iOS 屏幕旋转 手动和自动

iOS屏幕旋转

首先iPhone中屏幕分为状态栏方向和设备方向

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
};

typedef NS_ENUM(NSInteger, UIInterfaceOrientation) {
UIInterfaceOrientationUnknown            = UIDeviceOrientationUnknown,
UIInterfaceOrientationPortrait           = UIDeviceOrientationPortrait,
UIInterfaceOrientationPortraitUpsideDown = UIDeviceOrientationPortraitUpsideDown,
UIInterfaceOrientationLandscapeLeft      = UIDeviceOrientationLandscapeRight,
UIInterfaceOrientationLandscapeRight     = UIDeviceOrientationLandscapeLeft
};

系统提供两个地方来设置设备的方向，取两个地方的交集是最后的设备所支持的方向

-(NSUInteger)application:(UIApplication *)application supportedInterfaceOrientationsForWindow:(UIWindow *)window;
-(NSUInteger)supportedInterfaceOrientations;

这里需要注意的是返回的时下面的枚举

typedef NS_OPTIONS(NSUInteger, UIInterfaceOrientationMask) {
UIInterfaceOrientationMaskPortrait = (1 << UIInterfaceOrientationPortrait),
UIInterfaceOrientationMaskLandscapeLeft = (1 << UIInterfaceOrientationLandscapeLeft),
UIInterfaceOrientationMaskLandscapeRight = (1 << UIInterfaceOrientationLandscapeRight),
UIInterfaceOrientationMaskPortraitUpsideDown = (1 << UIInterfaceOrientationPortraitUpsideDown),
UIInterfaceOrientationMaskLandscape = (UIInterfaceOrientationMaskLandscapeLeft | UIInterfaceOrientationMaskLandscapeRight),
UIInterfaceOrientationMaskAll = (UIInterfaceOrientationMaskPortrait | UIInterfaceOrientationMaskLandscapeLeft | UIInterfaceOrientationMaskLandscapeRight | UIInterfaceOrientationMaskPortraitUpsideDown),
UIInterfaceOrientationMaskAllButUpsideDown = (UIInterfaceOrientationMaskPortrait | UIInterfaceOrientationMaskLandscapeLeft | UIInterfaceOrientationMaskLandscapeRight),
};

在转动屏幕的时候会触发下面方法

-(BOOL)shouldAutorotate；

在该方法返回真,自动调用上面的两个方法得到方向。

修改状态栏方向的方法

1、使用私有API setOrientation;

2、修改状态栏的方向，并通过设置View的transform来达到伪旋转的结果，但是设备方向并没有改变

3、主动出发系统支持的方法，就相当于让这个vc在重新出来的时候系统判断所支持的方向的机制重新走一遍。

- (void)awakeSupportInterOrtation:(UIViewController *)showVC completion:(void(^)(void))block
{
UIViewController *vc = [[UIViewController alloc] init];
void(^completion)() = ^() {
[showVC dismissViewControllerAnimated:NO completion:^{
if (block)
{
block();
}
}];
};

// This check is needed if you need to support iOS version older than 7.0
BOOL canUseTransitionCoordinator = [showVC respondsToSelector:@selector(transitionCoordinator)];

if (canUseTransitionCoordinator)
{
[showVC presentViewController:vc animated:NO completion:nil];
[showVC.transitionCoordinator animateAlongsideTransition:nil completion:^(id<UIViewControllerTransitionCoordinatorContext> context) {
completion();
}];
}
else
{
[showVC presentViewController:vc animated:NO completion:completion];
}
}

-(NSUInteger)supportedInterfaceOrientations
{
return UIInterfaceOrientationMaskPortrait;
}

-(BOOL)shouldAutorotate
{
return YES;
}

在需要转为竖屏的时候调用一个方法，在后面两个方法中如上实现，第二个方法中返回的是你最终要转向的方向。