简单记事本的代码？

Dim BlnEdited As Boolean = False '定义一个逻辑变量查看文本是否被编辑过
    Dim StrFilePath As String  '定义一个字符串变量存放文件路径
    Dim BlnSaved As Boolean = False   '定义一个逻辑变量查看文本是否被保存过
    Private TargetPosition As Integer
    Dim sFind As String

    Private Sub FindText(ByVal start_at As Integer)
        Dim pos As Integer
        'Dim target As Integer

        pos = InStr(start_at, RichTextBox1.Text, sFind) '获取用户输入要查的字符串的位置
        If pos > 0 Then  '找到了匹配的字符串
            TargetPosition = pos
            RichTextBox1.SelectionStart = TargetPosition - 1 '找到的字符串的第一个位置
            RichTextBox1.SelectionLength = Len(sFind) '选中找到的字符串
            'text1.SetFocus()
        Else  '没有找到匹配的字符串
            MsgBox("没找到！")
            'text1.SetFocus()
            sFind = InputBox("请输入要查找的字·词： ", "查找内容", sFind)

        End If
    End Sub
    '编写FileSave()函数来实现保存文件操作
    Private Sub FileSave()  '定义一个没有返回值的函数
        FileOpen(1, StrFilePath, OpenMode.Output) '打开文件，并定义文件号为1
        PrintLine(1, RichTextBox1.Text) '用PrintLine()函数将文本内容写入文件
        FileClose(1)     '关闭文件
        BlnEdited = False  '保存完文件，设置文件为未改动状态
        BlnSaved = True   '表明文件已经保存过
    End Sub
    '编写SaveFile()函数来保存文件
    Private Function SaveFile() As Boolean   '定义一个返回值为逻辑类型的函数
        If BlnSaved = True Then
            FileSave() '调用FileSave()函数保存文件
            Return True
        Else     '如果文件没有被保存过，则表明还没有文件路径
            '设置文件类型
            SaveFileDialog1.Filter = "文本文件（*.txt）|*.txt|所有文件（*.*）|*.*"
            If SaveFileDialog1.ShowDialog() = Windows.Forms.DialogResult.Cancel Then
                Return False  '用户取消保存，则返回函数值为False
                Exit Function    '跳出函数
            Else
                StrFilePath = SaveFileDialog1.FileName
                FileSave()   '保存文件
                Return True
            End If
        End If
    End Function
    '编写FormClose()函数来进行关闭当前文件时的操作
    Private Function FormClose() As Boolean
        Dim StrClick As String   '定义变量用来返回MessageBox的返回值
        If BlnEdited = False Then
            Return True    '如果文件没有被修改，则返回True
        Else
            StrClick = MessageBox.Show("文件已经改变，是否保存？", "", MessageBoxButtons.YesNoCancel)
            If StrClick = DialogResult.Yes Then
                If SaveFile() = True Then
                    Return True   '如果用户将文件保存了，则返回True
                    Exit Function
                Else
                    Return False '如果用户没有保存文件，则返回False

                End If
            ElseIf StrClick = DialogResult.No Then
                Return True    '如果用户不保存文件，则返回True
            Else
                Return False  '如果用户取消操作，则返回False
            End If
        End If
    End Function
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        'If FormClose() = False Then
        mnucut.Enabled = False
        mnucopy.Enabled = False
        剪切TToolStripMenuItem.Enabled = False
        复制CToolStripMenuItem.Enabled = False
        删除DToolStripMenuItem.Enabled = False
        撤消UToolStripMenuItem.Enabled = False
        重做RToolStripMenuItem.Enabled = False
        红色RToolStripMenuItem.Enabled = False
        绿色GToolStripMenuItem.Enabled = False
        蓝色BToolStripMenuItem.Enabled = False
        黑色ToolStripMenuItem.Enabled = False
        'End If
    End Sub
    Private Sub 新建NToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles 新建NToolStripMenuItem.Click
        If FormClose() = False Then
            Exit Sub   '如果函数返回值为False，表明用户取消操作，则跳出该操作
        Else   '表明可以新建文件了
            BlnEdited = False
            RichTextBox1.Text = ""  '新建一个文件，并把文件设为未修改和无保存路径状态
            BlnEdited = False
        End If
    End Sub

