當按鈕超過了父檢視範圍，點選是沒有反應的。因為訊息的傳遞是從最下層的父檢視開始呼叫hittest方法。

- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event {
    UIView *view = [super hitTest:point withEvent:event];
    return view;
}

<span style="font-family:FangSong_GB2312;font-size:18px;">- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event {
    UIView *view = [super hitTest:point withEvent:event];
    if (view == nil) {
        CGPoint tempoint = [yourBtn convertPoint:point fromView:self];
        if (CGRectContainsPoint(yourBtn.bounds, tempoint))
        {
            view = yourBtn;
        }
    }
    return view;
}</span>