2-3s左右；可能与缓存有关
支持导出为.xls和.xlsx格式
可以自定义字体和字号
exe测试文件下载地址：https://www.lanzous.com/i95st5g
密码：test
实现步骤
一、安装NPOI
右键项目 → "管理NuGet程序包" → 搜索NPOI → 安装
二、创建类
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using NPOI.SS.UserModel;
using NPOI.HSSF.UserModel;//导出xls格式用HSSF
using NPOI.XSSF.UserModel;//导出xlsx格式用XSSF
using System.IO;
using System.Runtime.InteropServices;
using System.Diagnostics;
using NPOI.SS.Util;
namespace ExportToExcel
{
public class ExportDgvToExcel
{
#region NPOI DataGridView 导出 EXCEL
///
/// NPOI DataGridView 导出 EXCEL
/// 03版Excel-xls最大行数是65536行,最大列数是256列
/// 07版Excel-xlsx最大行数是1048576行,最大列数是16384列
///
/// 默认保存文件名
/// DataGridView
/// 字体名称
/// 字体大小
public void ExportExcel(string fileName, DataGridView dgv, string fontname, short fontsize)
{
IWorkbook workbook;
ISheet sheet;
Stopwatch sw = null;
//判断datagridview中内容是否为空
if (dgv.Rows.Count == 0)
{
MessageBox.Show("DataGridView中内容为空,请先导入数据!", "提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);
return;
}
//保存文件
string saveFileName = "";
SaveFileDialog saveFileDialog = new SaveFileDialog();
saveFileDialog.DefaultExt = "xls";
saveFileDialog.Filter = "Excel文件(*.xls)|*.xls|Excel文件(*.xlsx)|*.xlsx";
saveFileDialog.RestoreDirectory = true;
saveFileDialog.Title = "Excel文件保存路径";
saveFileDialog.FileName = fileName;
MemoryStream ms = new MemoryStream(); //MemoryStream
if (saveFileDialog.ShowDialog() == DialogResult.OK)
{
//**程序开始计时**//
sw = new Stopwatch();
sw.Start();
saveFileName = saveFileDialog.FileName;
//检测文件是否被占用
if (!CheckFiles(saveFileName))
{
MessageBox.Show("文件被占用,请关闭文件" + saveFileName);
workbook = null;
ms.Close();
ms.Dispose();
return;
}
}
else
{
workbook = null;
ms.Close();
ms.Dispose();
}
//*** 根据扩展名xls和xlsx来创建对象
string fileExt = Path.GetExtension(saveFileName).ToLower();
if (fileExt == ".xlsx")
{
workbook = new XSSFWorkbook();
}
else if (fileExt == ".xls")
{
workbook = new HSSFWorkbook();
}
else
{
workbook = null;
}
//***
//创建Sheet
if (workbook != null)
{
sheet = workbook.CreateSheet("Sheet1");//Sheet的名称
}
else
{
return;
}
//设置单元格样式
ICellStyle cellStyle = workbook.CreateCellStyle();
//水平居中对齐和垂直居中对齐
cellStyle.Alignment = NPOI.SS.UserModel.HorizontalAlignment.Center;
cellStyle.VerticalAlignment = NPOI.SS.UserModel.VerticalAlignment.Center;
//设置字体
IFont font = workbook.CreateFont();
font.FontName = fontname;//字体名称
font.FontHeightInPoints = fontsize;//字号
font.Color = NPOI.HSSF.Util.HSSFColor.Black.Index;//字体颜色
cellStyle.SetFont(font);
//添加列名
IRow headRow = sheet.CreateRow(0);
for (int i = 0; i < dgv.Columns.Count; i++)
{
//隐藏行列不导出
if (dgv.Columns[i].Visible == true)
{
headRow.CreateCell(i).SetCellValue(dgv.Columns[i].HeaderText);
headRow.GetCell(i).CellStyle = cellStyle;
}
}
//根据类型写入内容
for (int rowNum = 0; rowNum < dgv.Rows.Count; rowNum++)
{
///跳过第一行,第一行为列名
IRow dataRow = sheet.CreateRow(rowNum + 1);
for (int columnNum = 0; columnNum < dgv.Columns.Count; columnNum++)
{
int columnWidth = sheet.GetColumnWidth(columnNum) / 256; //列宽
//隐藏行列不导出
if (dgv.Rows[rowNum].Visible == true && dgv.Columns[columnNum].Visible == true)
{
//防止行列超出Excel限制
if (fileExt == ".xls")
{
//03版Excel最大行数是65536行,最大列数是256列
