如何在字母(凯撒密码)中增加字符串3个字母? [英] How to advance string 3 letters in the alphabet (Caesar cipher)?
问题描述
我正在尝试编写一个对用户提交的字符串进行加密的程序.我想使用一种加密技术,其中字符串在字母中高级3个字母.
例如: abc
将成为 def
.
目前,我有一个TextBox( TextBox1
)和一个按钮( Button1
).
到目前为止,我的代码:
I'm trying to make a program that encrypts a string the user submits. I want to use an encryption technique where the string is advanced 3 letters in the alphabet.
Example: abc
would become def
.
Currently I have a TextBox (TextBox1
) and a Button (Button1
).
My code so far:
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim rawText As String
rawText = TextBox1.Text
Dim letterTxt As String = Chr(Asc(rawText) + 3)
MsgBox(letterTxt)
End Sub
问题是当我运行它时,它只输出1个字母.
我做错了什么?
The problem is that when I run it, it only outputs 1 letter.
What did I do wrong?
推荐答案
一个凯撒密码方法.接受正向和负向移位以及(可选)多个字母.
后者将使用不同于通常的US-ASCII的ASCII表进行测试.
A Caesar cipher method. Accepts positive and negative shifts and, optionally, a number of alphabet letters.
The latter, to be tested with ASCII tables different than the usual US-ASCII.
它不会更改数字(略过),但是您可以根据需要使用相同的模式进行修改.
It doesn't alter digits (skipped) but you can modify it using the same pattern, if needed.
使用 Scramble
参数选择加扰(True)或不加扰(False).
Use the Scramble
parameter to select scramble (True) or unscramble (False).
示例测试代码:
Dim Scrambled1 As String = CaesarCipher("ABCXYZabcxyz", 3, True)
Dim Scrambled2 As String = CaesarCipher("ABCXYZabcxyz", -5, True)
'Scrambled1 is now DEFABCdefabc
'Scrambled2 is now VWXSTUvwxstu
Dim Unscrambled As String = CaesarCipher(Scrambled2, -5, false)
'Unscrambled is now ABCXYZabcxyz
Function CaesarCipher(Input As String, CaesarShift As Integer, Scramble As Boolean, Optional AlphabetLetters As Integer = 26) As String
Dim CharValue As Integer
Dim MinValue As Integer = AscW("A"c)
Dim MaxValue As Integer = AscW("Z"c)
Dim ScrambleMode As Integer = If((Scramble), 1, -1)
Dim output As StringBuilder = New StringBuilder(Input.Length)
If Math.Abs(CaesarShift) >= AlphabetLetters Then
CaesarShift = (AlphabetLetters * Math.Sign(CaesarShift)) - Math.Sign(CaesarShift)
End If
For Each c As Char In Input
CharValue = AscW(c)
If Not Char.IsNumber(c) Then
CharValue = CharValue + (CaesarShift * ScrambleMode) Mod AlphabetLetters
CharValue = If(AscW(Char.ToUpper(c)) + (CaesarShift * ScrambleMode) > MaxValue, CharValue - AlphabetLetters, CharValue)
CharValue = If(AscW(Char.ToUpper(c)) + (CaesarShift * ScrambleMode) < MinValue, CharValue + AlphabetLetters, CharValue)
End If
output.Append(ChrW(CharValue))
Next
Return output.ToString()
End Function
这篇关于如何在字母(凯撒密码)中增加字符串3个字母?的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!