    Private Sub 打开OToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles 打开OToolStripMenuItem.Click
        Dim StrOpentext As String = ""
        If FormClose() = False Then  '调用FormClose()函数进行判断
            Exit Sub
        Else
            OpenFileDialog1.Filter = "文本文件（*.txt）|*.txt|所有文件（*.*）|*.*"
            If OpenFileDialog1.ShowDialog = Windows.Forms.DialogResult.Cancel Then
                Exit Sub
            Else
                RichTextBox1.Text = "" '先把文本框中的文本清空
                StrFilePath = OpenFileDialog1.FileName
                FileOpen(1, StrFilePath, OpenMode.Binary)
                While Not EOF(1)
                    StrOpentext = StrOpentext + InputString(1, 1) '用while语句读入文件内容
                End While
                '注意，对于InputString函数，文件只能用Input或Binary方式打开
                FileClose(1)
                RichTextBox1.Text = StrOpentext
                BlnSaved = True   '文件已有路径
                BlnEdited = False

            End If
        End If
    End Sub

    Private Sub 保存SToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles 保存SToolStripMenuItem.Click
        SaveFile()
        'With SaveFileDialog1
        '    .Filter = "rtf文件|*.rtf|txt文件(*.txt)|*.txt"
        '    .Title = "输入要保存的文件"
        '    .DefaultExt = "rtf"
        '    If .ShowDialog = Windows.Forms.DialogResult.OK Then
        '        RichTextBox1.SaveFile(.FileName)
        '        Me.Text = .FileName
        '    End If
        'end with

    End Sub

    Private Sub 另存为AToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles 另存为AToolStripMenuItem.Click
        BlnEdited = False
        SaveFile()

    End Sub

    Private Sub 退出XToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles 退出XToolStripMenuItem.Click
        Me.Close()
      
    End Sub

    Private Sub 撤消UToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles 撤消UToolStripMenuItem.Click
        RichTextBox1.Undo()
        重做RToolStripMenuItem.Enabled = True

    End Sub

    Private Sub 重做RToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles 重做RToolStripMenuItem.Click
        RichTextBox1.Redo()
    End Sub

    Private Sub 剪切TToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles 剪切TToolStripMenuItem.Click
        RichTextBox1.Cut()
        
    End Sub

    Private Sub 复制CToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles 复制CToolStripMenuItem.Click
        RichTextBox1.Copy()
        粘贴PToolStripMenuItem.Enabled = True
    End Sub

    Private Sub 粘贴PToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles 粘贴PToolStripMenuItem.Click
        RichTextBox1.Paste()

    End Sub

    Private Sub 删除DToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles 删除DToolStripMenuItem.Click
        'RichTextBox1.Text = ""
        RichTextBox1.SelectedText = ""
    End Sub

    Private Sub 全选AToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles 全选AToolStripMenuItem.Click
        RichTextBox1.SelectAll()

    End Sub

    Private Sub 插入时间DToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles 插入时间DToolStripMenuItem.Click
        RichTextBox1.SelectedText = CStr(Now())
    End Sub

    Private Sub RichTextBox1_SelectionChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles RichTextBox1.SelectionChanged
        If RichTextBox1.SelectedText <> "" Then
            mnucut.Enabled = True
            mnucopy.Enabled = True
            剪切TToolStripMenuItem.Enabled = True
            复制CToolStripMenuItem.Enabled = True
            删除DToolStripMenuItem.Enabled = True

            红色RToolStripMenuItem.Enabled = True
            绿色GToolStripMenuItem.Enabled = True
            蓝色BToolStripMenuItem.Enabled = True
            黑色ToolStripMenuItem.Enabled = True
        Else
            mnucut.Enabled = False
            mnucopy.Enabled = False
            剪切TToolStripMenuItem.Enabled = False
            复制CToolStripMenuItem.Enabled = False
            删除DToolStripMenuItem.Enabled = False
            
            红色RToolStripMenuItem.Enabled = False
            绿色GToolStripMenuItem.Enabled = False
            蓝色BToolStripMenuItem.Enabled = False
            黑色ToolStripMenuItem.Enabled = False
        End If
        If RichTextBox1.Text <> "" Then
            撤消UToolStripMenuItem.Enabled = True
            '重做RToolStripMenuItem.Enabled = True
        Else
            撤消UToolStripMenuItem.Enabled = False
            '重做RToolStripMenuItem.Enabled = False
        End If
    End Sub

