Question

vb label.caption的基本问题

Private Sub Form_Load()
a = 1
End Sub
Private Sub Command1_Click()
Label1.Caption = a
End Sub

为何在label1中显示不到a的值1.?

Answer 1

Option Explicit
Dim A As Integer '加上这一句

Private Sub Form_Load()
a = 1 '这儿a默认只能在form_load过程生效
End Sub
Private Sub Command1_Click()
Label1.Caption = a '这儿的a也默认只在command1_click过程里面查找，找不到这个变量，只能返回空值了
End Sub

Answer 2

Private Sub Command1_Click()
Dim a As Integer
a = 1
Label1.Caption = a
End Sub

Answer 3

Dim a As Integer
a = 1
Label1.Caption = a