iOS 获取屏幕的朝向

  

   

    

     

    
    

     

      //检测屏幕朝向变化
     
    
   

    

     

    
    

     

      -(void)startDeviceOrientationChangeListener {
     
    
   

    

     

    
    

     

          [[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];
     
    
   

    

     

    
    

     

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

    

     

    
    

     

      }
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

      -(void)deviceOrientationDidChange {
     
    
   

    

     

    
    

     
    /*
     
    
   

    

     

    
    

     

       typedef NS_ENUM(NSInteger, UIDeviceOrientation) {
     
    
   

    

     

    
    

     

       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
     
    
   

    

     

    
    

     

       };
     
    
   

    

     

    
    

     

       */
     
    
   

    

     

    
    

     
    UIDeviceOrientation orientation = [UIDevice currentDevice].orientation;
     
    
   

    

     

    
    

     
    NSMutableString *orientationDescription = [[NSMutableString alloc] initWithFormat:@"%ld ", orientation];
     
    
   

    

     

    
    

     
    switch (orientation) {
     
    
   

    

     

    
    

     
        case UIDeviceOrientationUnknown:
     
    
   

    

     

    
    

     

                  [orientationDescription appendFormat:@"%@", @"UIDeviceOrientationUnknown"];
     
    
   

    

     

    
    

     
            break;
     
    
   

    

     

    
    

     
        case UIDeviceOrientationPortrait:
     
    
   

    

     

    
    

     

                  [orientationDescription appendFormat:@"%@", @"UIDeviceOrientationPortrait"];
     
    
   

    

     

    
    

     
            break;
     
    
   

    

     

    
    

     
        case UIDeviceOrientationPortraitUpsideDown:
     
    
   

    

     

    
    

     

                  [orientationDescription appendFormat:@"%@", @"UIDeviceOrientationPortraitUpsideDown"];
     
    
   

    

     

    
    

     
            break;
     
    
   

    

     

    
    

     
        case UIDeviceOrientationLandscapeLeft:
     
    
   

    

     

    
    

     

                  [orientationDescription appendFormat:@"%@", @"UIDeviceOrientationLandscapeLeft"];
     
    
   

    

     

    
    

     
            break;
     
    
   

    

     

    
    

     
        case UIDeviceOrientationLandscapeRight:
     
    
   

    

     

    
    

     

                  [orientationDescription appendFormat:@"%@", @"UIDeviceOrientationLandscapeRight"];
     
    
   

    

     

    
    

     
            break;
     
    
   

    

     

    
    

     
        case UIDeviceOrientationFaceUp:
     
    
   

    

     

    
    

     

                  [orientationDescription appendFormat:@"%@", @"UIDeviceOrientationFaceUp"];
     
    
   

    

     

    
    

     
            break;
     
    
   

    

     

    
    

     
        case UIDeviceOrientationFaceDown:
     
    
   

    

     

    
    

     

                  [orientationDescription appendFormat:@"%@", @"UIDeviceOrientationFaceDown"];
     
    
   

    

     

    
    

     
            break;
     
    
   

    

     

    
    

     

          }
     
    
   

    

     

    
    

     
    NSLog(@"%@", orientationDescription);
     
    
   

    

     

    
    

     

      }
     
    
  
 

我在模拟器上进行测试时发现：第一次会先打印“UIDeviceOrientationUnknown”，接着立马打印“UIDeviceOrientationPortrait”，间隔只有3毫秒左右（当时并没有改变设备方向）

2016-06-21 00:34:31.782 SensorDemo[599:15448] 0 UIDeviceOrientationUnknown
2016-06-21 00:34:31.785 SensorDemo[599:15448] 1 UIDeviceOrientationPortrait

文章来源: blog.csdn.net，作者：福州-司马懿，版权归原作者所有，如需转载，请联系作者。

原文链接：blog.csdn.net/chy555chy/article/details/51724284