iOS开发之屏幕旋转

开发了很久一直没有用到过屏幕旋转，一般app设置固定竖屏也就可以了，但是涉及到视频播放的时候全屏播放就是不得不实现的功能了，我们主要介绍两点

一、屏幕旋转监听

-(void)viewDidAppear:(BOOL)animated{
    [super viewDidAppear:animated];
    //开始生成 设备旋转 通知
    [[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];
    
    //添加 设备旋转 通知
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(orientChange:) name:UIDeviceOrientationDidChangeNotification object:nil];
}




-(void)viewDidDisappear:(BOOL)animated{
    [super viewDidDisappear:animated];
    //销毁 设备旋转 通知
    [[NSNotificationCenter defaultCenter] removeObserver:self
                                                    name:UIDeviceOrientationDidChangeNotification
                                                  object:nil
     ];
    
    
    //结束 设备旋转通知
    [[UIDevice currentDevice]endGeneratingDeviceOrientationNotifications];
}

/**屏幕旋转的通知回调*/
- (void)orientChange:(NSNotification *)noti {
    UIDeviceOrientation  orient = [UIDevice currentDevice].orientation;
    switch (orient) {
        case UIDeviceOrientationPortrait:
            NSLog(@"竖直屏幕");
            break;
        case UIDeviceOrientationLandscapeLeft:
            NSLog(@"手机左转");
            break;
        case UIDeviceOrientationPortraitUpsideDown:
            NSLog(@"手机竖直");
            break;
        case UIDeviceOrientationLandscapeRight:
            NSLog(@"手机右转");
            break;
        case UIDeviceOrientationUnknown:
            NSLog(@"未知");
            break;
        case UIDeviceOrientationFaceUp:
            NSLog(@"手机屏幕朝上");
            break;
        case UIDeviceOrientationFaceDown:
            NSLog(@"手机屏幕朝下");
            break;
        default:
            break;
    }
}

备注已经很详细了

UIDeviceOrientationUnknown 未知，屏幕旋转锁定时可能出现
UIDeviceOrientationPortrait 手机垂直，home键在下边
UIDeviceOrientationPortraitUpsideDown手机垂直，home键在上边
UIDeviceOrientationLandscapeLeft 手机水平，home键在右边
UIDeviceOrientationLandscapeRight 手机水平，home键在左边
UIDeviceOrientationFaceUp 手机躺着
UIDeviceOrientationFaceDown 手机趴着

还可以根据statusBar的方向判断

UIInterfaceOrientation orientation = [[UIApplication sharedApplication] statusBarOrientation];
        
        switch (orientation) {
            case UIInterfaceOrientationUnknown:
                NSLog(@"未知");
                break;
            case UIInterfaceOrientationPortrait:
                NSLog(@"竖直");
                break;
            case UIInterfaceOrientationPortraitUpsideDown:
                NSLog(@"屏幕倒立");
                break;
            case UIInterfaceOrientationLandscapeLeft:
                NSLog(@"手机水平，home键在左边");
                break;
            case UIInterfaceOrientationLandscapeRight:
                NSLog(@"手机水平，home键在右边");
                break;
            default:
                break;
        }

二、手动控制屏幕方向

如果我们想在页面中通过按钮设置屏幕方向，那么我们需要先设置支持的方向

设置支持的方向

//设置竖屏
NSNumber *orientationUnknown = [NSNumber numberWithInt:UIInterfaceOrientationUnknown];
        [[UIDevice currentDevice] setValue:orientationUnknown forKey:@"orientation"];
        
        NSNumber *orientationTarget = [NSNumber numberWithInt:UIInterfaceOrientationPortrait];
        [[UIDevice currentDevice] setValue:orientationTarget forKey:@"orientation"];


//设置横屏
NSNumber *orientationUnknown = [NSNumber numberWithInt:UIInterfaceOrientationUnknown];
        [[UIDevice currentDevice] setValue:orientationUnknown forKey:@"orientation"];
        
        NSNumber *orientationTarget = [NSNumber numberWithInt:UIInterfaceOrientationLandscapeRight];
        [[UIDevice currentDevice] setValue:orientationTarget forKey:@"orientation"];

有人可能使用过以下方法，不过应该被禁了，不能上架

//setOrientation 在3.0以后变为私有方法了，不能直接去调用此方法，否则后果就是被打回。
在网上搜了很多很久，都是这种调用私有方法的：
//强制横屏，会被打回。
if ([[UIDevice currentDevice] respondsToSelector:@selector(setOrientation:)]) {
[[UIDevice currentDevice] performSelector:@selector(setOrientation:)
withObject:(id)UIInterfaceOrientationLandscapeRight];
}

三、要实现其他页面都是竖屏，到某一个页面变为横屏

1.创建子类CusNavigationController继承UINavigationController并写入如下方法

//支持旋转
-(BOOL)shouldAutorotate{
    return [self.topViewController shouldAutorotate];
}

//支持的方向
-(UIInterfaceOrientationMask)supportedInterfaceOrientations{
    return [self.topViewController supportedInterfaceOrientations];
}

2.创建子类BaseViewController继承UIViewController并写入如下方法

//支持旋转
-(BOOL)shouldAutorotate{
    return YES;
}

//支持的方向 因为界面A我们只需要支持竖屏
- (UIInterfaceOrientationMask)supportedInterfaceOrientations {
    return UIInterfaceOrientationMaskPortrait;
}

3.控制器继承自BaseViewController并实现以下方法

//支持旋转
-(BOOL)shouldAutorotate{
    return YES;
}

//支持的方向 因为界面A我们只需要支持竖屏
- (UIInterfaceOrientationMask)supportedInterfaceOrientations {
    return UIInterfaceOrientationMaskLandscapeRight|UIInterfaceOrientationMaskPortrait|UIInterfaceOrientationMaskLandscapeLeft;
}

四、如果Masonry涉及到NavigationBar的显示刷新问题可以😂

[self.navigationController.navigationBar.superview layoutSubviews];

⚠️警告同时使用UIDeviceOrientationDidChangeNotification监听屏幕旋转方向并手动设置屏幕物理方向会出现死循环

参考文章
https://my.oschina.net/wolx/blog/387315
https://www.jianshu.com/p/37ea49830d11
https://www.cnblogs.com/niit-soft-518/p/5611298.html
https://blog.csdn.net/goods_boy/article/details/72631424