Objective-C学习笔记之block

//定义一个函数，传入block类型参数myBlock5

int fun(int (^myBlock5)(int a,int b))

{

return myBlock5(10,20);

}

int (^myBloak2)(int,int);

myBloak2 = ^(int a, int b){

return a+b;

};

//函数调用部分

NSLog(@"%d",fun(myBloak2));//以myBloak5传入的形参，myBloak2的实现方法进行计算

//内联    block格式

fun(^int(int a, int b) {

return a+b;

});

NSLog(@"%d", fun(^int(int a, int b) {

return a+b;

}));

//

typedef NSString* (^Myblock1)(NSString *a);//定义代码块类型

@interface Student : NSObject

-(NSString *)myBlock2:(NSString *)string andBlock:(Myblock1)block2;//方法调用代码块

@end

@implementation Student

-(NSString *)myBlock2:(NSString *)string andBlock:(Myblock1)block2

{

NSLog(@"调用代码块%@",string);//输出:调用代码块liuguan

return block2(string);//方法返回代码块的返回值

}

@end

实现部分：

Student *student = [[Student alloc] init];

NSLog(@"%@", [student myBlock2:@"liuguan" andBlock:^NSString *(NSString *a)

{

NSLog(@"我是%@",a);//输出:我是liuguan因为返回block2(string)

NSString *b = [@"123" stringByAppendingString:a];

return b;//输出:123liuguan

}

]

);