VB.NET，form 鼠标键盘消息为何无响应

VB.NET code

Private Sub MainForm_MouseMove(ByVal sender As System.Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles MyBase.MouseMove        g_nTimerCount = 0   '鼠标移动就恢复计时    End Sub    Private Sub MainForm_MouseDown(ByVal sender As System.Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles MyBase.MouseDown        g_nTimerCount = 0    '鼠标点击就恢复计时    End Sub    Private Sub MainForm_KeyDown(ByVal sender As System.Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles MyBase.KeyDown        g_nTimerCount = 0   '键盘落下就恢复计时    End Sub

鼠标移动，键盘落下。
F9断点，没用

[解决办法]
if(Form1->Activeted)

Private Sub MainForm_MouseMove(ByVal sender As System.Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles MyBase.MouseMove
g_nTimerCount = 0 '鼠标移动就恢复计时
End Sub

Private Sub MainForm_MouseDown(ByVal sender As System.Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles MyBase.MouseDown
g_nTimerCount = 0 '鼠标点击就恢复计时
End Sub

Private Sub MainForm_KeyDown(ByVal sender As System.Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles MyBase.KeyDown
g_nTimerCount = 0 '键盘落下就恢复计时
End Sub


end if
[解决办法]
Form 上 KeyPreview 需要设为 true
[解决办法]
可以重载消息处理函数或者实现过滤接口