一. 简述
在项目中, Block的链式编程肯定是会用到的. 如一些框架等.
而对于项目中一些自定义的工具或view, 在以下情况时:
- 1.可以包装完整
- 2.有多个属性可以设置
- 3.在项目中多处被用到
最好实现Block的链式编程, 如此对团队非常有好处.
注: block的链式, 即block有返回值, 且返回当前对象
二.举例
项目中需要自定义UINavigationBar, 符合上述3个条件.
- 1.设置只读的, 有返回值的
block属性
/** 设置下划线 */
@property (nonatomic, copy, readonly) YHNavigationBarView *(^setupUnderline)(void);
///左按钮图片
@property (nonatomic, copy, readonly) YHNavigationBarView *(^leftBtnImage)(UIImage *image);
///左按钮标题
@property (nonatomic, copy, readonly) YHNavigationBarView *(^leftBtnTitle)(NSString *title);
///右按钮图片
@property (nonatomic, copy, readonly) YHNavigationBarView *(^rightBtnImage)(UIImage *image);
///右按钮标题
@property (nonatomic, copy, readonly) YHNavigationBarView *(^rightBtnTitle)(NSString *title);
///标题按钮图片
@property (nonatomic, copy, readonly) YHNavigationBarView *(^titleBtnImage)(UIImage *image);
///标题按钮的标题
@property (nonatomic, copy, readonly) YHNavigationBarView *(^titleBtnTitle)(NSString *title);
- 2.重写
getter - 2.1
///设置下划线
- (YHNavigationBarView *(^)(void))setupUnderline{
return ^YHNavigationBarView *(void){
//下划线
UIView *underlineView = [UIView new];
underlineView.backgroundColor = [UIColor colorWithHexString:@"#EEEEEE"];
[self addSubview:underlineView];
[underlineView mas_makeConstraints:^(MASConstraintMaker *make) {
make.left.equalTo(self);
make.right.equalTo(self);
make.bottom.equalTo(self);
make.height.equalTo(@1);
}];
return self;
};
}
- 2.2
///左按钮图片
- (YHNavigationBarView *(^)(UIImage *))leftBtnImage{
return ^YHNavigationBarView *(UIImage *image){
[self.leftBtn setImage:image forState:UIControlStateNormal];
return self;
};
}
其它getter方法与以上两个方法类似, 就不浪费篇章了.
- 3.调用
- 3.1 eg1
self.navBar.setupLeftBackBtn(self, YHBackImgTypeBlack).setupUnderline().
setupRightPlayBtn(self, nil, navBarplayBtn, ^{
[UIViewController yh_fromCurrentShowingVcToDestionVc:[YHPlayMusicVc new]];
});
- 3.2 eg2
self.navBar.setupLeftBackBtn(self, YHBackImgTypeBlack).
setupTitleBtn(nil, @"修改昵称", nil);
- 3.3 注意循环引用
navBar.titleBtnAlpha(0).setupLeftBtn([UIImage imageNamed:@"nav_toolbar_back_white"], nil, ^{
[weakSelf.navigationController popViewControllerAnimated:YES];
}).setupRightBtn([UIImage imageNamed:@"nav_share_white"], nil, ^{
[weakSelf navRightButtonClick];
}).setupTitleBtn(nil, self.titleStr, nil);
