DataGridView导出到Excel，有一定的判断性
/// <summary>
///方法，导出DataGridView中的数据到Excel文件
/// </summary>
/// <remarks>
/// add com "Microsoft Excel 11.0 Object Library"
/// using Excel=Microsoft.Office.Interop.Excel;
/// using System.Reflection;
/// </remarks>
/// <param name= "dgv"> DataGridView </param>
public static void DataGridViewToExcel(DataGridView dgv)
{

    #region   验证可操作性

    //申明保存对话框
    SaveFileDialog dlg = new SaveFileDialog();
    //默然文件后缀
    dlg.DefaultExt = "xls ";
    //文件后缀列表
    dlg.Filter = "EXCEL文件(*.XLS)|*.xls ";
    //默然路径是系统当前路径
    dlg.InitialDirectory = Directory.GetCurrentDirectory();
    //打开保存对话框
    if (dlg.ShowDialog() == DialogResult.Cancel) return;
    //返回文件路径
    string fileNameString = dlg.FileName;
    //验证strFileName是否为空或值无效
    if (fileNameString.Trim() == " ")
    { return; }
    //定义表格内数据的行数和列数
    int rowscount = dgv.Rows.Count;
    int colscount = dgv.Columns.Count;
    //行数必须大于0
    if (rowscount <= 0)
    {
        MessageBox.Show("没有数据可供保存 ", "提示 ", MessageBoxButtons.OK, MessageBoxIcon.Information);
        return;
    }

    //列数必须大于0
    if (colscount <= 0)
    {
        MessageBox.Show("没有数据可供保存 ", "提示 ", MessageBoxButtons.OK, MessageBoxIcon.Information);
        return;
    }

    //行数不可以大于65536
    if (rowscount > 65536)
    {
        MessageBox.Show("数据记录数太多(最多不能超过65536条)，不能保存 ", "提示 ", MessageBoxButtons.OK, MessageBoxIcon.Information);
        return;
    }

    //列数不可以大于255
    if (colscount > 255)
    {
        MessageBox.Show("数据记录行数太多，不能保存 ", "提示 ", MessageBoxButtons.OK, MessageBoxIcon.Information);
        return;
    }

    //验证以fileNameString命名的文件是否存在，如果存在删除它
    FileInfo file = new FileInfo(fileNameString);
    if (file.Exists)
    {
        try
        {
            file.Delete();
        }
        catch (Exception error)
        {
            MessageBox.Show(error.Message, "删除失败 ", MessageBoxButtons.OK, MessageBoxIcon.Warning);
            return;
        }
    }
    #endregion
    Excel.Application objExcel = null;
    Excel.Workbook objWorkbook = null;
    Excel.Worksheet objsheet = null;
    try
    {
        //申明对象
        objExcel = new Microsoft.Office.Interop.Excel.Application();
        objWorkbook = objExcel.Workbooks.Add(Missing.Value);
        objsheet = (Excel.Worksheet)objWorkbook.ActiveSheet;
        //设置EXCEL不可见
        objExcel.Visible = false;

        //向Excel中写入表格的表头
        int displayColumnsCount = 1;
        for (int i = 0; i <= dgv.ColumnCount - 1; i++)
        {
            if (dgv.Columns[i].Visible == true)
            {
                objExcel.Cells[1, displayColumnsCount] = dgv.Columns[i].HeaderText.Trim();
                displayColumnsCount++;
            }
        }
        //设置进度条
        //tempProgressBar.Refresh();
        //tempProgressBar.Visible   =   true;
        //tempProgressBar.Minimum=1;
        //tempProgressBar.Maximum=dgv.RowCount;
        //tempProgressBar.Step=1;
        //向Excel中逐行逐列写入表格中的数据
        for (int row = 0; row <= dgv.RowCount - 1; row++)
        {
            //tempProgressBar.PerformStep();

            displayColumnsCount = 1;
            for (int col = 0; col < colscount; col++)
            {
                if (dgv.Columns[col].Visible == true)
                {
                    try
                    {
                        objExcel.Cells[row + 2, displayColumnsCount] = dgv.Rows[row].Cells[col].Value.ToString().Trim();
                        displayColumnsCount++;
                    }
                    catch (Exception)
                    {

                    }

                }
            }
        }
        //隐藏进度条
        //tempProgressBar.Visible   =   false;
        //保存文件
        objWorkbook.SaveAs(fileNameString, Missing.Value, Missing.Value, Missing.Value, Missing.Value,
                Missing.Value, Excel.XlSaveAsAccessMode.xlShared, Missing.Value, Missing.Value, Missing.Value,
                Missing.Value, Missing.Value);
    }
    catch (Exception error)
    {
        MessageBox.Show(error.Message, "警告 ", MessageBoxButtons.OK, MessageBoxIcon.Warning);
        return;
    }
    finally
    {
        //关闭Excel应用
        if (objWorkbook != null) objWorkbook.Close(Missing.Value, Missing.Value, Missing.Value);
        if (objExcel.Workbooks != null) objExcel.Workbooks.Close();
        if (objExcel != null) objExcel.Quit();

        objsheet = null;
        objWorkbook = null;
        objExcel = null;
    }
    MessageBox.Show(fileNameString + "\n\n导出完毕! ", "提示 ", MessageBoxButtons.OK, MessageBoxIcon.Information);

}

#endregion