屏幕旋转

本文涉及到的转屏是咱们的app的某个页面设置横竖屏的切换

• 必须先在appdelegate中实现下面的方法

  -(UIInterfaceOrientationMask)application:(UIApplication *)application supportedInterfaceOrientationsForWindow:(UIWindow *)window {
    return UIInterfaceOrientationMaskLandscape | UIInterfaceOrientationMaskPortrait;
   }
  
  

• 在对应的ViewController中重写以下三个方法：

  1. 支持屏幕旋转

       - (BOOL) shouldAutorotate {
     
                retunrn YES;
       }
     

  2.当前viewController支持的设备方向

   -(UIInterfaceOrientationMask)supportedInterfaceOrientations {
    if (self.a == 0) {
  
      return UIInterfaceOrientationMaskPortrait;
  }else {
  
      return UIInterfaceOrientationMaskLandscape;
  } 
  }
  

  其中的a是当前VC的一个全局属性，用于你控制旋转屏幕的时候支持的屏幕方向。

  3. 默认进入到当前的VC的时候显示的方向

-(UIInterfaceOrientation)preferredInterfaceOrientationForPresentation{
   return UIInterfaceOrientationPortrait; 
}  

4. 状态栏是否隐藏

 - (BOOL)prefersStatusBarHidden {
 return NO; // your own visibility code
}

5.点击某个按钮进行横屏

- (void)switchToLandscape
{
 self.a = 1;
 [[UIDevice currentDevice] setValue:[NSNumber numberWithInteger:UIDeviceOrientationLandscapeRight] forKey:@"orientation"];
 [UIViewController attemptRotationToDeviceOrientation];

}

6.点击某个按钮进行竖屏

 - (void)switchToPortrait
{
  self.a = 0;
  [[UIDevice currentDevice] setValue:[NSNumber numberWithInteger:UIDeviceOrientationPortrait] forKey:@"orientation"];
  [UIViewController attemptRotationToDeviceOrientation];
}