iOS复选框

        _workBtn = [UIButton buttonWithType:UIButtonTypeCustom];
        [_workBtn setImage:[UIImage imageNamed:@"xuanxiang_hui"] forState:UIControlStateNormal];
        [_workBtn setImage:[UIImage imageNamed:@"xuanxiang_lv"] forState:UIControlStateSelected];
        [self.contentView addSubview:_workBtn];
        [_workBtn mas_makeConstraints:^(MASConstraintMaker *make) {
            make.right.equalTo(workLB.left).offset(-6);
            make.size.equalTo(CGSizeMake(17, 17));
            make.centerY.equalTo(self.centerY);
        }];
        _workBtn.selected = YES;