光标滚动富文本框时停止计时器

Question

我正在使用一个 timer1，它在光标位于富文本框内时停止，所以我已经尝试了一些事件，例如鼠标输入、鼠标按下和获得焦点以停止计时器，但是当我在滚动富文本框。 当光标位于富文本框内时，哪个事件允许我滚动并关闭计时器 1？ 谢谢

Answer 1

似乎没有简单的单事件方法来做到这一点。正如您所发现的，单击滚动条时没有Enter 或MouseEnter 事件。我认为以下应该做你想做的事情：

Private isScrollingRtb As Boolean = False

Private Sub RichTextBox1_Enter(sender As Object, e As EventArgs) Handles RichTextBox1.Enter
    'The RTB received focus.
    Timer1.Stop()
End Sub

Private Sub RichTextBox1_Leave(sender As Object, e As EventArgs) Handles RichTextBox1.Leave
    'The RTB lost focus.
    Timer1.Start()
End Sub

Private Sub RichTextBox1_VScroll(sender As Object, e As EventArgs) Handles RichTextBox1.VScroll
    If Not ActiveControl Is RichTextBox1 Then
        'The user scrolled the RTB while it did not have focus.
        Timer1.Stop()
        isScrollingRtb = True
    End If
End Sub

Private Sub Form1_MouseEnter(sender As Object, e As EventArgs) Handles Me.MouseEnter
    If isScrollingRtb Then
        'The user left the RTB after scrolling it without focus.
        Timer1.Start()
        isScrollingRtb = False
    End If
End Sub

当用户单击滚动条时，会引发VScroll 事件，因此您可以在该事件上Stop Timer。问题是决定何时再次Start。在此示例中，我选择在鼠标指针下一次移到表单本身时这样做。