181，加遮罩和将所需要的控件移到遮罩前面

@property (nonatomic,strong)UIButton *cover;

-(UIButton *)cover{

    if (_cover ==nil) {

        _cover = [[UIButtonalloc]initWithFrame:self.view.bounds];

        _cover.backgroundColor = [UIColorcolorWithWhite:0alpha:0.5];

        _cover.alpha =0;

        [self.viewaddSubview:_cover];

        [_cover addTarget:selfaction:@selector(changeIconSize:)

         forControlEvents:UIControlEventTouchUpInside];

    }

    return _cover;

}

- (IBAction)changeIconSize:(UIButton *)sender {

    //遮罩点击事件的内容

}

//将showIcon控件移到最前面

[self.viewbringSubviewToFront:self.showIcon];