回传值问题，一直都是困扰初学者的问题，今写者 代理、通知、block 三者的回传值做了一个小小的总结，
Main.storyboard 视图：
通过代码分别创建三个代表 代理、通知、block 的按钮，点击相应的按钮，会将相应的文本传入文本框中显示出来
代码如下：
// GWFMyDelegateBlockNotyView.h
// 回传值 #import <UIKit/UIKit.h>
@class GWFMyDelegateBlockNotyView; //协议
@protocol GWFMyDelegateBlockNotyViewDelegate <NSObject> //定义代理方法
-(void)GWFMyDelegateBlockNotyView:(GWFMyDelegateBlockNotyView *)view andString:(NSString *)string andImage:(UIImage *)image; @end @interface GWFMyDelegateBlockNotyView : UIView //定义 id 属性
@property (nonatomic,weak) id <GWFMyDelegateBlockNotyViewDelegate> myDelegate; //添加 block 属性
@property (nonatomic,copy) void (^myBlock)(NSString *,UIImage *); @end
// GWFMyDelegateBlockNotyView.m
// 回传值 #import "GWFMyDelegateBlockNotyView.h"
#import "SVProgressHUD.h"
#import "MBProgressHUD+Ex.h" @implementation GWFMyDelegateBlockNotyView - (instancetype)init
{
self = [super init];
if (self) { #pragma ==================================== 代理传值按钮 //1.创建 delegateBtn
UIButton *deleBtn = [[UIButton alloc] initWithFrame:CGRectMake(, , , )];
//设置背景颜色
deleBtn.backgroundColor = [UIColor redColor];
//设置title
[deleBtn setTitle:@"代理传值" forState:UIControlStateNormal];
//设置 title 的颜色
[deleBtn setTitleColor:[UIColor blueColor] forState:UIControlStateNormal]; //添加到控制器上
[self addSubview:deleBtn]; //添加 deleBtn 的监听事件
[deleBtn addTarget:self action:@selector(deleBtnClick) forControlEvents:UIControlEventTouchUpInside]; #pragma ==================================== Block传值按钮 //2.创建 Block 按钮
UIButton *blockBtn = [[UIButton alloc] initWithFrame:CGRectMake(, , , )];
//设置背景颜色
blockBtn.backgroundColor = [UIColor greenColor];
//设置 title
[blockBtn setTitle:@"Block传值" forState:UIControlStateNormal];
//设置 title 的颜色
[blockBtn setTitleColor:[UIColor blueColor] forState:UIControlStateNormal]; //添加到控制器上
[self addSubview:blockBtn]; //添加 blockBtn 的监听事件
[blockBtn addTarget:self action:@selector(blockBtnClick) forControlEvents:UIControlEventTouchUpInside]; #pragma ==================================== 通知传值按钮 //3.创建 notyBtn
UIButton *notyBtn = [[UIButton alloc] initWithFrame:CGRectMake(, , , )];
//设置背景颜色
notyBtn.backgroundColor = [UIColor blueColor];
//设置 title
[notyBtn setTitle:@"通知传值" forState:UIControlStateNormal];
//设置 notyBtn 的 title 的颜色
[notyBtn setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal]; //添加到控制器上
[self addSubview:notyBtn]; //添加 notyBtn 的监听事件
[notyBtn addTarget:self action:@selector(notyBtnClick) forControlEvents:UIControlEventTouchUpInside]; }
return self;
} //实现按钮的点击事件
#pragma mark -------代理 -(void)deleBtnClick {
NSString *myText = @"这是代理传来的值";
UIImage *image = [UIImage imageNamed:@"0 (3)"]; //判断代理
if ([self.myDelegate respondsToSelector:@selector(GWFMyDelegateBlockNotyView:andString:andImage:)]) { //执行代理
[self.myDelegate GWFMyDelegateBlockNotyView:self andString:myText andImage:image]; dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)( * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{ [SVProgressHUD showWithStatus:@"正在连接..." maskType:SVProgressHUDMaskTypeBlack];
}); dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)( * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{ [SVProgressHUD dismiss];
UIApplication *app = [UIApplication sharedApplication];
NSURL *url = [NSURL URLWithString:@"http://www.dianping.com"];
[app openURL:url]; });
}
} #pragma mark -------block -(void)blockBtnClick {
NSString *myText = @"这是Block传来的值";
UIImage *image = [UIImage imageNamed:@"0 (2)"];
self.myBlock(myText,image); dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)( * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{ [SVProgressHUD showWithStatus:@"正在连接..." maskType:SVProgressHUDMaskTypeBlack];
}); dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)( * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{ [SVProgressHUD dismiss]; UIApplication *app = [UIApplication sharedApplication];
NSURL *url = [NSURL URLWithString:@"http://www.10010.com"];
[app openURL:url]; });
} #pragma mark --------通知 -(void)notyBtnClick {
NSString *myText = @"这是通知传来的值";
UIImage *image = [UIImage imageNamed:@"0 (7)"]; //发布一个通知
[[NSNotificationCenter defaultCenter] postNotificationName:@"myNoty" object:nil userInfo:@{@"myText":myText,@"image":image}]; dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)( * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{ [SVProgressHUD showWithStatus:@"正在连接..." maskType:SVProgressHUDMaskTypeBlack];
}); dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)( * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{ [SVProgressHUD dismiss]; UIApplication *app = [UIApplication sharedApplication];
NSURL *url = [NSURL URLWithString:@"http://www.youku.com"];
[app openURL:url]; });
} @end
控制器中：
// ViewController.m
// 回传值 #import "ViewController.h"
#import "GWFMyDelegateBlockNotyView.h" @interface ViewController ()<GWFMyDelegateBlockNotyViewDelegate> @property (weak, nonatomic) IBOutlet UILabel *myLabel;
@property (weak, nonatomic) IBOutlet UIImageView *myImageView; @end @implementation ViewController - (void)viewDidLoad {
[super viewDidLoad]; self.view.backgroundColor = [UIColor orangeColor];
//添加 myView
GWFMyDelegateBlockNotyView *myView = [[GWFMyDelegateBlockNotyView alloc] init];
myView.frame = CGRectMake(, , , );
[self.view addSubview:myView]; //设置代理
myView.myDelegate = self; //block
myView.myBlock = ^(NSString *block,UIImage *myBlock){
self.myLabel.text = block;
self.myImageView.image = myBlock;
}; //添加通知的一个监听事件
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(noty:) name:@"myNoty" object:nil]; } //实现代理方法
-(void)GWFMyDelegateBlockNotyView:(GWFMyDelegateBlockNotyView *)view andString:(NSString *)string andImage:(UIImage *)image {
self.myLabel.text = string;
self.myImageView.image = image;
} //实现通知的监听方法
-(void)noty:(NSNotification *)noty {
self.myLabel.text = noty.userInfo[@"myText"];
self.myImageView.image = noty.userInfo[@"image"];
} @end
执行结果：
1> 点击代理按钮后：
2> 点击通知按钮后:
3>点击block按钮后:
