文件打开保存

  /// <summary>
        /// 打开文件
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void btnFile_Click(object sender, EventArgs e)
        {
            using (OpenFileDialog openFile = new OpenFileDialog())
            {
                openFile.Filter = "文本文档|*.txt|All files (*.*)|*.*";
                if (openFile.ShowDialog() != DialogResult.OK)
                {
                    return;
                }
                using (FileStream fileStream = new FileStream(openFile.FileName, FileMode.Open, FileAccess.Read))
                {
                    using (StreamReader sr = new StreamReader(fileStream))
                    {
                        while (!sr.EndOfStream)
                        {
                            string line = sr.ReadLine();
                            this.txtContent.Text = line;
                        }
                    }
                }
            }
        }
        /// <summary>
        /// 保存文件
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void btnSaveFile_Click(object sender, EventArgs e)
        {
            
            using (SaveFileDialog saveFile = new SaveFileDialog())
            {
               saveFile.Filter = "文本文档|*.txt|All files (*.*)|*.*";
                if (saveFile.ShowDialog() != System.Windows.Forms.DialogResult.OK)
                {
                    return;
                }
                using (FileStream fs = new FileStream(saveFile.FileName, FileMode.OpenOrCreate, FileAccess.ReadWrite))
                {
                    //using (StreamWriter sw = new StreamWriter(fs))
                    //{
                    //    sw.Write(txtContent.Text);
                    //    sw.Flush();
                    //}
                  string str=  txtContent.Text;
                  byte[] result =  Encoding.Default.GetBytes(str);
                    fs.Write(result, 0, result.Length);
                    fs.Flush();
                }
            }
        }