影响keyData的ProcessCmdKey处理的断点

有人能解释为什么在ProcessCmdKey方法中按下Alt+右箭头键时会触发对Alt+左箭头键的检查吗?当我最初编写这个方法时,一切都正常工作。我开始质疑我所有的密钥处理程序,但想知道是否有很好的解释,或者我是否遗漏了什么。所有其他组合键都按预期工作。

Protected Overrides Function ProcessCmdKey(ByRef msg As Message, ByVal keyData As Keys) As Boolean
    If (keyData And Keys.Alt) = Keys.Alt Then
        If (keyData And Keys.Left) = Keys.Left Then
            'when Alt+Right key is pressed
            '   this executes, except when a breakpoint is set anywhere within this method
            '   this still executes in released code
            Debug.WriteLine("WTF!")
        End If
    End If
    Return MyBase.ProcessCmdKey(msg, keyData)
End Function

If keyData = (Keys.Alt Or Keys.Left) Then

[更新]

? convert.ToString(Keys.Left, 2)
"100101"
? convert.ToString(Keys.Right,2)
"100111"

仍然想知道为什么点击断点会改变行为。

[更新]