控制器之间的数据传递——属性传值

属性传值

我们先在这里约定：界面1传值到界面2为顺传，界面2传值到界面1为逆传

一. 顺传

界面2需要有一个用于接收数据的属性

界面2在压入栈之前，把界面1中的数据直接赋值给界面2的属性

界面2压入栈，实现跳转到界面2

二. 逆传

界面1需要有一个用于接收数据的属性

界面2需要有一个用于保存界面1的属性

界面2在压入栈之前，把界面1控制器赋值给界面2的属性

在界面2中，通过保存的界面1，可以把需要传的值给界面1

界面2出栈，跳转到界面1

三. 具体实现

1. AppDelegate类

#import "AppDelegate.h"
#include "OneViewController.h"

@interface AppDelegate ()

@end

@implementation AppDelegate

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

// 1. 创建窗口
self.window = [[UIWindow alloc] initWithFrame:[UIScreen mainScreen].bounds];

// 2. 创建窗口的根控制器
// 2.1 创建导航控制器的根控制器
UIViewController *oneVc = [[OneViewController alloc] init];
// 2.2 创建导航控制器
UINavigationController *nav = [[UINavigationController alloc] initWithRootViewController:oneVc];
// 2.3 给窗口设置根控制器
self.window.rootViewController = nav;

// 3. 设置窗口为主窗口并显示窗口
[self.window makeKeyAndVisible];

// 隐藏导航控制器的导航条
nav.navigationBarHidden = YES;

return YES;
}

@end

2. OneViewController类

---------- OneViewController.h文件

#import <UIKit/UIKit.h>

@interface OneViewController : UIViewController

// 用于保存数据
@property (nonatomic,strong) NSString *oneStr;

@end

---------- OneViewController.m文件

#import "OneViewController.h"
#import "TwoViewController.h"

@interface OneViewController ()

@property (nonatomic,strong) UITextField *textField;

@end

@implementation OneViewController

- (void)viewDidLoad {
[super viewDidLoad];

//设置控制器View的背景颜色
self.view.backgroundColor = [UIColor greenColor];

// 创建点击按钮
UIButton *clickBtn = [UIButton buttonWithType:UIButtonTypeCustom];
clickBtn.frame = CGRectMake(10, 100, 80, 40);
clickBtn.backgroundColor = [UIColor whiteColor];
[clickBtn setTitle:@"到界面2" forState:UIControlStateNormal];
[clickBtn setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
[clickBtn setTitleColor:[UIColor redColor] forState:UIControlStateHighlighted];
[clickBtn addTarget:self action:@selector(btnClick) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:clickBtn];

// 创建文本框
_textField = [[UITextField alloc] initWithFrame:CGRectMake(10, 150, 250, 40)];
_textField.borderStyle = UITextBorderStyleRoundedRect;
_textField.backgroundColor = [UIColor whiteColor];
[self.view addSubview:_textField];

}

#pragma mark - 点击事件

- (void)btnClick {

// 创建界面2
TwoViewController *twoVc = [[TwoViewController alloc] init];
// 把自己赋值给要跳转控制器的属性，用于数据的逆传
twoVc.oneVC = self;
// 把文本框的值赋值给twoVc控制器
twoVc.twoStr = _textField.text;

// twoVc控制器压入栈，显示该界面2
[self.navigationController pushViewController:twoVc animated:YES];

}

- (void)viewWillAppear:(BOOL)animated {

_textField.text = _oneStr;

}

@end

3. TwoViewController

---------- TwoViewController.h文件

#import <UIKit/UIKit.h>
@class OneViewController;

@interface TwoViewController : UIViewController

// 用于保存数据
@property (nonatomic,strong) NSString *twoStr;

// 保存前一个控制器
@property (nonatomic,strong) OneViewController *oneVC;

@end

---------- TwoViewController.m文件

#import "TwoViewController.h"
#import "OneViewController.h"

@interface TwoViewController ()

@property (nonatomic,strong) UITextField *textField;

@end

@implementation TwoViewController

- (void)viewDidLoad {
[super viewDidLoad];

//设置控制器View的背景颜色
self.view.backgroundColor = [UIColor yellowColor];

// 创建点击按钮
UIButton *clickBtn = [UIButton buttonWithType:UIButtonTypeCustom];
clickBtn.frame = CGRectMake(10, 100, 80, 40);
clickBtn.backgroundColor = [UIColor whiteColor];
[clickBtn setTitle:@"传 值" forState:UIControlStateNormal];
[clickBtn setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
[clickBtn setTitleColor:[UIColor redColor] forState:UIControlStateHighlighted];
[clickBtn addTarget:self action:@selector(btnClick) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:clickBtn];

// 创建文本框
_textField = [[UITextField alloc] initWithFrame:CGRectMake(10, 150, 250, 40)];
_textField.borderStyle = UITextBorderStyleRoundedRect;
_textField.backgroundColor = [UIColor whiteColor];
[self.view addSubview:_textField];
}

#pragma mark - 点击事件

- (void)btnClick {

// 给界面1传递数据
_oneVC.oneStr = _textField.text;

// 跳转界面
[self.navigationController popViewControllerAnimated:YES];

}

- (void)viewWillAppear:(BOOL)animated {

_textField.text = _twoStr;

}

@end