import "AppDelegate.h"

import "ViewController.h"

@interface AppDelegate ()

@end
@implementation AppDelegate

• (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
  // Override point for customization after application launch.
  self.window.backgroundColor = [UIColor whiteColor];
  [self.window makeKeyAndVisible];

  ViewController *viewControiller = [[ViewController alloc]init];
  [self.window setRootViewController:viewControiller];

  return YES;
  }

---

import "ViewController.h"

import "LoginView.h"

@interface ViewController ()

@end

@implementation ViewController

// 是否支持屏幕旋转(默认的是YES)
-(BOOL)shouldAutorotate{
// 如果返回值为YES，支持旋转，返回值为NO，不支持旋转

//  作业：登录界面旋转后重新布局
return YES;

}

// 设置当前界面（viewControler自带的view）所支持的屏幕的方向，系统默认支持竖直，横向向左，横向向右
-(UIInterfaceOrientationMask)supportedInterfaceOrientations{
// 支持所有的屏幕方向
return UIInterfaceOrientationMaskAll;
}

-(void)loadView{
[super loadView];

LoginView *loginView = [[LoginView alloc]init];
self.view = loginView;  

}

import "LoginView.h"

@interface LoginView ()

@property (nonatomic ,retain)UITextField *textField;

@end

@implementation LoginView
-(instancetype)initWithFrame:(CGRect)frame{
self = [super initWithFrame:frame];
if (self) {
[self textField];
}return self;
}
-(UITextField*)textField{
if (!_textField) {

    _textField = [[UITextField alloc]initWithFrame:CGRectMake(80, 100, 100, 40)];

    _textField.backgroundColor = [UIColor redColor];
    [self addSubview:_textField];
}return _textField;

}

// 重写的父类的layoutSubviews，当屏幕旋转的时候，会执行此方法。一般在此方法中对当前view的子视图进行重新布局
-(void)layoutSubviews{
[super layoutSubviews];
// 获取当前屏幕的方向状态
// [UIApplication sharedApplication]：获得当前的应用程序
NSInteger orientation = [UIApplication sharedApplication].statusBarOrientation;
switch (orientation) {

    //  当屏幕方向为水平向左时，我们要将输入框水平居中
    case UIInterfaceOrientationLandscapeLeft:
    {
        CGRect frame = self.textField.frame;
        frame.origin.x = 0;
        self.textField.frame = frame;
    }
        break;
       
        case UIInterfaceOrientationLandscapeRight:
        //  如果是多行执行语句的时候，需要用花括号将他们括起来
    {
        CGRect frame = self.textField.frame;
        frame.origin.x = (CGRectGetWidth(self.frame) - CGRectGetWidth(self.textField.frame))/2;
        self.textField.frame = frame;
    }
        break;
      
    case UIInterfaceOrientationPortrait:{
        CGRect frame = self.textField.frame;
        frame.origin.x = 80;
        self.textField.frame = frame;
    }
        break;
     
    default:
        break;
}

}