C#编写一个较完整的记事本程序

开发环境

Visual Studio 2019

• 至少需安装 .NET桌面开发

创建项目并配置

创建窗体文件

配置项目名称及框架

设计界面

创建窗体文件，将控件摆放位置如下，参考系统自带的记事本程序

窗体添加的控件和组件如下

• 控件及组件在工具箱查找

窗体属性

快捷键设置

• 杂项 --> ShortcutKeys

程序属性

项目属性如下图，在创建项目时就已定好了框架，如果在另一台主机上的框架版本比目前项目框架版本低的话，则运行不起来

• 文章末尾有整个程序的压缩包链接可下载，如需直接运行则需下载对应的.NET Framework 4.7.2框架

程序图标可在此设置，生成程序后的图标如下图，此文件夹下的程序文件可在第二台主机上直接运行（项目\bin\Debug目录下就是生成程序文件的存放位置，双击程序文件即可运行）

代码演示

代码开头的using部分

• 注释部分需自行添加

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.IO;//提供了关于文件、数据流的读取和写入操作
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Diagnostics;//提供了用于与事件日志、性能计数器和系统进程进行交互的类

主要功能

1.新建文件：

    private void 新建NToolStripMenuItem_Click(object sender, EventArgs e)
    {
        if (txtBox.Modified == true)
        {
            DialogResult dr = MessageBox.Show("文件发生变化，是否更改保存？", "注意", MessageBoxButtons.YesNoCancel);
            if (dr == DialogResult.Yes)
            {
                保存SToolStripMenuItem_Click(sender, e);
                return;
            }
            else if (dr == DialogResult.Cancel)
            {
                return;
            }
            txtBox.Clear();
            this.Text = "NewNotepad";
        }
        else
        {
            txtBox.Clear();
            this.Text = "NewNotepad";
        }
    }

新建文件

2.打开：

    private void 打开ToolStripMenuItem_Click(object sender, EventArgs e)
    {
        if (openFileDialog.ShowDialog() == DialogResult.OK)
        {
            filename = openFileDialog.FileName;
            OpenFile();
        }
    }
    protected void OpenFile()
    {
        try
        {
            txtBox.Clear();
            txtBox.Text = File.ReadAllText(filename);
        }
        catch
        { MessageBox.Show("Error!"); }
    }

打开

3.保存：

    private void 保存SToolStripMenuItem_Click(object sender, EventArgs e)
    {
        try
        {
            StreamWriter sw = File.AppendText(Application.ExecutablePath);
            sw.Write(txtBox.Text);
            sw.Dispose();
        }
        catch
        {
            SaveFileDialog sf = new SaveFileDialog();
            sf.DefaultExt = "*.txt";
            sf.Filter = "文本文档(.txt)|*.txt";
            if (sf.ShowDialog() == DialogResult.OK)
            {
                StreamWriter sw = File.AppendText(sf.FileName);
                sw.Write(txtBox.Text);
                sw.Dispose();
            }
        }
    }

保存

4.另存为：

    private void 另存为ToolStripMenuItem_Click(object sender, EventArgs e)
    {
        string name;
        //SaveFileDialog类
        SaveFileDialog save = new SaveFileDialog();
        //过滤器
        save.Filter = "*.txt|*.TXT|(*.*)|*.*";
        //显示
        if (save.ShowDialog() == DialogResult.OK)
        {
            name = save.FileName;
            FileInfo info = new FileInfo(name);
            //info.Delete();
            StreamWriter writer = info.CreateText();
            writer.Write(txtBox.Text);
            writer.Close();
        }
    }

另存为

5.打印：

    private void 打印PToolStripMenuItem_Click(object sender, EventArgs e)
    {
        //显示允许用户选择打印机的选项及其它打印选项的对话框
        this.printDialog.Document = this.printDocument;
        this.printDialog.PrinterSettings = this.pageSetupDialog.PrinterSettings;
        //向打印机发送打印指令
        if (this.printDialog.ShowDialog() == DialogResult.OK)
        {
            try
            {
                this.printDocument.Print();
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message, "错误信息！", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
        }
    }