    Private Sub RichTextBox1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles RichTextBox1.TextChanged
        BlnEdited = True
        ToolStripStatusLabel1.Text = "文本长度" + CStr(RichTextBox1.Text.Length)


    End Sub

    Private Sub 格式OToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles 格式OToolStripMenuItem.Click

    End Sub

    Private Sub 查找ToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles 查找ToolStripMenuItem.Click
        sFind = InputBox("请输入要查找的字·词：", "查找内容", sFind)
        FindText(1)
    End Sub

    Private Sub 查找下一个NToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles 查找下一个NToolStripMenuItem.Click
        FindText(TargetPosition + 1)
    End Sub

    Private Sub 颜色CToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles 颜色CToolStripMenuItem.Click
        ColorDialog1.ShowDialog()
        RichTextBox1.ForeColor = ColorDialog1.Color
    End Sub
    Private Sub 字体FToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles 字体FToolStripMenuItem.Click
        If FontDialog1.ShowDialog = Windows.Forms.DialogResult.OK Then
            RichTextBox1.Font = FontDialog1.Font
        End If
    End Sub

    Private Sub New_toolbtn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles New_toolbtn.Click
        If FormClose() = False Then
            Exit Sub
        Else
            BlnEdited = False
            RichTextBox1.Text = ""
            BlnEdited = False
        End If

    End Sub

    Private Sub Open_toolbtn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Open_toolbtn.Click
        Dim StrOpentext As String = ""
        If FormClose() = False Then
            Exit Sub
        Else
            OpenFileDialog1.Filter = "文本文件（*.txt）|*.txt|所有文件（*.*）|*.*"
            If OpenFileDialog1.ShowDialog = Windows.Forms.DialogResult.Cancel Then
                Exit Sub
            Else
                RichTextBox1.Text = ""
                StrFilePath = OpenFileDialog1.FileName
                FileOpen(1, StrFilePath, OpenMode.Binary)
                While Not EOF(1)
                    StrOpentext = StrOpentext + InputString(1, 1)
                End While
                FileClose(1)
                RichTextBox1.Text = StrOpentext
                BlnSaved = True
                BlnEdited = False

            End If
        End If
    End Sub
    Private Sub Save_toolbtn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Save_toolbtn.Click
        SaveFile()
    End Sub

    Private Sub Copy_toolbtn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Copy_toolbtn.Click
        RichTextBox1.Copy()
    End Sub

    Private Sub Cut_toolbtn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Cut_toolbtn.Click
        RichTextBox1.Cut()
    End Sub

    Private Sub Past_toolbtn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Past_toolbtn.Click
        RichTextBox1.Paste()
    End Sub

    Private Sub Undo_toolbtn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Undo_toolbtn.Click
        RichTextBox1.Undo()
    End Sub

    Private Sub Find_toolbtn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Find_toolbtn.Click
        sFind = InputBox("请输入要查找的字·词：", "查找内容", sFind)
        FindText(1)
    End Sub
    Private Sub 红色RToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles 红色RToolStripMenuItem.Click
        RichTextBox1.SelectionColor = Color.Red
    End Sub

    Private Sub 绿色GToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles 绿色GToolStripMenuItem.Click
        RichTextBox1.SelectionColor = Color.Green
    End Sub

    Private Sub 蓝色BToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles 蓝色BToolStripMenuItem.Click
        RichTextBox1.SelectionColor = Color.Blue
    End Sub

    Private Sub 黑色ToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles 黑色ToolStripMenuItem.Click
        RichTextBox1.SelectionColor = Color.Black
    End Sub

    Private Sub ContextMenuStrip1_Opening(ByVal sender As System.Object, ByVal e As ) Handles ContextMenuStrip1.Opening

    End Sub

    Private Sub 文件FToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles 文件FToolStripMenuItem.Click

    End Sub

    Private Sub 编辑EToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles 编辑EToolStripMenuItem.Click

    End Sub

   
    Private Sub mnucut_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles mnucut.Click
        RichTextBox1.Cut()
        mnuPaste.Enabled = True
        剪切TToolStripMenuItem.Enabled = True
    End Sub

    Private Sub mnucopy_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles mnucopy.Click
        RichTextBox1.Copy()
        RichTextBox1.Enabled = True
        粘贴PToolStripMenuItem.Enabled = True

    End Sub

    Private Sub mnuPaste_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles mnuPaste.Click
        RichTextBox1.Paste()
    End Sub