监听iOS检测屏幕旋转状态，不需开启屏幕旋转

-(void)rotation_icon:(float)n {

    UIButton *history_btn= [self.view viewWithTag:<#(NSInteger)#>][self.view viewWithTagName:@"home_history"];
    UIButton *cam_btn = [self.view viewWithTagName:@"cam_btn"];    UIButton *cut_btn = [self.view viewWithTagName:@"cut_btn"];      UIButton *light_btn=[self.view viewWithTagName:@"light_btn"];
    history_btn.transform = CGAffineTransformMakeRotation(n*M_PI/180.0);
    cam_btn.transform = CGAffineTransformMakeRotation(n*M_PI/180.0);
    cut_btn.transform = CGAffineTransformMakeRotation(n*M_PI/180.0);
    light_btn.transform = CGAffineTransformMakeRotation(n*M_PI/180.0);
}
- (void)orientationChanged:(NSNotification *)note  {      UIDeviceOrientation o = [[UIDevice currentDevice] orientation];
    switch (o) {
        case UIDeviceOrientationPortrait:            // Device oriented vertically, home button on the bottom
            [self  rotation_icon:0.0];
            break;
        case UIDeviceOrientationPortraitUpsideDown:  // Device oriented vertically, home button on the top
            [self  rotation_icon:180.0];
            break;
        case UIDeviceOrientationLandscapeLeft:      // Device oriented horizontally, home button on the right
            [[UIApplication sharedApplication] setStatusBarOrientation:UIInterfaceOrientationLandscapeRight animated:YES];

            [self  rotation_icon:90.0*3];
            break;
        case UIDeviceOrientationLandscapeRight:      // Device oriented horizontally, home button on the left
            [[UIApplication sharedApplication] setStatusBarOrientation:UIInterfaceOrientationLandscapeLeft animated:YES];

            [self  rotation_icon:90.0];
            break;
        default:
            break;
    }
 }


-(void)viewWillDisappear:(BOOL)animated {

  NSNotificationCenter *nc = [NSNotificationCenter defaultCenter];
    UIDevice *device = [UIDevice currentDevice]; //Get the device object
    [nc removeObserver:self name:UIDeviceOrientationDidChangeNotification object:device];
}

 - (void)viewDidAppear:(BOOL)animated {
     // Do any additional setup after loading the view from its nib.
 //----- SETUP DEVICE ORIENTATION CHANGE NOTIFICATION -----
    UIDevice *device = [UIDevice currentDevice]; //Get the device object
    [device beginGeneratingDeviceOrientationNotifications]; //Tell it to start monitoring the accelerometer for orientation
    NSNotificationCenter *nc = [NSNotificationCenter defaultCenter]; //Get the notification centre for the app
    [nc addObserver:self selector:@selector(orientationChanged:) name:UIDeviceOrientationDidChangeNotification  object:device];

 

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iPad iPhone  屏幕旋转检测的方法

 

在特别的场景下，需要针对屏幕旋转作特殊处理。在ios系统下实现相关的功能还是比较方便的。

我下面介绍两种方法：

1.注册UIApplicationDidChangeStatusBarOrientationNotification通知（举例:在一个viewcontroller类的viewdidload中注册该通知），示例代码如下：

        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(statusBarOrientationChange:)name:UIApplicationDidChangeStatusBarOrientationNotification object:nil];

 

- (void)statusBarOrientationChange:(NSNotification *)notification

{

    

    UIInterfaceOrientation orientation = [[UIApplication sharedApplication] statusBarOrientation];

    if (orientation == UIInterfaceOrientationLandscapeRight) // home键靠右

    {

        //

    }

    

    if (

        orientation ==UIInterfaceOrientationLandscapeLeft) // home键靠左

    {

        //

    }

    

    if (orientation == UIInterfaceOrientationPortrait)

    {

        //

    }

 

    if (orientation == UIInterfaceOrientationPortraitUpsideDown)

    {

        //

    }

}

注意这种方式监听的是StatusBar也就是状态栏的方向，所以这个是跟你的布局有关的，你的布局转了，才会接到这个通知，而不是设备旋转的通知。

当我们关注的东西和布局相关而不是纯粹设备旋转，我们使用上面的代码作为实现方案比较适合。

2.注册UIDeviceOrientationDidChangeNotification通知（举例:我们同样在一个viewcontroller类的viewdidload中注册该通知），示例代码如下：

 

  [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(orientChange:) name:UIDeviceOrientationDidChangeNotification object:nil];

 

- (void)orientChange:(NSNotification *)noti

{

    

    NSDictionary* ntfDict = [noti userInfo];

    

    UIDeviceOrientation  orient = [UIDevice currentDevice].orientation;

    /*

     UIDeviceOrientationUnknown,

     UIDeviceOrientationPortrait,            // Device oriented vertically, home button on the bottom

     UIDeviceOrientationPortraitUpsideDown,  // Device oriented vertically, home button on the top

     UIDeviceOrientationLandscapeLeft,       // Device oriented horizontally, home button on the right

     UIDeviceOrientationLandscapeRight,      // Device oriented horizontally, home button on the left

     UIDeviceOrientationFaceUp,              // Device oriented flat, face up

     UIDeviceOrientationFaceDown             // Device oriented flat, face down   */

    

           switch (orient)

        {

            case UIDeviceOrientationPortrait:

                

                break;

            case UIDeviceOrientationLandscapeLeft:

    

                

                break;

            case UIDeviceOrientationPortraitUpsideDown:

 

          

                break;

            case UIDeviceOrientationLandscapeRight:

        

           

                break;

                

            default:

                break;

        }

}

注意到这种方式里面的方向还包括朝上或者朝下，很容易看出这个完全是根据设备自身的物理方向得来的，当我们关注的只是物理朝向时，我们通常需要注册该通知来解决问题（另外还有一个加速计的api，可以实现类似的功能，该api较底层，在上面两个方法能够解决问题的情况下建议不要用，使用不当性能损耗非常大）。

 ==================================================

 

最近在ipad上面调试程序的时候 ，虽然  去掉了 屏幕旋转的那俩钩钩，但是在ipadmini 上 还是 会  旋转，很奇怪，ipad系统是 ios12 用 xcode10开发的程序。

 

 

解决方案

 

- (UIInterfaceOrientationMask)application:(UIApplication *)application supportedInterfaceOrientationsForWindow:(nullable UIWindow *)window
{
return UIInterfaceOrientationMaskPortrait;
}
参考链接 https://blog.csdn.net/nadeal/article/details/79542682