打印

6.编辑：

• 根据输入是否输入内容控制是否启用功能

    private void 编辑ToolStripMenuItem_Click(object sender, EventArgs e)
    {
        剪切ToolStripMenuItem.Enabled = txtBox.Modified;
        if (txtBox.SelectedText == "")
        {
            剪切ToolStripMenuItem.Enabled = false;
            复制ToolStripMenuItem.Enabled = false;
            删除ToolStripMenuItem.Enabled = false;
        }
        else
        {
            剪切ToolStripMenuItem.Enabled = true;
            复制ToolStripMenuItem.Enabled = true;
            删除ToolStripMenuItem.Enabled = true;
        }
        if (txtBox.Text == "")
        {
            查找ToolStripMenuItem.Enabled = false;
            查找下一个ToolStripMenuItem.Enabled = false;
            查找上一个ToolStripMenuItem.Enabled = false;
            替换ToolStripMenuItem.Enabled = false;
        }
        else
        {
            查找ToolStripMenuItem.Enabled = true;
            查找下一个ToolStripMenuItem.Enabled = true;
            查找上一个ToolStripMenuItem.Enabled = true;
            替换ToolStripMenuItem.Enabled = true;
        }
        if (Clipboard.GetText() == "")
            粘贴ToolStripMenuItem.Enabled = false;
        else
            粘贴ToolStripMenuItem.Enabled = true;
    }

编辑

7.查找：

• 查找功能不够完善，混用查找上一项和查找下一项效果不理想

    TextBox txtInput = new TextBox()
    {
        Font = new Font("宋体", 10)
    };
    TextBox txtInputReplace = new TextBox()
    {
        Font = new Font("宋体", 10)
    };
    Label lblSearch = new Label
    {
        Text = "查找内容：",
        Size = new Size(65, 25),
        Location = new Point(5, 22)
    };
    Label lblDirection = new Label
    {
        Text = "查找方向：",
        Size = new Size(65, 25),
        Location = new Point(5, 58)
    };
    Button FindNext = new Button
    {
        Name = "btnFindNext",
        Text = "查找下一项",
        Size = new Size(80, 25),
        Location = new Point(265, 15)
    };
    Button Cancel = new Button
    {
        Name = "btnCancel",
        Text = "取消",
        Size = new Size(80, 25),
        Location = new Point(265, 50)
    };
    RadioButton down = new RadioButton
    {
        Name = "radDown",
        Text = "向下",
        Size = new Size(55, 25),
        Location = new Point(70, 53),
        Checked = true
    };
    RadioButton upward = new RadioButton
    {
        Name = "radUpward",
        Text = "向上",
        Size = new Size(55, 25),
        Location = new Point(140, 53),
        Checked = false
    };
    new Form FindForm = new Form
    {
        Text = "查找文本",
        FormBorderStyle = FormBorderStyle.FixedSingle,
        MaximizeBox = false,
        MinimizeBox = false
    };
    private void 查找ToolStripMenuItem_Click(object sender, EventArgs e)
    {
        //显示查找对话框
        txtInput.Size = new Size(190, 33);
        txtInput.Location = new Point(70, 15);
        txtInput.Multiline = true;

        FindNext.Click += new EventHandler(Direction_Click);
        //FindNext.Click += new EventHandler(Visible_Click);

        Cancel.Click += new EventHandler(Cancel_Click);

        FindForm.Controls.Add(lblSearch);
        FindForm.Controls.Add(lblDirection);
        FindForm.Controls.Add(txtInput);
        FindForm.Controls.Add(down);
        FindForm.Controls.Add(upward);
        FindForm.Controls.Add(FindNext);
        FindForm.Controls.Add(Cancel);
        FindForm.Top = this.Top + 50;
        FindForm.Left = this.Left + 50;
        FindForm.Height = 120;
        FindForm.Width = 380;
        FindForm.StartPosition = FormStartPosition.CenterParent;
        FindForm.ShowDialog();
    }
    private void Cancel_Click(object sender, EventArgs e)
    {
        //关闭对话框
        FindForm.Close();
        ReplaceForm.Close();
    }
    private void Direction_Click(object sender, EventArgs e)
    {
        //选择字符查找方向
        if (down.Checked == true)
        {
            Find_Click(sender, e);
        }
        else if (upward.Checked == true)
        {
            FindLast_Click(sender, e);
        }
    }
            int nextPosition, firstPosition;
    string word;
    Boolean IF = false;
    private void Find_Click(object sender, EventArgs e)
    {
        txtBox.Focus();
        FindWords(txtInput.Text);
    }
    private void FindWords(string words)
    {
        //向下查找字符
        if (nextPosition >= txtBox.Text.Length)
            nextPosition = 0;
        firstPosition = txtBox.Text.IndexOf(words, nextPosition);
        if (firstPosition == -1)
            nextPosition = 0;
        else
        {
            txtBox.Select(firstPosition, words.Length);
            nextPosition = firstPosition + 1;
        }
        word = words;
        IF = true;
    }

查找

8. 查找下一项 ：

    private void 查找下一个ToolStripMenuItem_Click(object sender, EventArgs e)
    {
        //查找下一项，如果未查找过，则显示查找对话框
        down.Checked = true;
        upward.Checked = false;
        try
        {
            FindWords(word);
        }
        catch
        {
            查找ToolStripMenuItem_Click(sender, e);
        }
    }

