在循环中显示特定结果

Question

我正在尝试创建一个能够使用 RSA 加密系统进行编码的程序。为此，我创建了能够使用Euclidean Algorithm 进行计算的代码。代码如下：

Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
    number1 = TextBox1.Text
    number2 = TextBox2.Text
    Do While answer <> 0
        answer = number1 Mod number2
        number2 = number1 And answer = number2
    Loop
    MessageBox.Show(answer)
End Sub

所以，这并不难，对吧？问题是它总是显示 0 作为答案，这是有道理的。但我想在最后一个之前得到循环的答案。

这是一个[示例]

如果你不明白我想说什么。

我希望有人能够帮助我:)

Answer 1

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As                                                            System.EventArgs) Handles Button2.Click
        dim prevAnswer as integer
        number1 = TextBox1.Text
        number2 = TextBox2.Text
        Do While answer <> 0
            prevAnswer = answer
            answer = number1 Mod number2
            number2 = number1 And answer = number2
        Loop
    MessageBox.Show(prevAnswer)
    End Sub

Answer 2

为什么不声明一个变量来保存答案并在设置它之前检查它是否为0？

Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As                                                            System.EventArgs) Handles Button2.Click
Dim number1
Dim number2
Dim answer
Dim whatIWant
    answer = -1
    number1 = TextBox1.Text
    number2 = TextBox2.Text
Do While answer <> 0    
    answer = number1 Mod number2
    number1 = number2
    number2 = answer        
    If answer <> 0 Then
        whatIWant = answer
    End If
Loop
MessageBox.Show (CStr(whatIWant))

End Sub

这是您可以在 Excel 中进行的一个简单测试，完成后消息框显示 99。

Sub TestIt()
Dim number1
Dim number2
Dim answer
Dim whatIWant
    answer = -1
    number1 = 148104 'TextBox1.Text
    number2 = 47223 'TextBox2.Text
Do While answer <> 0
    answer = number1 Mod number2
    number1 = number2
    number2 = answer

    If answer <> 0 Then
        whatIWant = answer
    End If
Loop
MsgBox (CStr(whatIWant))

End Sub