SaveFileDialog dg = new SaveFileDialog();//保存文件对话框，选择导出文件的存放位置
dg.Filter = "xls files(*.xls)|*.xls";//保存为xls格式
if (dg.ShowDialog() == DialogResult.OK)
{
    string filepath = dg.FileName.ToString();//保存文件的路径
   
    Excel.Workbooks objBooks;//接口 workbooks
    Excel.Sheets objSheets;// 接口 sheets
    Excel._Worksheet objSheet;//接口 worksheet
    excel = new Excel.Application();
    objBooks = excel.Workbooks;
    Object miss = System.Reflection.Missing.Value;
    objBook = objBooks.Add(miss);
    objSheets = objBook.Sheets;
    objSheet = (Excel._Worksheet)objSheets[1];
    try
    {

if (dataGridView1.Rows.Count == 0) //没有数据的话就不往下执行  
return;
excel.Visible = false; //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  
for (int i = 0; i < dataGridView1.Columns.Count; i++) //生成Excel中列头名称  
{
  objSheet.Cells[1, i + 1] = dataGridView1.Columns[i].HeaderText;
}

for (int i = 0; i < dataGridView1.Rows.Count ; i++) //把DataGridView当前页的数据保存在Excel中  
{
       for (int j = 0; j < dataGridView1.Columns.Count; j++)
    {
    if (dataGridView1[j, i].ValueType == typeof(string))
    {
objSheet.Cells[i + 2, j + 1] = "'" + dataGridView1[j, i].Value.ToString();
    }
    else
    {
objSheet.Cells[i + 2, j + 1] = dataGridView1[j, i].Value.ToString();
    }
}
}
objBook.SaveCopyAs(filepath);
//设置禁止弹出保存和覆盖的询问提示框  
excel.DisplayAlerts = false;
excel.AlertBeforeOverwriting = false;

//确保Excel进程关闭  
objBooks.Close();
excel.Workbooks.Close();
excel.Quit();
excel = null;
GC.Collect();
MessageBox.Show("数据导出完成!", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
if (System.IO.File.Exists(filepath))
System.Diagnostics.Process.Start(filepath); //保存成功后打开此文件
}
catch (Exception ex)
{
MessageBox.Show(ex.Message, "错误提示");
 }
}