查找下一项

9.查找上一项：

    private void FindWordsLast(string words)
    {
        //向上查找字符
        if (IF == false)
            nextPosition = txtBox.Text.Length;
        if (nextPosition < 0)
            nextPosition = txtBox.Text.Length;

        firstPosition = txtBox.Text.LastIndexOf(words, nextPosition);

        if (firstPosition == -1)
            nextPosition = txtBox.Text.Length;
        else
        {
            txtBox.Select(firstPosition, words.Length);
            nextPosition = firstPosition - 1;
        }
        word = words;
        IF = true;
    }
    private void 查找上一个ToolStripMenuItem_Click(object sender, EventArgs e)
    {
        //查找上一项，如果未查找过，则显示查找对话框
        upward.Checked = true;
        down.Checked = false;
        try
        {
            FindWordsLast(word);
        }
        catch
        {
            查找ToolStripMenuItem_Click(sender, e);
        }
    }

查找上一项

10.替换：

    Label LblReplace = new Label
    {
        Name = "lblReplace",
        Text = "替换：",
        Size = new Size(55, 25),
        Location = new Point(15, 50)
    };
    Form ReplaceForm = new Form
    {
        Text = "替换文本",
        FormBorderStyle = FormBorderStyle.FixedSingle,
        MaximizeBox = false,
        MinimizeBox = false
    };
    private void 替换ToolStripMenuItem_Click(object sender, EventArgs e)
    {
        txtInput.Size = new Size(190, 30);
        txtInput.Location = new Point(70, 12);
        txtInput.Multiline = true;

        txtInputReplace.Size = new Size(190, 30);
        txtInputReplace.Location = new Point(70, 47);
        txtInputReplace.Multiline = true;

        Button Replace = new Button
        {
            Name = "btnReplace",
            Text = "替换",
            Size = new Size(80, 25),
            Location = new Point(265, 15)
        };
        Replace.Click += new EventHandler(Replace_Click);
        Cancel.Click += new EventHandler(Cancel_Click);

        ReplaceForm.Controls.Add(lblSearch);
        ReplaceForm.Controls.Add(LblReplace);
        ReplaceForm.Controls.Add(txtInput);
        ReplaceForm.Controls.Add(txtInputReplace);
        ReplaceForm.Controls.Add(Replace);
        ReplaceForm.Controls.Add(Cancel);
        ReplaceForm.Top = this.Top + 50;
        ReplaceForm.Left = this.Left + 50;
        ReplaceForm.Height = 140;
        ReplaceForm.Width = 380;
        ReplaceForm.StartPosition = FormStartPosition.CenterParent;
        ReplaceForm.ShowDialog();
    }
    private void Replace_Click(object sender, EventArgs e)
    {
        txtBox.Text = txtBox.Text.Replace(txtInput.Text, txtInputReplace.Text);
    }

替换

11. 字体选择：

• 直接调用控件即可

    private void 字体ToolStripMenuItem_Click(object sender, EventArgs e)
    {
        //提示用户从本地计算机安装的字体中选择字体字号
        FontDialog fontDialog = new FontDialog();
        if (fontDialog.ShowDialog() == DialogResult.OK)
        {
            txtBox.Font = fontDialog.Font;
        }
    }

字体选择

12. 关于记事本：

• 新建一个窗口，根据自己的喜好添加标签及摆放位置

    private void 关于记事本ToolStripMenuItem_Click(object sender, EventArgs e)
    {
        //关于记事本说明
        Label lblTitle = new Label()
        {
            Text = "多功能记事本",
            Size = new Size(150, 25),
            Location = new Point(100, 50)
        };
        Label lblEdition = new Label()
        {
            Text = "版本号：个性测试版",
            Size = new Size(150, 25),
            Location = new Point(85, 100)
        };
        Label lblMail = new Label()
        {
            Text = "E-Mail：",
            Size = new Size(55, 25),
            Location = new Point(30, 180)
        };
        LinkLabel llblMail = new LinkLabel()
        {
            Text = "2417525822@qq.com",
            Size = new Size(110, 25),
            Location = new Point(85, 180)
        };
        Label lblCNDS = new Label()
        {
            Text = "CNDS博客：",
            Size = new Size(65, 25),
            Location = new Point(20, 220)
        };
        LinkLabel llblCNDS = new LinkLabel()
        {
            Text = "https://blog.csdn.net/UFO_Harold",
            Size = new Size(200, 25),
            Location = new Point(85, 220)
        };
        Form about = new Form
        {
            Text = "关于记事本",
            FormBorderStyle = FormBorderStyle.FixedSingle,
            MaximizeBox = false
        };

        llblCNDS.Click += new EventHandler(LlblCNDS_Click);
        about.Controls.Add(lblTitle);
        about.Controls.Add(lblEdition);
        about.Controls.Add(lblMail);
        about.Controls.Add(llblMail);
        about.Controls.Add(lblCNDS);
        about.Controls.Add(llblCNDS);
        about.Top = this.Top + this.Height / 2 - about.Height / 2;
        about.Left = this.Left + this.Width / 2 - about.Width / 2;
        about.StartPosition = FormStartPosition.CenterParent;
        about.ShowDialog();
    }

