Public Class Form1
    Inherits System.Windows.Forms.Form
    Dim strInput, Code, Record, c As String
    Dim i%, length%, iAsc%

#Region " Windows 窗體設計器生成的代碼 "

    Public Sub New()
        MyBase.New()

        '該調用是 Windows 窗體設計器所必需的。
        InitializeComponent()

        '在 InitializeComponent() 調用之后添加任何初始化

    End Sub

    '窗體重寫處置以清理組件列表。
    Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
        If disposing Then
            If Not (components Is Nothing) Then
                components.Dispose()
            End If
        End If
        MyBase.Dispose(disposing)
    End Sub

    'Windows 窗體設計器所必需的
    Private components As System.ComponentModel.IContainer

    '注意：以下過程是 Windows 窗體設計器所必需的
    '可以使用 Windows 窗體設計器修改此過程。
    '不要使用代碼編輯器修改它。
    Friend WithEvents Label1 As System.Windows.Forms.Label
    Friend WithEvents Button1 As System.Windows.Forms.Button
    Friend WithEvents Button2 As System.Windows.Forms.Button
    Friend WithEvents Button3 As System.Windows.Forms.Button
    Friend WithEvents TextBox1 As System.Windows.Forms.TextBox
    Friend WithEvents TextBox2 As System.Windows.Forms.TextBox
    Friend WithEvents TextBox3 As System.Windows.Forms.TextBox
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Me.Label1 = New System.Windows.Forms.Label()
        Me.Button1 = New System.Windows.Forms.Button()
        Me.Button2 = New System.Windows.Forms.Button()
        Me.Button3 = New System.Windows.Forms.Button()
        Me.TextBox1 = New System.Windows.Forms.TextBox()
        Me.TextBox2 = New System.Windows.Forms.TextBox()
        Me.TextBox3 = New System.Windows.Forms.TextBox()
        Me.SuspendLayout()
        '
        'Label1
        '
        Me.Label1.Location = New System.Drawing.Point(0, 8)
        Me.Label1.Name = "Label1"
        Me.Label1.TabIndex = 0
        Me.Label1.Text = "輸入字符串"
        '
        'Button1
        '
        Me.Button1.Font = New System.Drawing.Font("宋體", 9.0!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(134, Byte))
        Me.Button1.Location = New System.Drawing.Point(8, 32)
        Me.Button1.Name = "Button1"
        Me.Button1.Size = New System.Drawing.Size(48, 23)
        Me.Button1.TabIndex = 1
        Me.Button1.Text = "加密"
        '
        'Button2
        '
        Me.Button2.Font = New System.Drawing.Font("宋體", 9.0!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(134, Byte))
        Me.Button2.Location = New System.Drawing.Point(8, 64)
        Me.Button2.Name = "Button2"
        Me.Button2.Size = New System.Drawing.Size(48, 23)
        Me.Button2.TabIndex = 2
        Me.Button2.Text = "解密"
        '
        'Button3
        '
        Me.Button3.Font = New System.Drawing.Font("宋體", 9.0!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(134, Byte))
        Me.Button3.Location = New System.Drawing.Point(8, 96)
        Me.Button3.Name = "Button3"
        Me.Button3.Size = New System.Drawing.Size(48, 23)
        Me.Button3.TabIndex = 3
        Me.Button3.Text = "清屏"
        '
        'TextBox1
        '
        Me.TextBox1.Font = New System.Drawing.Font("宋體", 10.5!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(134, Byte))
        Me.TextBox1.Location = New System.Drawing.Point(72, 8)
        Me.TextBox1.Name = "TextBox1"
        Me.TextBox1.Size = New System.Drawing.Size(208, 23)
        Me.TextBox1.TabIndex = 4
        Me.TextBox1.Text = ""
        '
        'TextBox2
        '
        Me.TextBox2.Font = New System.Drawing.Font("宋體", 10.5!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(134, Byte))
        Me.TextBox2.Location = New System.Drawing.Point(72, 40)
        Me.TextBox2.Name = "TextBox2"
        Me.TextBox2.Size = New System.Drawing.Size(208, 23)
        Me.TextBox2.TabIndex = 5
        Me.TextBox2.Text = ""
        '
        'TextBox3
        '
        Me.TextBox3.Font = New System.Drawing.Font("宋體", 10.5!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(134, Byte))
        Me.TextBox3.Location = New System.Drawing.Point(72, 72)
        Me.TextBox3.Name = "TextBox3"
        Me.TextBox3.Size = New System.Drawing.Size(208, 23)
        Me.TextBox3.TabIndex = 6
        Me.TextBox3.Text = ""
        '
        'Form1
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(6, 14)
        Me.ClientSize = New System.Drawing.Size(292, 273)
        Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.TextBox3, Me.TextBox2, Me.TextBox1, Me.Button3, Me.Button2, Me.Button1, Me.Label1})
        Me.Name = "Form1"
        Me.Text = "Form1"
        Me.ResumeLayout(False)

    End Sub

#End Region

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

    End Sub

    Private Sub Button3_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button3.Click
        TextBox1.Text = ""
        TextBox2.Text = ""
        TextBox3.Text = ""
    End Sub

    Private Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button2.Click
        Dim strInput, Code, Record, c As String
        Dim i%, length%, iAsc%
        strInput = TextBox1.Text
        length = Len(RTrim(strInput))    '去掉字符串右邊的空格，求真正的長度
        Code = ""
        For i = 1 To length
            c = Mid$(strInput, i, 1)     '取第i個字符
            Select Case c
                Case "A" To "Z"          '大寫字母加序數(shù)5加密
                    iAsc = Asc(c) + 5
                    If iAsc > Asc("Z") Then iAsc = iAsc - 26 '加密后字母超過Z
                    Code = Code + Chr(iAsc)
                Case "a" To "z"
                    iAsc = Asc(c) + 5     '小寫字母加序數(shù)5加密
                    If iAsc > Asc("z") Then iAsc = iAsc - 26
                    Code = Code + Chr(iAsc)
                Case Else                  '當?shù)趇個字符為其他字符時不加密
                    Code = Code + c
            End Select
        Next i
        TextBox2.Text = Code               '顯示加密后的字符串
    End Sub
End Class