C#保存Txt文件

private void SavetxtData_Click(object sender, EventArgs e)
{
SaveFileDialog saveFileDialog = new SaveFileDialog();
saveFileDialog.Filter = "(*.txt)|*.txt|(*.*)|*.*";
saveFileDialog.FileName = "文件" + DateTime.Now.ToString("yyyyMMddHHmm") + ".txt";
//將日期時間作為文件名
if (saveFileDialog.ShowDialog() == DialogResult.OK)
{
StreamWriter streamWriter = new StreamWriter(saveFileDialog.FileName, true);
streamWriter.Write(this.rxtextBox.Text);
streamWriter.Close();
}
}