关于记事本

• 效果如图

完整代码

namespace Notepad
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        string filename = "";
        public Form1(string filename)
        {
            InitializeComponent();
            if (filename != null)
            {
                this.filename = filename;
                OpenFile();
            }
        }
        private void 新建NToolStripMenuItem_Click(object sender, EventArgs e)
        {
            if (txtBox.Modified == true)
            {
                DialogResult dr = MessageBox.Show("文件发生变化，是否更改保存？", "注意", MessageBoxButtons.YesNoCancel);
                if (dr == DialogResult.Yes)
                {
                    保存SToolStripMenuItem_Click(sender, e);
                    return;
                }
                else if (dr == DialogResult.Cancel)
                {
                    return;
                }
                txtBox.Clear();
                this.Text = "NewNotepad";
            }
            else
            {
                txtBox.Clear();
                this.Text = "NewNotepad";
            }
        }
        private void 打开ToolStripMenuItem_Click(object sender, EventArgs e)
        {
            if (openFileDialog.ShowDialog() == DialogResult.OK)
            {
                filename = openFileDialog.FileName;
                OpenFile();
            }
        }
        protected void OpenFile()
        {
            try
            {
                txtBox.Clear();
                txtBox.Text = File.ReadAllText(filename);
            }
            catch
            { MessageBox.Show("Error!"); }
        }
        private void 保存SToolStripMenuItem_Click(object sender, EventArgs e)
        {
            try
            {
                StreamWriter sw = File.AppendText(Application.ExecutablePath);
                sw.Write(txtBox.Text);
                sw.Dispose();
            }
            catch
            {
                SaveFileDialog sf = new SaveFileDialog();
                sf.DefaultExt = "*.txt";
                sf.Filter = "文本文档(.txt)|*.txt";
                if (sf.ShowDialog() == DialogResult.OK)
                {
                    StreamWriter sw = File.AppendText(sf.FileName);
                    sw.Write(txtBox.Text);
                    sw.Dispose();
                }
            }
        }
        private void 另存为ToolStripMenuItem_Click(object sender, EventArgs e)
        {
            string name;
            //SaveFileDialog类
            SaveFileDialog save = new SaveFileDialog();
            //过滤器
            save.Filter = "*.txt|*.TXT|(*.*)|*.*";
            //显示
            if (save.ShowDialog() == DialogResult.OK)
            {
                name = save.FileName;
                FileInfo info = new FileInfo(name);
                //info.Delete();
                StreamWriter writer = info.CreateText();
                writer.Write(txtBox.Text);
                writer.Close();
            }
        }
        private void 页面设置ToolStripMenuItem_Click(object sender, EventArgs e)
        {
            //弹出页面设置界面
            pageSetupDialog.Document = printDocument;
            pageSetupDialog.ShowDialog();
        }
        private void 打印PToolStripMenuItem_Click(object sender, EventArgs e)
        {
            //显示允许用户选择打印机的选项及其它打印选项的对话框
            this.printDialog.Document = this.printDocument;
            this.printDialog.PrinterSettings = this.pageSetupDialog.PrinterSettings;
            //向打印机发送打印指令
            if (this.printDialog.ShowDialog() == DialogResult.OK)
            {
                try
                {
                    this.printDocument.Print();
                }
                catch (Exception ex)
                {
                    MessageBox.Show(ex.Message, "错误信息！", MessageBoxButtons.OK, MessageBoxIcon.Error);
                }
            }
        }
        private void 退出XToolStripMenuItem_Click(object sender, EventArgs e)
