:点击一个按钮，界面变红，再点击，界面变兰，如此反复

Public isRed As Boolean = False
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
If isRed Then
Me.BackColor = Color.Blue
isRed = False
Else
Me.BackColor = Color.Red
isRed = True
End If
End Sub

非常感谢