iOS反向传值整理

本文主要讲解iOS中常见的反向传值方法。

1.AppDelegate传值

• 在AppDelegate中定义相关的属性变量
• 第二个控制器中为AppDelegate中的属性赋值
• 第一个控制器中在使用的地方取出AppDelegate中的值赋值

//UIApplicationDelegate
@interface AppDelegate : UIResponder <UIApplicationDelegate>
@property (strong, nonatomic) UIWindow *window;
//AppDelegate属性
@property (nonatomic, copy) NSString * string;
@property (nonatomic, strong) UIColor * color;
@end

//第二个控制器
- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{
    //设置数据信息
    AppDelegate * app = [UIApplication sharedApplication].delegate;
    
    app.string = self.field.text;
    app.color = [UIColor orangeColor];
    
    [self.navigationController popViewControllerAnimated:YES];
}

//第一个控制器---设置
 AppDelegate * app = [UIApplication sharedApplication].delegate;
    
    if (app.string) {
        [self.appBtn setTitle:app.string forState:UIControlStateNormal];
        [self.appBtn setBackgroundColor:app.color];
    }

2.代理传值

• 第二个控制器设置代理相关信息
• 第一个控制器实现代理

//第二个控制器
#import <UIKit/UIKit.h>

@protocol ZZYDelegateViewControllerDelegate <NSObject>

@optional

- (void)delegateViewControllerDidClickwithString:(NSString *)string color:(UIColor *)color;

@end

@interface ZZYDelegateViewController : UIViewController

@property (nonatomic, assign) id<ZZYDelegateViewControllerDelegate> delegate;

@end

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{
    if ([self.delegate respondsToSelector:@selector(delegateViewControllerDidClickwithString:color:)]) {
        [self.delegate delegateViewControllerDidClickwithString:self.field.text color:[UIColor greenColor]];
    }
    [self.navigationController popViewControllerAnimated:YES];
}

//第一个控制器

@interface ZZYRootViewController ()<ZZYDelegateViewControllerDelegate>

@property (weak, nonatomic) IBOutlet UIButton *delegateBtn;

@end

- (IBAction)pressDelegateVc:(id)sender {
    ZZYDelegateViewController * vc = [[ZZYDelegateViewController alloc]init];
    vc.delegate = self;
    [self.navigationController pushViewController:vc animated:YES];
}
- (void)delegateViewControllerDidClickwithString:(NSString *)string color:(UIColor *)color
{
    [self.delegateBtn setTitle:string forState:UIControlStateNormal];
    [self.delegateBtn setBackgroundColor:color];
}

3.控制器传值

• 第一个控制器.h里面设置相关属性等信息
• 第二个控制器设置第一个控制器参数,并在对应位置设置相关信息

//第一个控制器
#import <UIKit/UIKit.h>

@interface ZZYRootViewController : UIViewController

@property (weak, nonatomic) IBOutlet UIButton *vcBtn;

@end

//第二个控制器
#import <UIKit/UIKit.h>

@class ZZYRootViewController;

@interface ZZYVCViewController : UIViewController

@property (nonatomic, strong) ZZYRootViewController * rootVc;

@end

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{
    [self.rootVc.vcBtn setTitle:self.field.text forState:UIControlStateNormal];
    [self.rootVc.vcBtn setBackgroundColor:[UIColor orangeColor]];
    [self.navigationController popViewControllerAnimated:YES];
}

4.通知传值

• 第二个控制器发送通知
• 第一个控制器接收通知，设置数据

//第二个控制器
- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{
 
    [[NSNotificationCenter defaultCenter]postNotificationName:@"ZZYNotiSendValue" object:nil userInfo:@{@"value":self.field.text,@"color":[UIColor redColor]}];

    [self.navigationController popViewControllerAnimated:YES];
}

//第一个控制器
  [[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(setNoti:) name:@"ZZYNotiSendValue" object:nil];
- (void)setNoti:(NSNotification *)noti
{
    
    [self.notiBtn setTitle:noti.userInfo[@"value"] forState:UIControlStateNormal];
    [self.notiBtn setBackgroundColor:noti.userInfo[@"color"]];
    
}

5.Block传值

• 第二个控制器设置block相关信息
• 第一个控制器调用block，设置数据

方式一：

//第二个控制器
@interface ZZYBlockViewController : UIViewController

@property (nonatomic, copy) void(^ZZYMyBlock) (NSString * string , UIColor * color);

@end

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{
    if (self.ZZYMyBlock) {
        self.ZZYMyBlock(self.field.text,[UIColor lightGrayColor]);
    }
    [self.navigationController popViewControllerAnimated:YES];
}

//第一个控制器
 ZZYBlockViewController * vc = [[ZZYBlockViewController alloc]init];
   
 [vc setZZYMyBlock:^(NSString * string, UIColor * color) {
        
        [self.blockBtn setTitle:string forState:UIControlStateNormal];
        [self.blockBtn setBackgroundColor:color];
        
    }];

方式二：

//第二个控制器
typedef void(^ZZYMySecBlock) (NSString * string , UIColor * color);

@interface ZZYBlockViewController : UIViewController

@property (nonatomic, copy) ZZYMySecBlock mySecondBlock;

- (void)returnTextBlock:(ZZYMySecBlock)block;

@end

- (void)returnTextBlock:(ZZYMySecBlock)block
{
    self.mySecondBlock = block;
}
- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{
    if (self.mySecondBlock) {
        self.mySecondBlock(self.field.text,[UIColor lightGrayColor]);
    }
    [self.navigationController popViewControllerAnimated:YES];
}

//第一个控制器
 ZZYBlockViewController * vc = [[ZZYBlockViewController alloc]init];

  [vc returnTextBlock:^(NSString *string, UIColor *color) {
        [self.blockBtn setTitle:string forState:UIControlStateNormal];
        [self.blockBtn setBackgroundColor:color];
    }];

3.方式三:

//第二个控制器
#import <UIKit/UIKit.h>

typedef void(^ZZYMyThrBlock) (NSString * string , UIColor * color);

@interface ZZYBlockViewController : UIViewController

@property (nonatomic, copy) ZZYMyThrBlock myThrBlock;

@end

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{

   if (self.myThrBlock) {
       self.myThrBlock(self.field.text,[UIColor lightGrayColor]);
   }
   
   [self.navigationController popViewControllerAnimated:YES];
}

//第一个控制器
ZZYBlockViewController * vc = [[ZZYBlockViewController alloc]init];
   
   vc.myThrBlock = ^(NSString * string, UIColor * color){
       [self.blockBtn setTitle:string forState:UIControlStateNormal];
       [self.blockBtn setBackgroundColor:color];

   };
   [self.navigationController pushViewController:vc animated:YES];

注:上述方式一般首选Block传值，在上述Block的三种方式中，第一种和第三种方式使用的时候需要注意补全block的信息

• 除了上述方式反向传值还可以通过单例、NSUserDefaults方式来进行传值
  示例代码地址