编写VB程序,实现如下功能:单击“生成密文”按钮Command2,在文本框Text3中产生与每个小写字母对应的密文(每个明文字母对应1个不重复的密文字母)。在文本框Text1中输入单词字符串,单击“加密”按钮Command1后,进行逐个字符加密,加密方法:在“明文”中找到相应字符,再得到明文对应位置的密文,并在文本框Text2中显示对应密文(运行效果如图所示)。实现上述功能的VB代码如下,请完善程序代码。
Dim m2 As String
Private Sub Command1_Click()
Dim flag(1 To 26) As Boolean
Dim num As Integer,t As Integer
Randomize
num = 1
Text3.Text = “”
For i = 1 To 26
flag(i) = False
Next i
Do While num <= 26
x = Int(Rnd * 26) + 97
If flag(t) = False Then
m2 = m2 + Chr(x)
num = num + 1
End If
Loop
Text3.Text = m2
End Sub
Private Sub Command2_Click()
Dim s As String, m As String, result As String
Dim k As String, c As Integer
s = Text1.Text
m = “abcdefghijklmnopqrstuvwxyz”
For i = 1 To Len(s)
k = Mid(s, i, 1)
If k >= ”A” And k <= “Z” Then
k = Chr(Asc(k) + 32)
End If
c = 1: continue = True
Do While
If k = Mid(m, c, 1) Then
continue = False
End If
c = c + 1
Loop
Next i
Text2.Text = result
End Sub