C#中DataGridView导出Excel的两种方法

#region
      SaveFileDialog saveFileDialog = new SaveFileDialog();
      saveFileDialog.Filter = "Execl files (*.xls)|*.xls";
      saveFileDialog.FilterIndex = 0;
      saveFileDialog.RestoreDirectory = true;
      saveFileDialog.CreatePrompt = true;
      saveFileDialog.Title = "Export Excel File";
      saveFileDialog.ShowDialog();
      if (saveFileDialog.FileName == "")
        return;
      Stream myStream;
      myStream = saveFileDialog.OpenFile();
      StreamWriter sw = new StreamWriter(myStream, System.Text.Encoding.GetEncoding(-0));
 
      string str = "";
      try
      {
        for (int i = 0; i < dataGridView1.ColumnCount; i++)
        {
          if (i > 0)
          {
            str += "t";
          }
          str += dataGridView1.Columns[i].HeaderText;
        }
        sw.WriteLine(str);
        for (int j = 0; j < dataGridView1.Rows.Count; j++)
        {
          string tempStr = "";
          for (int k = 0; k < dataGridView1.Columns.Count; k++)
          {
            if (k > 0)
            {
              tempStr += "t";
            }
            tempStr += dataGridView1.Rows[j].Cells[k].Value.ToString();
          }
          sw.WriteLine(tempStr);
        }
        sw.Close();
        myStream.Close();
      }
 
      catch (Exception ex)
      {
        //MessageBox.Show(ex.ToString());
      }
      finally
      {
        sw.Close();
        myStream.Close();
      }
#endregion

using System;
using System.Collections.Generic;
using System.Windows.Forms;
using System.Text;
using System.Diagnostics;
using System.IO;
using Microsoft.Office.Interop.Excel;
 
namespace Excel
{
  public class Export
  {
    /// <summary>
    /// DataGridView导出Excel
    /// </summary>
    /// <param name="strCaption">Excel文件中的标题</param>
    /// <param name="myDGV">DataGridView 控件</param>
    /// <returns>0:成功;1:DataGridView中无记录;2:Excel无法启动;9999:异常错误</returns>
    public int ExportExcel(string strCaption, DataGridView myDGV, SaveFileDialog saveFileDialog)
    {
      int result = 9999;
      
      //保存
      
      saveFileDialog.Filter = "Execl files (*.xls)|*.xls";
      saveFileDialog.FilterIndex = 0;
      saveFileDialog.RestoreDirectory = true;
      //saveFileDialog.CreatePrompt = true;
      saveFileDialog.Title = "Export Excel File";
      if ( saveFileDialog.ShowDialog()== DialogResult.OK)
      {
        if (saveFileDialog.FileName == "")
        {
          MessageBox.Show("请输入保存文件名！");
          saveFileDialog.ShowDialog();
        }
          // 列索引，行索引，总列数，总行数
        int ColIndex = 0;
        int RowIndex = 0;
        int ColCount = myDGV.ColumnCount;
        int RowCount = myDGV.RowCount;
 
        if (myDGV.RowCount == 0)
        {
          result = 1;
        }
 
        // 创建Excel对象
        Microsoft.Office.Interop.Excel.Application xlApp = new Microsoft.Office.Interop.Excel.ApplicationClass();
        if (xlApp == null)
        {
          result = 2;
        }
        try
        {
          // 创建Excel工作薄
          Microsoft.Office.Interop.Excel.Workbook xlBook = xlApp.Workbooks.Add(true);
          Microsoft.Office.Interop.Excel.Worksheet xlSheet = (Microsoft.Office.Interop.Excel.Worksheet)xlBook.Worksheets[1];
          // 设置标题
          Microsoft.Office.Interop.Excel.Range range = xlSheet.get_Range(xlApp.Cells[1, 1], xlApp.Cells[1, ColCount]); //标题所占的单元格数与DataGridView中的列数相同
          range.MergeCells = true;
          xlApp.ActiveCell.FormulaR1C1 = strCaption;
          xlApp.ActiveCell.Font.Size = 20;
          xlApp.ActiveCell.Font.Bold = true;
          xlApp.ActiveCell.HorizontalAlignment = Microsoft.Office.Interop.Excel.Constants.xlCenter;
          // 创建缓存数据
          object[,] objData = new object[RowCount + 1, ColCount];
          //获取列标题
          foreach (DataGridViewColumn col in myDGV.Columns)
          {
            objData[RowIndex, ColIndex++] = col.HeaderText;
          }
          // 获取数据
          for (RowIndex = 1; RowIndex < RowCount; RowIndex++)
          {
            for (ColIndex = 0; ColIndex < ColCount; ColIndex++)
            {
              if (myDGV[ColIndex, RowIndex - 1].ValueType == typeof(string)
                || myDGV[ColIndex, RowIndex - 1].ValueType == typeof(DateTime))//这里就是验证DataGridView单元格中的类型,如果是string或是DataTime类型,则在放入缓存时在该内容前加入" ";
              {
                objData[RowIndex, ColIndex] = "" + myDGV[ColIndex, RowIndex - 1].Value;
              }
              else
              {
                objData[RowIndex, ColIndex] = myDGV[ColIndex, RowIndex - 1].Value;
              }
            }
            System.Windows.Forms.Application.DoEvents();
          }
          // 写入Excel
          range = xlSheet.get_Range(xlApp.Cells[2, 1], xlApp.Cells[RowCount, ColCount]);
          range.Value2 = objData;
 
          xlBook.Saved = true;
          xlBook.SaveCopyAs(saveFileDialog.FileName);
        }
        catch (Exception err)
        {
          result = 9999;
        }
        finally
        {
          xlApp.Quit();
          GC.Collect(); //强制回收
        }
        //返回值
        result = 0;
      }
      
      return result;
    }
 
 
  }
}

range = xlSheet.get_Range(xlApp.Cells[2, 1], xlApp.Cells[RowCount + 2, ColCount]);
range.NumberFormatLocal = "@";
range.Value2 = objData;