Block使用总结

• Block局部变量

  returnType (^blockName)(parameterTypes) = ^returnType(parameters) {...};如：int (^sum)(int,int) = ^int(int num1,int num2){    return num1+num2;};

• Block作为属性

  @property (nonatomic, copy, nullability) returnType (^blockName)(parameterTypes);       如：@property (nonatomic,copy) int (^sum)(int,int);

• Block作为方法参数

  - (void)someMethodThatTakesABlock:(returnType (^nullability)(parameterTypes))blockName;如：-(void)cal:(int (^)(int,int))sum{}   

• Block作为参数让方法调用

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

• Block typedef

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

  参考文档