C#写入文件

 private void 保存ToolStripMenuItem_Click(object sender, EventArgs e)
        {
            SaveFileDialog FiL0 = new SaveFileDialog(); // 创建对象
            FiL0.Title = "";  //标题为空
            FiL0.InitialDirectory = @"C:\";  //默认目录为 C:\ 
            FiL0.Filter = "txt files(*.txt)|*.txt|xls files(*.xls)|*.xls|All files(*.*)|*.*"; //设置文件格式
            FiL0.RestoreDirectory = true;   //保存对话框是否记忆上次打开的目录
            FiL0.ShowDialog();   //显示对话窗

            string path0 = FiL0.FileName; // 获取文件名
            textBox2.Text = path0;
            if (path0 =="")   //如果没有文件名，
            {
                return;    //返回对话窗
            }
            using (FileStream fsWrite = new FileStream(path0, FileMode.OpenOrCreate, FileAccess.Write)) {
                byte[] buffer = Encoding.Default.GetBytes(textBox1.Text);
                fsWrite.Write(buffer, 0, buffer.Length);
                MessageBox.Show("保存成功");
            }
        }