C# datagridview 导出excel

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using System.Windows.Forms;

namespace tree1

{

    public class pp

    {

        public void GenerateExcelAll(System.Data.DataTable dt, DataGridView dgv)

        {

            //导出到execl 

            try

            {

                //没有数据的话就不往下执行 

                if (dt.Rows.Count == 0)

                {

                    MessageBox.Show("当前页面没有数据可以导出！", "导出结果", MessageBoxButtons.OK);

                    return;

                }

                //实例化一个Excel.Application对象 

                Microsoft.Office.Interop.Excel.Application excel = new Microsoft.Office.Interop.Excel.Application();

                //新增加一个工作簿，Workbook是直接保存，不会弹出保存对话框，加上Application会弹出保存对话框，值为false会报错 

                excel.Application.Workbooks.Add(true);

                //让后台执行设置为不可见，为true的话会看到打开一个Excel，然后数据在往里写 

                excel.Visible = false;

                //生成Excel中列头名称

                //生成Excel中列头名称------------------------------**********************************---------------------------------------

                int columnCount = 0;

                for (int i = 0; i < dgv.Columns.Count; i++)

                {

                    if (dgv.Columns[i].Visible)

                    {

                        columnCount = columnCount + 1;

                    }

                }

                string[] headers = new string[columnCount];

                int index = 0;

                for (int i = 0; i < dgv.Columns.Count; i++)

                {

                    if (dgv.Columns[i].Visible)

                    {

                        headers[index] = dgv.Columns[i].HeaderText;

                        index = index + 1;

                    }

                }

                for (int i = 0; i < columnCount; i++)

                {

                    excel.Cells[1, i + 1] = headers[i];

                    //if (dgv.Columns[i].ValueType == typeof(DateTime))

                    //{

                    //    Microsoft.Office.Interop.Excel.Range headRange = excel.Cells[1, i - 1] as Microsoft.Office.Interop.Excel.Range;// as Range;//获取表头单元格

                    //    headRange.ColumnWidth = 22;//设置列宽

                    //}

                }

                //---------------------------------------------------**********************************----------------------------------------

                ////////----------------------------------------**************************************---------------------------------------------

                //把DataGridView当前页的数据保存在Excel中 

                if (dt.Rows.Count > 0)

                {

                    int ccc = dgv.Columns.Count;

                    for (int i = 0; i < dt.Rows.Count; i++)//控制Excel中行，上下的距离，就是可以到Excel最下的行数，比数据长了报错，比数据短了会显示不完 

                    {

                        int columnIndex = 0;

                        for (int j = 0; j < dt.Columns.Count; j++)//控制Excel中列，左右的距离，就是可以到Excel最右的列数，比数据长了报错，比数据短了会显示不完 

                        {

                            if (dgv.Columns[j].Visible)

                            {

                                columnIndex = columnIndex + 1;

                                string str = dt.Rows[i][j].ToString();

                                excel.Cells[i + 2, columnIndex] = "'" + str;//i控制行，从Excel中第2行开始输出第一行数据，j控制列，从Excel中第1列输出第1列数据，"'" +是以string形式保存，所以遇到数字不会转成16进制 

                            }

                        }

                    }

                }

                //设置禁止弹出保存和覆盖的询问提示框 

                excel.DisplayAlerts = false;

                excel.AlertBeforeOverwriting = false;

                //保存工作簿，值为false会报错 

                //excel.Application.Workbooks.Add(false);//.Save();

                //确保Excel进程关闭 

                excel.Save();

                excel.Quit();

                excel = null;

                MessageBox.Show("您所查询的所有数据已经成功导出到您指定的目录！", "导出结果", MessageBoxButtons.OK);

            }

            catch (Exception ex)

            {

                MessageBox.Show(ex.Message, "错误提示");

            }

        }

    }

}