给View1的maskView 赋值View2
1.View2不会显示在View1上;
2.View2 的alpha通道会体现在View1上。
关于maskView,Apple的解释:
An optional view whose alpha channel is used to mask a view’s content.
给View1的maskView 赋值View2
1.View2不会显示在View1上;
2.View2 的alpha通道会体现在View1上。
关于maskView,Apple的解释:
An optional view whose alpha channel is used to mask a view’s content.