UIImageView初始化

({

        UIImageView *imgView = [[UIImageViewalloc]init];

        imgView.image = [UIImageimageNamed:@"iphone_5.png"];

        

        [selfaddSubview:imgView];

        [imgView mas_makeConstraints:^(MASConstraintMaker *make) {

            make.size.mas_equalTo(CGSizeMake(45,45));

            make.centerX.equalTo(self.mas_centerX);

            make.top.equalTo(self.mas_top).with.offset(13*AUTOY);

        }];

        imgView;

    });