iOS-传值大全

来源：互联网发布：三菱plc编程实例3000 编辑：程序博客网时间：2024/06/05 21:54

前言

iOS传值方式很多，这里面我主要讲几种常用的传值；

以下传值正向传值A页面到B页面，反向传值B页面传到A页面。

1.属性传值

A页面：

SecondViewController *svc = [[SecondViewController alloc]init];  UINavigationController *nvc = [[UINavigationController alloc]initWithRootViewController:svc];  svc.passValue = @"这是传的值";  [self presentViewController:nvc animated:YES completion:nil];

B页面：

先声明一个属性：

@property (nonatomic,copy) NSString *passValue;

使用传的值

NSLog(@"%@",_passValue);

2.文件传值

A页面：

NSUserDefaults *ud = [NSUserDefaults standardUserDefaults];  [ud setObject:@"这是传的值" forKey:@"passValue"];  [ud synchronize];

B页面：

NSUserDefaults *ud = [NSUserDefaults standardUserDefaults];  NSString *str = [ud objectForKey:@"passValue"];  NSLog(@"str == %@",str);

3.代理传值

B页面设置代理

@protocol ChangeValueDelegate <NSObject>    - (void)changeValueWithPassValue:(NSString *)passValue;    @end    @interface DetailViewController : UIViewController    @property (assign, nonatomic) id<ChangeValueDelegate> delegate;    @end

赋值

if ([self.delegate respondsToSelector:@selector(changeValueWithPassValue:)]) {              [self.delegate changeValueWithPassValue:@"这是传的值"];  }

A页面遵循代理

@interface RootViewController ()<ChangeValueDelegate>

SecondViewController *dvc = [[SecondViewController alloc] init];  dvc.delegate = self;  [self.navigationController pushViewController:dvc animated:YES];

现实代理

- (void)changeValueWithPassValue:(NSString *)titleStr{      NSLog(@"titleStr == %@",titleStr);  }

4.广播传值

A页面发送通知

NSDictionary *dict = [NSDictionary dictionaryWithObject:@"我是传的值" forKey:@"value"];  [[NSNotificationCenter defaultCenter] postNotificationName:@"KPassVaule" object:nil userInfo:dict];

B页面接收通知

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(getPassVauleget:) name:@"KPassVaule" object:nil];

- (void)getPassVauleget:(NSNotification *)notifi{      NSString *str = [notifi.userInfo objectForKey:@"value"];      NSLog(@"str == %@",str);  }

5.KVO传值

在初始化方法中加入

[_stu addObserver:self forKeyPath:@"name" options:NSKeyValueObservingOptionNew | NSKeyValueObservingOptionOld context:nil];

在dealloc中移除KVO监听：

[_stu removeObserver:self forKeyPath:@"name" context:nil];

- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(voidvoid *)context{      if ([object isKindOfClass:[Student class]]) {          NSLog(@"_stu-old:%@",[change objectForKey:@"old"]);          NSLog(@"_stu-new:%@",[change objectForKey:@"new"]);      }  }

6.blcok反向传值

A页面

DetailViewController *dvc = [[DetailViewController alloc] init];  dvc.fontSize = _label.font.pointSize;  void (^mBlocks)(float value);  mBlocks = ^(float value){       _label.font = [UIFont systemFontOfSize:value];  };  [dvc changeFont:mBlocks];  [self presentViewController:dvc animated:YES completion:^{     NSLog(@"hb");  }];

B页面

#import <UIKit/UIKit.h>    @interface DetailViewController : UIViewController{      void (^_mBlock)(float value);  }    @property (assign, nonatomic) float fontSize;    - (void)changeFont:(void (^)(float value))mBlock;    @end

传值

_mBlock(1111.00);

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