1：新建類繼承UIButton
2：在.m文件粘貼以下代碼
- (BOOL)pointInside:(CGPoint)point withEvent:(UIEvent*)event
{
CGRect bounds = self.bounds;
//若原熱區小于44x44，則放大熱區，否則保持原大小不變
CGFloat widthDelta = MAX(44.0 - bounds.size.width, 0);
CGFloat heightDelta = MAX(44.0 - bounds.size.height, 0);
bounds = CGRectInset(bounds, -0.5 * widthDelta, -0.5 * heightDelta);
return CGRectContainsPoint(bounds, point);
}
3：收工。