        {
            Application.Exit();
        }
        private void 编辑ToolStripMenuItem_Click(object sender, EventArgs e)
        {
            剪切ToolStripMenuItem.Enabled = txtBox.Modified;
            if (txtBox.SelectedText == "")
            {
                剪切ToolStripMenuItem.Enabled = false;
                复制ToolStripMenuItem.Enabled = false;
                删除ToolStripMenuItem.Enabled = false;
            }
            else
            {
                剪切ToolStripMenuItem.Enabled = true;
                复制ToolStripMenuItem.Enabled = true;
                删除ToolStripMenuItem.Enabled = true;
            }
            if (txtBox.Text == "")
            {
                查找ToolStripMenuItem.Enabled = false;
                查找下一个ToolStripMenuItem.Enabled = false;
                查找上一个ToolStripMenuItem.Enabled = false;
                替换ToolStripMenuItem.Enabled = false;
            }
            else
            {
                查找ToolStripMenuItem.Enabled = true;
                查找下一个ToolStripMenuItem.Enabled = true;
                查找上一个ToolStripMenuItem.Enabled = true;
                替换ToolStripMenuItem.Enabled = true;
            }
            if (Clipboard.GetText() == "")
                粘贴ToolStripMenuItem.Enabled = false;
            else
                粘贴ToolStripMenuItem.Enabled = true;
        }
        private void 撤销ToolStripMenuItem_Click(object sender, EventArgs e)
        {
            if (txtBox.CanUndo)
            {
                txtBox.Undo();
                txtBox.ClearUndo();
            }
        }
        private void 剪切ToolStripMenuItem_Click(object sender, EventArgs e)
        {
            txtBox.Cut();
        }
        private void 复制CToolStripMenuItem_Click(object sender, EventArgs e)
        {
            txtBox.Copy();
        }
        private void 粘贴PToolStripMenuItem_Click(object sender, EventArgs e)
        {
            txtBox.Paste();
        }
        private void 删除lToolStripMenuItem_Click(object sender, EventArgs e)
        {
            txtBox.SelectedText = string.Empty;
        }
        TextBox txtInput = new TextBox()
        {
            Font = new Font("宋体", 10)
        };
        TextBox txtInputReplace = new TextBox()
        {
            Font = new Font("宋体", 10)
        };
        Label lblSearch = new Label
        {
            Text = "查找内容：",
            Size = new Size(65, 25),
            Location = new Point(5, 22)
        };
        Label lblDirection = new Label
        {
            Text = "查找方向：",
            Size = new Size(65, 25),
            Location = new Point(5, 58)
        };
        Button FindNext = new Button
        {
            Name = "btnFindNext",
            Text = "查找下一项",
            Size = new Size(80, 25),
            Location = new Point(265, 15)
        };
        Button Cancel = new Button
        {
            Name = "btnCancel",
            Text = "取消",
            Size = new Size(80, 25),
            Location = new Point(265, 50)
        };
        RadioButton down = new RadioButton
        {
            Name = "radDown",
            Text = "向下",
            Size = new Size(55, 25),
            Location = new Point(70, 53),
            Checked = true
        };
        RadioButton upward = new RadioButton
        {
            Name = "radUpward",
            Text = "向上",
            Size = new Size(55, 25),
            Location = new Point(140, 53),
            Checked = false
        };
        new Form FindForm = new Form
        {
            Text = "查找文本",
            FormBorderStyle = FormBorderStyle.FixedSingle,
            MaximizeBox = false,
            MinimizeBox = false
        };
        private void 查找ToolStripMenuItem_Click(object sender, EventArgs e)
        {
            //显示查找对话框
            txtInput.Size = new Size(190, 33);
            txtInput.Location = new Point(70, 15);
            txtInput.Multiline = true;

