前端显示是指某个
程序窗口始终
置顶，也就是说这程序
窗口打开后，不管你再点击什么，它都不会被掩盖，始终显示在前面。
VB的前端显示（置顶）源码
Private Const a& = -1 '
置顶Private Const b& = &H1
Private Const c& = &H2
Private Const d& = -2 '正常
Private Sub Form_Load()
SetWindowPos Me.hWnd, a, 0, 0, 0, 0, b Or c
End Sub
'Checkbox的值
Private Sub Check1_Click()
If Check1.Value = 2 Then SetWindowPos Me.hWnd, a, 0, 0, 0, 0, b Or c
If Check1.Value = 1 Then SetWindowPos Me.hWnd, a, 0, 0, 0, 0, b Or c
If Check1.Value = 0 Then SetWindowPos Me.hWnd, d, 0, 0, 0, 0, b Or c
End Sub