#import "ViewController.h"

@interface ViewController ()

@property (weak, nonatomic) IBOutlet UITextField *nameTextField;

@property (weak, nonatomic) IBOutlet UITextField *ageTextField;

@end

@implementation ViewController

- (void)viewDidLoad {

    [super viewDidLoad];

    //1.测试部分：获取沙盒的Library目录

    NSArray *libraryPaths = NSSearchPathForDirectoriesInDomains(NSLibraryDirectory, NSUserDomainMask, YES);

    NSString *libraryPath = [libraryPaths lastObject];

    NSLog(@"libraryPath:%@",libraryPath);

    //2.初始化数据（从第四步保存的数据，读取它，并显示）

    [self initDataByUserDefault];

    //3.在用户将后台程序移除后，需要知道针对这个动作的触发时间/方法（通知）

    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(applicationWillDidEnterBackground:) name:UIApplicationDidEnterBackgroundNotification object:[UIApplication sharedApplication]];

    //4.在后面

}

- (void)initDataByUserDefault{

    //获取全局的NSUserDefaults对象

    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];

    //使用defaults对象来获取保存的数据

    NSString *nameStr = [defaults objectForKey:@"name"];

    NSString *ageStr = [defaults objectForKey:@"age"];

    //将上步获取的数据，赋值给nameTextField

    if (nameStr) {

        self.nameTextField.text = nameStr;

    }

    if (ageStr) {

        self.ageTextField.text = ageStr;

    }

}

- (void)applicationWillDidEnterBackground:(NSNotification *)notitication{

    NSLog(@"测试：进入后台时机");

    //4.在触发方法中去保存你要保存的数据。

    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];

    [defaults setObject:self.nameTextField.text forKey:@"name"];

    [defaults setObject:self.ageTextField.text forKey:@"age"];

    //强制将用户输入的名字和年龄数据保存到硬盘中

    //这里不是自己决定的，由系统决定 ，存在Library目录下。

    [defaults synchronize];

}

@end

- (void)viewDidLoad {

    [super viewDidLoad];

    NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];

    NSString *name = [userDefaults objectForKey:@"user"];

    NSString *pwd = [userDefaults objectForKey:@"pwd"];

    if (name) {

        self.userName.text = name;

    }

    if (pwd) {

        self.passWord.text = pwd;

    }

}

- (IBAction)login:(id)sender {

    NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];

    [userDefaults setObject:self.userName.text forKey:@"user"];

    [userDefaults setObject:self.passWord.text forKey:@"pwd"];
　　 [userDefaults synchronize];

    BViewController *BVC = [[BViewController alloc] init];

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

}