《C#程序设计》第二次作业 简易记事本

using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.IO;using System.Linq;using System.Text;using System.Threading.Tasks;using System.Windows.Forms;namespace WindowsFormsApplication9{    public partial class frmEditor : Form    {        public frmEditor()        {            InitializeComponent();        }        /// <summary>        /// 保存原始内容        /// </summary>        private String OriginalContent = "";        /// <summary>        /// 打开的文件名        /// </summary>        private String _FileName = "";        public String FileName        {            get            {                return _FileName;            }            set            {                _FileName = value;                //在赋值时同步更新窗体标题                Text = Path.GetFileName(value) + "-我的记事本";            }        }   private void Form1_Load(object sender, EventArgs e)        {            lblTimer.Text = "";            lblInfo.Text = "";            Text = "-我的记事本";        }        private void timer1_Tick(object sender, EventArgs e)        {            lblTimer.Text = DateTime.Now.ToString();        }        private void btnOpen_Click(object sender, EventArgs e)        {            Open();        }        private void Open()        {            if (openFileDialog1.ShowDialog() == DialogResult.OK)            {                FileName = openFileDialog1.FileName;                try                {                    OriginalContent = File.ReadAllText(FileName);                    txtEditor.Text = OriginalContent;                }                catch (Exception)                {                    lblInfo.Text = "无法打开文件";                }            }        }        /// <summary>        /// 保存到文件        /// </summary>        private void Save()        {            //当内容己更改时，此标记为True，            bool ShouldSave = false;            //如果文件名不为空，表明当前是文本框中的内容是来自于文件            if (FileName != "")            {                //如果内容己更改                if (txtEditor.Text != OriginalContent                    && MessageBox.Show("文件己修改，保存吗？",                    "保存文件",                    MessageBoxButtons.YesNo) == DialogResult.Yes)                {                    ShouldSave = true;                }            }            else            {                //如果用户输入了内容，并且指定了一个文件名                if (txtEditor.Text != "" && saveFileDialog1.ShowDialog() == DialogResult.OK)                {                    FileName = saveFileDialog1.FileName;                    ShouldSave = true;                }            }            if (ShouldSave)            {                try                {                    File.WriteAllText(FileName, txtEditor.Text);                    OriginalContent = txtEditor.Text;                    lblInfo.Text = "文件己保存";                }                catch (Exception)                {                    lblInfo.Text = "文件保存失败";                }            }        }        private void btnsave_Click(object sender, EventArgs e)        {            Save();        }        private void frmEditor_FormClosing(object sender, FormClosingEventArgs e)        {            Save();        }        }    }