iOS开发 dispatch_block_t 简单的实现不带参数的回调函数

通常写一个不带参数的块回调函数是这样写的
在 .h 头文件中
定义类型

typedef void (^leftBlockAction)();

再定义一个回调函数

- (void)leftButtonAction:(leftBlockAction)leftBlock;

在 .m 文件中实现

- (void)leftButtonAction:(leftBlockAction)leftBlock{
    leftBlock();
}

今天要讲的是另一个高效率的方法
只要在 .h 头文件定义属性方法

/** 左边Item点击 */
@property (nonatomic, copy) dispatch_block_t leftItemClickBlock;
/** 右边Item点击 */
@property (nonatomic, copy) dispatch_block_t rightItemClickBlock;
/** 搜索按钮点击点击 */
@property (nonatomic, copy) dispatch_block_t searchButtonClickBlock;

在 .m 文件 扩展中申明

@interface ClassName ()
/* 左边Item */
@property (strong , nonatomic)UIButton *leftItemButton;
/* 右边Item */
@property (strong , nonatomic)UIButton *rightItemButton;
/* 搜索按钮 */
@property (strong , nonatomic)UIButton *searchButton;
@end

添加点击事件

    _leftItemButton = ({
        UIButton * button = [UIButton new];
        [button addTarget:self action:@selector(leftButtonItemClick) forControlEvents:UIControlEventTouchUpInside];
        button;
    });
    _rightItemButton = ({
        UIButton * button = [UIButton new];
        [button addTarget:self action:@selector(rightButtonItemClick) forControlEvents:UIControlEventTouchUpInside];
        button;
    });
    _searchButton = ({
        UIButton * button = [UIButton new];
        [button addTarget:self action:@selector(searchButtonClick) forControlEvents:UIControlEventTouchUpInside];
        button;
    });

并实现

#pragma 自定义右边导航Item点击
- (void)rightButtonItemClick {
    !_rightItemClickBlock ? : _rightItemClickBlock();
}

#pragma 自定义左边导航Item点击
- (void)leftButtonItemClick {
    
    !_leftItemClickBlock ? : _leftItemClickBlock();
}

#pragma mark - 搜索按钮点击
- (void)searchButtonClick
{
    !_searchButtonClickBlock ? : _searchButtonClickBlock();
}

现在就可以在控制器中调用

    MyView *alert = [[MyView alloc]init];
    alert.leftItemClickBlock = ^{
        NSLog(@"点击了左键");
    };
    alert.rightItemClickBlock = ^{
        NSLog(@"点击了右键");
    };
    alert.searchButtonClickBlock = ^{
        NSLog(@"点击了搜索");
    };

当然还有其他方法可以实现，只是个人认为该方法比较好用。