winfrom gridview 导出到Excel文件的代码

SaveFileDialog saveFileDialog = new SaveFileDialog();
saveFileDialog.Filter = "Execl files (*.xls)|*.xls";
saveFileDialog.FilterIndex = 0;
saveFileDialog.RestoreDirectory = true;
saveFileDialog.CreatePrompt = true;
saveFileDialog.Title = "导出Excel文件到";

DateTime now = DateTime.Now;
saveFileDialog.FileName = now.Year.ToString().PadLeft(2)
+ now.Month.ToString().PadLeft(2, '0')
+ now.Day.ToString().PadLeft(2, '0') + "-"
+ now.Hour.ToString().PadLeft(2, '0')
+ now.Minute.ToString().PadLeft(2, '0')
+ now.Second.ToString().PadLeft(2, '0');

saveFileDialog.ShowDialog();

Stream myStream;
myStream = saveFileDialog.OpenFile();
StreamWriter sw = new StreamWriter(myStream, System.Text.Encoding.GetEncoding("gb2312"));
string str = "";
try
{
//写标题
for (int i = 0; i < dataGridView1.ColumnCount; i++)
{
if (i > 0)
{
str += "\t";
}
str += dataGridView1.Columns[i].HeaderText;
}

sw.WriteLine(str);
//写内容
for (int j = 0; j < dataGridView1.Rows.Count-1; 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();
}