【iOS】利用block实现回调的示例

来源：互联网发布：js prop checked 编辑：程序博客网时间：2024/05/16 11:01

利用block完成回调，小demo一个。闲话少说，直接上代码了！O(∩_∩)O~

TestObject.h

#import <Foundation/Foundation.h>typedef void (^FinishBlock)(NSString *backStr);@interface TestObject : NSObject//能进行回调的方法- (void)playSomeTime:(FinishBlock)block;@end

TestObject.m

#import "TestObject.h"@implementation TestObject- (void)playSomeTime:(FinishBlock)block{        for (int i = 0; i< 5000; i++) {        NSLog(@"i===%d",i);    }    block(@"被回调的字符串O(∩_∩)O~");}@end

ViewController.h

#import <UIKit/UIKit.h>@interface ViewController : UIViewController@end

ViewController.m

#import "ViewController.h"#import "TestObject.h"@interface ViewController ()@end@implementation ViewController- (void)viewDidLoad{    [super viewDidLoad];    TestObject *obj = [[TestObject alloc] init];    [obj playSomeTime:^(NSString *backStr){        NSLog(@"回调完成，被返回的结果===%@",backStr);    }];    NSLog(@"这是同步操作，需要等待回调完成");}- (void)didReceiveMemoryWarning{    [super didReceiveMemoryWarning];}@end

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