VB简单问题，高手帮忙

来源：百度知道 编辑：UC知道 时间：2024/07/06 22:54:10
我想用下面的代码，让窗体的背景色循环变化，为什么不成功？我想可能是循环太快了，看不出变化，于是我用sleep函数，还是不行。
高手帮忙修改一下！注：只用循环实现，不用timer！

回答成功，即可送分，示谢！

Option Explicit
Private Declare Sub Sleep Lib "kernel32" (ByVal dwMilliseconds As Long)

Private Sub Command1_Click()
Dim i As Integer
For i = 1 To 8
If i Mod 2 = 1 Then Me.BackColor = vbBlack Else Me.BackColor = vbWhite
Sleep 1000
Next
End Sub

Private Sub Form_Load()
Me.BackColor = vbWhite
End Sub

试过了可以的。
Option Explicit
Private Declare Sub Sleep Lib "kernel32" (ByVal dwMilliseconds As Long)

Private Sub Command1_Click()
Dim i As Integer
For i = 1 To 8
If i Mod 2 = 1 Then Me.BackColor = vbBlack Else Me.BackColor = vbWhite
Sleep 1000
DoEvents '加上这个吧，释放系统资源，不然在单核CPU系统里面会看不到效果
Next
End Sub

Private Sub Form_Load()
Me.BackColor = vbWhite
End Sub

不知道你想要怎么变，用For来改变效果不明显，建议用Timer控件定时切换。
Option Explicit
Dim runInt As Integer

Private Sub Command1_Click()
Timer1.Enabled = Not Timer1.Enabled
End Sub

Private Sub Form_Load()
Me.BackColor = vbWhite
Timer1.Enabled = False
Timer1.Interval = 100
End Sub

Private Sub Timer1_Timer()
If runInt Mod 2 = 1 Then Me.BackColor = vbBlack Else Me.BackColor = vbWhite
If runInt < 8 Then runInt = runInt + 1 Else runInt = 1
End Sub

转移控制权最好不要乱用,特别是在大的循