            FindNext.Click += new EventHandler(Direction_Click);
            //FindNext.Click += new EventHandler(Visible_Click);

            Cancel.Click += new EventHandler(Cancel_Click);

            FindForm.Controls.Add(lblSearch);
            FindForm.Controls.Add(lblDirection);
            FindForm.Controls.Add(txtInput);
            FindForm.Controls.Add(down);
            FindForm.Controls.Add(upward);
            FindForm.Controls.Add(FindNext);
            FindForm.Controls.Add(Cancel);
            FindForm.Top = this.Top + 50;
            FindForm.Left = this.Left + 50;
            FindForm.Height = 120;
            FindForm.Width = 380;
            FindForm.StartPosition = FormStartPosition.CenterParent;
            FindForm.ShowDialog();
        }
        private void Visible_Click(object sender, EventArgs e)
        {
            FindForm.Visible = false;
        }
        private void Cancel_Click(object sender, EventArgs e)
        {
            //关闭对话框
            FindForm.Close();
            ReplaceForm.Close();
        }
        private void Direction_Click(object sender, EventArgs e)
        {
            //选择字符查找方向
            if (down.Checked == true)
            {
                Find_Click(sender, e);
            }
            else if (upward.Checked == true)
            {
                FindLast_Click(sender, e);
            }
        }
        int nextPosition, firstPosition;
        string word;
        Boolean IF = false;
        private void Find_Click(object sender, EventArgs e)
        {
            txtBox.Focus();
            FindWords(txtInput.Text);
        }
        private void FindWords(string words)
        {
            //向下查找字符
            if (nextPosition >= txtBox.Text.Length)
                nextPosition = 0;
            firstPosition = txtBox.Text.IndexOf(words, nextPosition);
            if (firstPosition == -1)
                nextPosition = 0;
            else
            {
                txtBox.Select(firstPosition, words.Length);
                nextPosition = firstPosition + 1;
            }
            word = words;
            IF = true;
        }
        private void 查找下一个ToolStripMenuItem_Click(object sender, EventArgs e)
        {
            //查找下一项，如果未查找过，则显示查找对话框
            down.Checked = true;
            upward.Checked = false;
            try
            {
                FindWords(word);
            }
            catch
            {
                查找ToolStripMenuItem_Click(sender, e);
            }
        }
        private void FindLast_Click(object sender, EventArgs e)
        {
            txtBox.Focus();
            FindWordsLast(txtInput.Text);
        }
        private void FindWordsLast(string words)
        {
            //向上查找字符
            if (IF == false)
                nextPosition = txtBox.Text.Length;
            if (nextPosition < 0)
                nextPosition = txtBox.Text.Length;

            firstPosition = txtBox.Text.LastIndexOf(words, nextPosition);

            if (firstPosition == -1)
                nextPosition = txtBox.Text.Length;
            else
            {
                txtBox.Select(firstPosition, words.Length);
                nextPosition = firstPosition - 1;
            }
            word = words;
            IF = true;
        }
        private void 查找上一个ToolStripMenuItem_Click(object sender, EventArgs e)
        {
            //查找上一项，如果未查找过，则显示查找对话框
            upward.Checked = true;
            down.Checked = false;
            try
            {
                FindWordsLast(word);
            }
            catch
            {
                查找ToolStripMenuItem_Click(sender, e);
            }
        }
        Label LblReplace = new Label
        {
            Name = "lblReplace",
            Text = "替换：",
            Size = new Size(55, 25),
            Location = new Point(15, 50)
        };
        Form ReplaceForm = new Form
        {
            Text = "替换文本",
            FormBorderStyle = FormBorderStyle.FixedSingle,
            MaximizeBox = false,
            MinimizeBox = false
        };
        private void 替换ToolStripMenuItem_Click(object sender, EventArgs e)
        {
            txtInput.Size = new Size(190, 30);
            txtInput.Location = new Point(70, 12);
            txtInput.Multiline = true;

            txtInputReplace.Size = new Size(190, 30);
            txtInputReplace.Location = new Point(70, 47);
            txtInputReplace.Multiline = true;

            Button Replace = new Button
            {
                Name = "btnReplace",
                Text = "替换",
                Size = new Size(80, 25),
                Location = new Point(265, 15)
            };
            Replace.Click += new EventHandler(Replace_Click);
            Cancel.Click += new EventHandler(Cancel_Click);