if (rowNum > 65536)
{
MessageBox.Show("行数超过Excel限制!");
return;
}
if (columnNum > 256)
{
MessageBox.Show("列数超过Excel限制!");
return;
}
}
else if (fileExt == ".xlsx")
{
//07版Excel最大行数是1048576行,最大列数是16384列
if (rowNum > 1048576)
{
MessageBox.Show("行数超过Excel限制!");
return;
}
if (columnNum > 16384)
{
MessageBox.Show("列数超过Excel限制!");
return;
}
}
ICell cell = dataRow.CreateCell(columnNum);
if (dgv.Rows[rowNum].Cells[columnNum].Value == null)
{
cell.SetCellType(CellType.Blank);
}
else
{
if (dgv.Rows[rowNum].Cells[columnNum].ValueType.FullName.Contains("System.Int32"))
{
cell.SetCellValue(Convert.ToInt32(dgv.Rows[rowNum].Cells[columnNum].Value));
}
else if (dgv.Rows[rowNum].Cells[columnNum].ValueType.FullName.Contains("System.String"))
{
cell.SetCellValue(dgv.Rows[rowNum].Cells[columnNum].Value.ToString());
}
else if (dgv.Rows[rowNum].Cells[columnNum].ValueType.FullName.Contains("System.Single"))
{
cell.SetCellValue(Convert.ToSingle(dgv.Rows[rowNum].Cells[columnNum].Value));
}
else if (dgv.Rows[rowNum].Cells[columnNum].ValueType.FullName.Contains("System.Double"))
{
cell.SetCellValue(Convert.ToDouble(dgv.Rows[rowNum].Cells[columnNum].Value));
}
else if (dgv.Rows[rowNum].Cells[columnNum].ValueType.FullName.Contains("System.Decimal"))
{
cell.SetCellValue(Convert.ToDouble(dgv.Rows[rowNum].Cells[columnNum].Value));
}
else if (dgv.Rows[rowNum].Cells[columnNum].ValueType.FullName.Contains("System.DateTime"))
{
cell.SetCellValue(Convert.ToDateTime(dgv.Rows[rowNum].Cells[columnNum].Value).ToString("yyyy-MM-dd"));
}
else if (dgv.Rows[rowNum].Cells[columnNum].ValueType.FullName.Contains("System.DBNull"))
{
cell.SetCellValue("");
}
}
//设置列宽
IRow currentRow;
if (sheet.GetRow(rowNum) == null)
{
currentRow = sheet.CreateRow(rowNum);
}
else
{
currentRow = sheet.GetRow(rowNum);
}
if (currentRow.GetCell(columnNum) != null)
{
ICell currentCell = currentRow.GetCell(columnNum);
int length = Encoding.Default.GetBytes(currentCell.ToString()).Length;
if (columnWidth < length)
{
columnWidth = length + 10; //设置列宽数值
}
}
sheet.SetColumnWidth(columnNum, columnWidth * 256);
//单元格样式
dataRow.GetCell(columnNum).CellStyle = cellStyle;
}
}
}
//保存为Excel文件
workbook.Write(ms);
FileStream file = new FileStream(saveFileName, FileMode.Create);
workbook.Write(file);
file.Close();
workbook = null;
ms.Close();
ms.Dispose();
//**程序结束计时**//
sw.Stop();
double totalTime = sw.ElapsedMilliseconds / 1000.0;
MessageBox.Show(fileName + " 导出成功\n耗时" + totalTime + "s", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
}
#endregion
#region 检测文件是否被占用
///
/// 判定文件是否打开
///
[DllImport("kernel32.dll")]
public static extern IntPtr _lopen(string lpPathName, int iReadWrite);
[DllImport("kernel32.dll")]
public static extern bool CloseHandle(IntPtr hObject);
public const int OF_READWRITE = 2;
public const int OF_SHARE_DENY_NONE = 0x40;
public readonly IntPtr HFILE_ERROR = new IntPtr(-1);
///
/// 检测文件被占用
///
/// 要检测的文件路径
/// 三、调用
private void btnExport_Click_1(object sender, EventArgs e)
{
ExportDgvToExcel export = new ExportDgvToExcel();
export.ExportExcel("", dgv, "宋体", 11);//默认文件名,DataGridView控件的名称,字体,字号
}