Block使用小笔记

匿名函数的写法着实让人难记

Swift的闭包演变过程可以看这篇文章

As a local variable:

returnType (^blockName)(parameterTypes) = ^returnType(parameters) {...};

void (^payFinishBlock)(BOOL finish) = ^(BOOL finish) {};

As a property:

@property (nonatomic, copy, nullability) returnType (^blockName)(parameterTypes);

@property (nonatomic, copy) void (^successBlock)();

As a method parameter:

- (void)someMethodThatTakesABlock:(returnType (^nullability)(parameterTypes))blockName;

handler:(void (^)(UIAlertView *alertView, NSInteger buttonIndex))block

handler:(void (^)(void))block

As an argument to a method call:

[someObject someMethodThatTakesABlock:^returnType (parameters) {...}];

As a typedef:

typedef returnType (^TypeName)(parameterTypes);

TypeName blockName = ^returnType(parameters) {...};