            ReplaceForm.Controls.Add(lblSearch);
            ReplaceForm.Controls.Add(LblReplace);
            ReplaceForm.Controls.Add(txtInput);
            ReplaceForm.Controls.Add(txtInputReplace);
            ReplaceForm.Controls.Add(Replace);
            ReplaceForm.Controls.Add(Cancel);
            ReplaceForm.Top = this.Top + 50;
            ReplaceForm.Left = this.Left + 50;
            ReplaceForm.Height = 140;
            ReplaceForm.Width = 380;
            ReplaceForm.StartPosition = FormStartPosition.CenterParent;
            ReplaceForm.ShowDialog();
        }
        private void Replace_Click(object sender, EventArgs e)
        {
            txtBox.Text = txtBox.Text.Replace(txtInput.Text, txtInputReplace.Text);
        }
        private void 全选AToolStripMenuItem_Click(object sender, EventArgs e)
        {
            txtBox.SelectAll();
        }
        private void 自动换行ToolStripMenuItem_Click(object sender, EventArgs e)
        {
            //默认自动换行，点击按钮打开或关闭自动换行
            if (自动换行ToolStripMenuItem.Checked == true)
            {
                txtBox.WordWrap = false;
                自动换行ToolStripMenuItem.Checked = false;
            }
            else
            {
                txtBox.WordWrap = true;
                自动换行ToolStripMenuItem.Checked = true;
            }
        }
        private void 字体ToolStripMenuItem_Click(object sender, EventArgs e)
        {
            //提示用户从本地计算机安装的字体中选择字体字号
            FontDialog fontDialog = new FontDialog();
            if (fontDialog.ShowDialog() == DialogResult.OK)
            {
                txtBox.Font = fontDialog.Font;
            }
        }
        private void Form1_SizeChanged(object sender, EventArgs e)
        {
            //窗体的txtBox控件随窗体改变而改变的大小
            if (状态栏ToolStripMenuItem.Checked == true && 工具栏TToolStripMenuItem.Checked == true)
                txtBox.Height = this.Height - menuStrip.Height - toolStrip.Height - statusStrip.Height - 39;
            else if (状态栏ToolStripMenuItem.Checked == false && 工具栏TToolStripMenuItem.Checked == true)
                txtBox.Height = this.Height - menuStrip.Height - toolStrip.Height - 39;
            else if (状态栏ToolStripMenuItem.Checked == true && 工具栏TToolStripMenuItem.Checked == false)
                txtBox.Height = this.Height - menuStrip.Height - statusStrip.Height - 39;
            else
                txtBox.Height = this.Height - menuStrip.Height - 39;
            txtBox.Width = this.Width - 16;
        }
        private void 工具栏TToolStripMenuItem_Click(object sender, EventArgs e)
        {
            //默认打开工具栏，点击按钮打开或关闭工具栏
            if (工具栏TToolStripMenuItem.Checked == true)
            {
                toolStrip.Visible = false;
                工具栏TToolStripMenuItem.Checked = false;
                txtBox.Top = 25;
            }
            else if (工具栏TToolStripMenuItem.Checked == false)
            {
                toolStrip.Visible = true;
                工具栏TToolStripMenuItem.Checked = true;
                txtBox.Top = 50;
            }
            Form1_SizeChanged(sender, e);
        }
        private void 放大ToolStripMenuItem_Click(object sender, EventArgs e)
        {
            //放大字体大小
            var fontsize = txtBox.Font.Size;
            var fontFamily = txtBox.Font.FontFamily;
            txtBox.Font = new Font(fontFamily, fontsize + 1);
        }
        private void 缩小ToolStripMenuItem_Click(object sender, EventArgs e)
        {
            //缩小字体大小
            var fontsize = txtBox.Font.Size;
            var fontFamily = txtBox.Font.FontFamily;
            txtBox.Font = new Font(fontFamily, fontsize - 1);
        }
        private void 恢复默认缩放ToolStripMenuItem_Click(object sender, EventArgs e)
        {
            //恢复默认字体大小
            txtBox.Font = new Font(txtBox.Font.FontFamily, 11);
        }
        private void 状态栏ToolStripMenuItem_Click(object sender, EventArgs e)
        {
            //默认显示状态栏，点击按钮显示或关闭状态栏
            if (状态栏ToolStripMenuItem.Checked == true)
            {
                statusStrip.Visible = false;
                状态栏ToolStripMenuItem.Checked = false;
            }
            else if (状态栏ToolStripMenuItem.Checked == false)
            {
                statusStrip.Visible = true;
                状态栏ToolStripMenuItem.Checked = true;
            }
            Form1_SizeChanged(sender, e);
        }
        //private int GetStringLen(string s)
        //{
        //    if (!string.IsNullOrEmpty(s))
        //    {
        //        int len = s.Length;
        //        for (int i = 0; i < s.Length; i++)
        //        {
        //            if (s[i] > 255)
        //                len++;
        //        }
        //        return len;
        //    }
        //    return 0;
        //}
        private void 查看帮助HToolStripMenuItem_Click(object sender, EventArgs e)
        {
            //调用系统自带的浏览器打开网页查看帮助
            Process.Start("https://jingyan.baidu.com/article/a24b33cdd86a0f19fe002be9.html");
        }
        private void 关于记事本ToolStripMenuItem_Click(object sender, EventArgs e)
        {
            //关于记事本说明
            Label lblTitle = new Label()
            {
                Text = "多功能记事本",
                Size = new Size(150, 25),
                Location = new Point(100, 50)
            };
            Label lblEdition = new Label()
            {
                Text = "版本号：个性测试版",
                Size = new Size(150, 25),
                Location = new Point(85, 100)
            };
            Label lblMail = new Label()
            {
                Text = "E-Mail：",
                Size = new Size(55, 25),
                Location = new Point(30, 180)
            };
            LinkLabel llblMail = new LinkLabel()
            {
                Text = "2417525822@qq.com",
                Size = new Size(110, 25),
                Location = new Point(85, 180)
            };
            Label lblCNDS = new Label()
            {
                Text = "CNDS博客：",
                Size = new Size(65, 25),
                Location = new Point(20, 220)
            };
            LinkLabel llblCNDS = new LinkLabel()
            {
                Text = "https://blog.csdn.net/UFO_Harold",
                Size = new Size(200, 25),
                Location = new Point(85, 220)
            };
            Form about = new Form
            {
                Text = "关于记事本",
                FormBorderStyle = FormBorderStyle.FixedSingle,
                MaximizeBox = false
            };

