VB里面简单计算机代码有什么错误
Private Sub Command1_Click()
opt = "+"
End Sub
Private Sub Command2_Click()
opt = "-"
End Sub
Private Sub Command3_Click()
opt = "*"
End Sub
Private Sub Command4_Click()
opt = "/"
End Sub
Private Sub Command5_Click()
Dim a, b, result As Double
a = Text1.Text
b = Text2.Text
Select Case opt
Case "+"
result = Val(a) + Val(b)
Case "-"
result = Val(a) - Val(b)
Case "*"
result = Val(a) * Val(b)
Case "/"
result = Val(a) / Val(b)
End Select
Text3.Text = result
End Sub
Private Sub Text1_Change()
End Sub
Private Sub Text2_Change()
End Sub
Private Sub Text3_Change()
End Sub
为什么第三个text里面的值总是0,向高手请教
