UIDevice类提供了一个单例实例代表当前的设备。从这个实例中可以获得的信息设备，比如操作系统名称、电池电量值(batteryLevel)、电池状态(batteryState)、设备的类型(model，比如iPod、iPhone等)、设备的系统(systemVersion)
屏幕的旋转朝向可以通过  [[UIDevice currentDevice]orientation] 判断，orientation是个Integer类型，每个值表示相应的朝向，必须在调用beginGeneratingDeviceOrientationNotifications方法后，此orientation属性才有效，否则一直是0。

//
//  ViewController.m
//
 
#import "ViewController.h"
 
@interface ViewController ()
/**
 *  UIImageView
 */
@property(nonatomic,strong)UIImageView *imageView;
 
 
@end
 
 
@implementation ViewController
 
 
- (void)handleDeviceOrientationDidChange:(UIInterfaceOrientation)interfaceOrientation
{
    //1.获取 当前设备 实例
    UIDevice *device = [UIDevice currentDevice] ;
     
     
     
     
    /**
     *  2.取得当前Device的方向，Device的方向类型为Integer
     *
     *  必须调用beginGeneratingDeviceOrientationNotifications方法后，此orientation属性才有效，否则一直是0。orientation用于判断设备的朝向，与应用UI方向无关
     *
     *  @param device.orientation
     *
     */
 
    switch (device.orientation) {
        case UIDeviceOrientationFaceUp:
            NSLog(@"屏幕朝上平躺");
            break;
             
        case UIDeviceOrientationFaceDown:
            NSLog(@"屏幕朝下平躺");
            break;
             
            //系統無法判斷目前Device的方向，有可能是斜置
        case UIDeviceOrientationUnknown:
            NSLog(@"未知方向");
            break;
             
        case UIDeviceOrientationLandscapeLeft:
            NSLog(@"屏幕向左横置");
            break;
             
        case UIDeviceOrientationLandscapeRight:
            NSLog(@"屏幕向右橫置");
            break;
             
        case UIDeviceOrientationPortrait:
            NSLog(@"屏幕直立");
            break;
             
        case UIDeviceOrientationPortraitUpsideDown:
            NSLog(@"屏幕直立，上下顛倒");
            break;
             
        default:
            NSLog(@"无法辨识");
            break;
    }
 
}
 
 
- (void)viewDidLoad {
 
     
    //设备名称  e.g. "My iPhone"
    NSString *strName = [[UIDevice currentDevice] name];
    NSLog(@"设备名称：%@", strName);
 
     
     
    /**
     * 系统名称 e.g. @"iOS"
     */
    NSString *strSysName = [[UIDevice currentDevice] systemName];
    NSLog(@"系统名称：%@", strSysName);
     
     
 
    /**
     * 系统版本号 e.g. @"4.0"
     */
    NSString *strSysVersion = [[UIDevice currentDevice] systemVersion];
    NSLog(@"系统版本号：%@", strSysVersion);
     
     
     
     
    /**
     * 设备类型 e.g. @"iPhone", @"iPod touch"
     */
    NSString *strModel = [[UIDevice currentDevice] model];
    NSLog(@"设备类型：%@", strModel);
     
     
     
    /**
     * 本地设备模式 localized version of model
     */
    NSString *strLocModel = [[UIDevice currentDevice] localizedModel];
    NSLog(@"本地设备模式：%@", strLocModel);
     
 
     
     
    /**
     * UUID 　可用于唯一地标识该设备
     */
    NSUUID *identifierForVendor = [[UIDevice currentDevice] identifierForVendor];
    NSLog(@"UUID：%@", identifierForVendor.UUIDString);
     
     
     
    /**
     * UIImage 对象
     */
    UIImage *image = [UIImage imageNamed:@"scroll.jpg"];
    self.imageView.image = image;
     
    // 设置图片范围
    CGFloat imageH = image.size.height;
    CGFloat imageW = image.size.width;
    CGFloat imageX = 0;
    CGFloat imageY = 0;
    self.imageView.frame = CGRectMake(imageX, imageY, imageW, imageH);
    [self.view addSubview:self.imageView];
     
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
}
 
 
-(void)viewDidAppear:(BOOL)animated
{
     
    /**
     *  开始生成 设备旋转 通知
     */
    [[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];
     
     
    /**
     *  添加 设备旋转 通知
     *
     *  @param handleDeviceOrientationDidChange: handleDeviceOrientationDidChange: description
     *
     *  @return return value description
     */
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(handleDeviceOrientationDidChange:)
                                                 name:UIDeviceOrientationDidChangeNotification
                                               object:nil
     ];
     
 
 
}
 
 
 
-(void)viewDidDisappear:(BOOL)animated
{
     
     
     
    /**
     *  销毁 设备旋转 通知
     *
     *  @return return value description
     */
    [[NSNotificationCenter defaultCenter] removeObserver:self
                                                    name:UIDeviceOrientationDidChangeNotification
                                                  object:nil
     ];
     
     
    /**
     *  结束 设备旋转通知
     *
     *  @return return value description
     */
    [[UIDevice currentDevice]endGeneratingDeviceOrientationNotifications];
     
}
 
 
 
- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}
 
 
 
 
#pragma 懒加载
 
- (UIImageView *)imageView
{
    if (!_imageView) {
        _imageView = [[UIImageView alloc] init];
    }
    return _imageView;
}
 
@end