Private Sub CmdCalculate_Click()
Dim a, b, c, m, n As Integer
a = 1
b = 1
m = 2
n = TxtInput.Text2
Do
c = a + b
m = m + 1
a = b
b = c
Loop While c < n
LblResult.Caption = m
End Sub
Private Sub CmdExit_Click()
End
End Sub
Private Sub Form_Load()
TxtProblem.Text = "  有一对小兔子，长到第3个月时生出一对小兔子，以后每个月都生出一对小兔子，而所有出生的成对小兔子都和第一对兔子的繁殖规律相同。"
TxtProblem.Locked = True
TxtInput.Text2 = ""
LblResult.Caption = ""
End Sub
Private Sub TxtInput_KeyPress(Index As Integer, KeyAscii As Integer)
LblResult.Caption = ""
If KeyAscii < 0 Or KeyAscii > 9 Then KeyAscii = 0
End Sub
一运行就会出现
编译错误：
未找到方法或数据成员
调试，黄色箭头指向Private Sub Form_Load()这一行，请求大神，怎么改！~

看不懂程式在做啥～但是这样可以运行～

Option Explicit

Private Sub CmdCalculate_Click()
Dim a, b, c, m, n As Integer

    a = 1
    b = 1
    m = 2
    n = Val(TxtInput(0).Text)
    Do
        c = a + b
        m = m + 1
        a = b
        b = c
    Loop While c < n
    
    LblResult.Caption = m
    
End Sub

Private Sub CmdExit_Click()
    End
End Sub

Private Sub Form_Load()
    TxtProblem.Text = "  有一对小兔子，长到第3个月时生出一对小兔子，以后每个月都生出一对小兔子，而所有出生的成对小兔子都和第一对兔子的繁殖规律相同。"
    TxtProblem.Locked = True
    TxtInput(0).Text = ""
    LblResult.Caption = ""
End Sub

Private Sub TxtInput_KeyPress(Index As Integer, KeyAscii As Integer)
    LblResult.Caption = ""
'    If KeyAscii < 0 Or KeyAscii > 9 Then KeyAscii = 0
End Sub

万分感谢，照你做的改了，可以运行了，运行正常。万分感谢。

1、TxtInput.Text2 = ""   改为TxtInput=""
2、Private Sub TxtInput_KeyPress(Index As Integer, KeyAscii As Integer)去掉index，除非你用了控件数组，如果真用了控件数组，则前面关于TxtInput的用法都需要带上数组编号，即TxtInput（编号）。这一句应改为Private Sub TxtInput_KeyPress(KeyAscii As Integer)
3、If KeyAscii < 0 Or KeyAscii > 9 Then KeyAscii = 0这一句是想让文本框只能输入数字，因此方法错误，应改成对0和9的asc码的判断，这句改为If KeyAscii < Asc("0") Or KeyAscii > Asc("9") Then KeyAscii = 0
4、n = TxtInput.Text2  同样应改为n = TxtInput

附上做好的工程文件，关于小兔子的算法未考虑，你自己看看，希望早日入门

万分感谢，已经按照您说的分析，问题解决。

lowxiong是个大好人兼VB高手，让你知其然还让你知其所以然，我就曾得益于他的许多帮助。