            llblCNDS.Click += new EventHandler(LlblCNDS_Click);
            about.Controls.Add(lblTitle);
            about.Controls.Add(lblEdition);
            about.Controls.Add(lblMail);
            about.Controls.Add(llblMail);
            about.Controls.Add(lblCNDS);
            about.Controls.Add(llblCNDS);
            about.Top = this.Top + this.Height / 2 - about.Height / 2;
            about.Left = this.Left + this.Width / 2 - about.Width / 2;
            about.StartPosition = FormStartPosition.CenterParent;
            about.ShowDialog();
        }
        private void LlblCNDS_Click(object sender, EventArgs e)
        {
            Process.Start("https://blog.csdn.net/UFO_Harold");
        }
        private void 新建toolStripButton_Click(object sender, EventArgs e)
        {
            新建NToolStripMenuItem_Click(this, e);
        }
        private void 另存为toolStripButton_Click(object sender, EventArgs e)
        {
            另存为ToolStripMenuItem_Click(this, e);
        }
        private void 保存StoolStripButton_Click(object sender, EventArgs e)
        {
            保存SToolStripMenuItem_Click(this, e);
        }
        private void 打印PtoolStripButton_Click(object sender, EventArgs e)
        {
            打印PToolStripMenuItem_Click(this, e);
        }
        private void 剪切toolStripButton_Click(object sender, EventArgs e)
        {
            剪切ToolStripMenuItem_Click(this, e);
        }
        private void 复制CtoolStripButton_Click(object sender, EventArgs e)
        {
            复制CToolStripMenuItem_Click(this, e);
        }
        private void 粘贴PtoolStripButton_Click(object sender, EventArgs e)
        {
            粘贴PToolStripMenuItem_Click(this, e);
        }
        private void 帮助HtoolStripButton_Click(object sender, EventArgs e)
        {
            查看帮助HToolStripMenuItem_Click(this, e);
        }
        private void Timer_Tick(object sender, EventArgs e)
        {
            //显示编辑光标所在几行几列
            int row = txtBox.GetLineFromCharIndex(txtBox.SelectionStart) + 1;
            int col = (txtBox.SelectionStart - txtBox.GetFirstCharIndexFromLine(txtBox.GetLineFromCharIndex(txtBox.SelectionStart))) + 1;
            toolStripStatusLblLocation.Text = "第 " + row + " 行, 第 " + col + " 列";
            toolStripStatusLblNow.Text = "" + DateTime.Now.ToLocalTime();
        }
        private void Form1_FormClosing(object sender, FormClosingEventArgs e)
        {
            //关闭窗体时如果已修改内容，则弹出是否保存对话框，否则直接关闭窗体
            if (txtBox.Modified == true)
            {
                DialogResult dr = MessageBox.Show("文件发生变化，是否更改保存？", "注意", MessageBoxButtons.YesNoCancel);
                if (dr == DialogResult.Yes)
                {
                    保存SToolStripMenuItem_Click(sender, e);
                    return;
                }
                else if (dr == DialogResult.No)
                {
                    return;
                }
                else if (dr == DialogResult.Cancel)
                {
                    e.Cancel = true;
                }
            }
        }
    }
}

运行结果

注：

1. 控件请自行改名，也可使用默认控件名，此次程序的控件均已自定义名称，然后再双击控件便会自动创建控件的事件函数并跳到代码页，全数copy代码到自己新建的程序可能运行不起来，因为控件的事件需要双击控件才跳转到事件函数，事件方法前出现引用不是为 0 即生效；
2. 查找上一项下一项功能混用时会有一些bug，达不到预期效果，但能运行，不会报错，一点逻辑上的问题，目前没有想到解决方法，大家可自行深入摸索，如有可以改进的地方可联系博主；
3. 整个项目源码的文件：（源码仅供学习交流使用，如需使用请安装.NET Framework 4.7.2框架，且图标可能因文件路径不同而无法显示，修改文件路径即可）

• 蓝奏云：https://www.lanzous.com/i9r643e
• 百度网盘：https://pan.baidu.com/s/1BagLHS9bOG2jvaOcHgeUgA 提取码：y639
• Github：https://github.com/Harold-666/Notepad/tree/master

该文是从CSND搬家过来的文章，已修正，觉得CSND不好用，搬至博客园在此安家，总的来说，在博客园的体验感比在CSDN好很多，往后请各位博友多多指教！我的博客园地址：https://www.cnblogs.com/Harold-popo

• 状态栏图标设置

• 项目文件目录