I-Cloud程式攻略

Imports System.Text

Public Class Form1

    Private Sub button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles button1.Click
        textBox2.Text = IsEncryptString(textBox1.Text, 10, True)
    End Sub
    Private Function IsEncryptString(ByVal EncryptString As String, ByVal offset As Integer, ByVal IsEncrypt As Boolean) As String
        Dim TempString As String = String.Empty
        '定義ASCII Code
        Dim acsii As Encoding = Encoding.ASCII
        '取出字串每一字元的ASCII碼
        For i As Integer = 0 To EncryptString.Length - 1
            Dim Data As Integer
            '1.取出字元的ASCII碼
            Dim DataByte As Byte() = acsii.GetBytes(EncryptString(i).ToString())
            '2.轉成整數
            Data = Convert.ToInt32(DataByte(0))

            '3.加入偏移數
            If IsEncrypt Then
                '加密定義偏移數
                Data = Data + offset
            Else
                '解密則將偏移數減回來
                Data = Data - offset
            End If

            '4.轉成Byte
            Dim DescByte As Byte() = New Byte(0) {}
            DescByte(0) = Convert.ToByte(Data)
            '5.取出ASCII碼的String
            TempString = TempString + acsii.GetString(DescByte)
        Next
        '回傳字串
        Return TempString
    End Function

    Private Sub button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles button2.Click
        If textBox2.Text <> "" Then
            textBox3.Text = IsEncryptString(textBox2.Text, 10, False)
        End If
    End Sub
End Class