IOS开发 多界面传值

本节学习内容：

1.多界面传值的基本概念

2.多界面传值的方法

3.多界面传值的应用

【多界面传值 属性】

changeColor:改变颜色协义函数

delegate:代理对象设计

assign:代理赋值类型

---

1.创建三视图分别为VCFirst,VCSecond,VCThird，都继承于UIViewController

【VCFIrst.m】

#import"VCFirst.h"

#import"VCSencend.h"

@interface VCFirst()

@end

@implementation VCFirst

-(void)viewDidLoad{

[super viewDidLoad];

}

//点击时推出视图控制器二

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

VCSecond* vc=[[VCSecond alloc]init];

vc.view.backgroundColor=[UIColor orangeColor];

//推出视图控制器二

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

}

---

【VCSecond.h】

//定义代理协义，视图控制器二的协义

@protocol VCSecondDelegate<NSObject>

//定义一个协义函数，改变背景颜色

-(void) changColor:(UIColor*)color;

@end

@interface VCSecond:UIViewController

@property(assign,nonatomic)NSInteger tag;

//定义一个代理对象，代理对象会执行协议函数，通过代理对象实现协义函数，达到代理对象改变本身属性的目的，代理对象一定要实现代理协义

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

@end

【VCSecond.m】

#import"VCSecond.h"

@interface VCSecond()

@end

@implementation VCSecond

-(void)viewDidLoad{

[super viewDidLoad];

self.view.backgroundColor=[UIColor purpleColor];

//必变颜色导般栏按钮

UIBarButtonItem* btnChange=[UIBarButonItem alloc]initWithTitle:@"" style:UIBarButtonItemStyleDone target:self action:@selector(pressChange)];

self.navigationItem.rightBarButtonItem=btnChange;

}

//点击按钮触发代理事件

-(void) pressChange{

//代理对象调用事件函数

_delegate changeColor:[UIColor redColor]];]

}

---

【VCFirst.h】

#import<UIKit/UIKit.h>

#import"VCSecond.h"

//继承 VCSecondDelegate代理

@interface VCFirst:UIViewController<VCSecondDelegate>

-(void)changeColor:(UIColor *)color;

@end

【VCFirst.m】

#import"VCFirst.h"

@inteface VCFirst()

@end

@implementation VCFirst

-(void)viewdidLoad{

[super viewdidLoad];

}

-(void)chanteColor:(UIColor *)color{

self.view.backgroundColor=color;

}

//推出视图控制器二

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

VCSecond* vc=[[VCSecond alloc]init];

//将当前的控制器做为代理对象赋值

vc.delegate=self;

//推出视图控制器二

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

}

---

【Delegate.m】

#import"AppDelegate.h"

#import"VCFirst.h"

#import"VCThird.h"

@interface AppDelegate()

@end

@implementation AppDelegate

-(BOOL)application:(UIApplication *)application didFinshLaunchingWithOptions:(NSDictionary *)launchOptions{

self.window=[[UIwindow alloc]initWithFrame:[UIScreen mainScreen]..bouns]

[self.window makeKeyAndVisible];

VCFirst* vcFirst=[[VCFirst alloc]init];

vcFirst* vcFirst=[[VCFirst alloc]init];

vcFirst.title=@"视图一";

vcFirst.view.backgroundColor=[UIColor whiteColor];

//加载到导航控制器

UINavigationController* nav=[[UINavigationController alloc]initWithRootViewController:vcFirst];

VCThird* vcThird=[[VCThird alloc]init];

VCThird.title=@"视图三";

vcThird.view.backgroundColor=[UIClolor greenColor];

NSArray* array=[NSArray arrayWithObjects:nav,vcThird,nil];

//分栏视图控制器

UITablBarController* tabVC=[[UITabBarController alloc]init];

tabVC.viewControllers=array;

self.window.rootViewController=tabVC;

return YES;

}