iOS屏幕旋转

方式一

假旋转

• 修改view的transform，通过旋转来实现横屏

工程配置

1530621362531.jpg

重写shouldAutorotate

/*当前需要转屏幕的控制器重写*/
- (BOOL)shouldAutorotate {
    return NO;
}

• 需要注意的是 shouldAutorotate通常会被拦截，比如项目中rootViewCntroller通常为UITabBarController 和 UINavgationController

• 这时候就需要重写UITabBarController和UINavgationController的shouldAutorotate，找到当前展示/需要转屏幕的控制器（VC），以解决shouldAutorotate被拦截。

• 采用分类的形式，对于已经成型的项目来说，采用这种方式,下面代码摘取子ZFPlayer

@implementation UITabBarController (ZFPlayerRotation)

+ (void)load {
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        SEL selectors[] = {
            @selector(selectedIndex)
        };
        
        for (NSUInteger index = 0; index < sizeof(selectors) / sizeof(SEL); ++index) {
            SEL originalSelector = selectors[index];
            SEL swizzledSelector = NSSelectorFromString([@"zf_" stringByAppendingString:NSStringFromSelector(originalSelector)]);
            Method originalMethod = class_getInstanceMethod(self, originalSelector);
            Method swizzledMethod = class_getInstanceMethod(self, swizzledSelector);
            if (class_addMethod(self, originalSelector, method_getImplementation(swizzledMethod), method_getTypeEncoding(swizzledMethod))) {
                class_replaceMethod(self, swizzledSelector, method_getImplementation(originalMethod), method_getTypeEncoding(originalMethod));
            } else {
                method_exchangeImplementations(originalMethod, swizzledMethod);
            }
        }
    });
}

- (NSInteger)zf_selectedIndex {
    NSInteger index = [self zf_selectedIndex];
    if (index > self.viewControllers.count) { return 0; }
    return index;
}

/**
 * If the root view of the window is a UINavigationController, you call this Category first, and then UIViewController called.
 * All you need to do is revisit the following three methods on a page that supports directions other than portrait.
 */

// Whether automatic screen rotation is supported.
- (BOOL)shouldAutorotate {
    UIViewController *vc = self.viewControllers[self.selectedIndex];
    if ([vc isKindOfClass:[UINavigationController class]]) {
        UINavigationController *nav = (UINavigationController *)vc;
        return [nav.topViewController shouldAutorotate];
    } else {
        return [vc shouldAutorotate];
    }
}

// Which screen directions are supported.
- (UIInterfaceOrientationMask)supportedInterfaceOrientations {
    UIViewController *vc = self.viewControllers[self.selectedIndex];
    if ([vc isKindOfClass:[UINavigationController class]]) {
        UINavigationController *nav = (UINavigationController *)vc;
        return [nav.topViewController supportedInterfaceOrientations];
    } else {
        return [vc supportedInterfaceOrientations];
    }
}

// The default screen direction (the current ViewController must be represented by a modal UIViewController (which is not valid with modal navigation) to call this method).
- (UIInterfaceOrientation)preferredInterfaceOrientationForPresentation {
    UIViewController *vc = self.viewControllers[self.selectedIndex];
    if ([vc isKindOfClass:[UINavigationController class]]) {
        UINavigationController *nav = (UINavigationController *)vc;
        return [nav.topViewController preferredInterfaceOrientationForPresentation];
    } else {
        return [vc preferredInterfaceOrientationForPresentation];
    }
}

@implementation UINavigationController (ZFPlayerRotation)

/**
 * If the root view of the window is a UINavigationController, you call this Category first, and then UIViewController called.
 * All you need to do is revisit the following three methods on a page that supports directions other than portrait.
 */

// Whether automatic screen rotation is supported
- (BOOL)shouldAutorotate {
    NSLog(@"shouldAutorotate  %@",@([self.topViewController shouldAutorotate]));
    return [self.topViewController shouldAutorotate];
}

// Which screen directions are supported
- (UIInterfaceOrientationMask)supportedInterfaceOrientations {
    NSLog(@"supportedInterfaceOrientations  %@",@([self.topViewController supportedInterfaceOrientations]));

    return [self.topViewController supportedInterfaceOrientations];
}

// The default screen direction (the current ViewController must be represented by a modal UIViewController (which is not valid with modal navigation) to call this method).
- (UIInterfaceOrientation)preferredInterfaceOrientationForPresentation {
    NSLog(@"preferredInterfaceOrientationForPresentation  %@",@([self.topViewController preferredInterfaceOrientationForPresentation]));

    return [self.topViewController preferredInterfaceOrientationForPresentation];
}

- (UIViewController *)childViewControllerForStatusBarStyle {
    NSLog(@"childViewControllerForStatusBarStyle  %@",self.topViewController);

    return self.topViewController;
}

- (UIViewController *)childViewControllerForStatusBarHidden {
    NSLog(@"childViewControllerForStatusBarHidden  %@",self.topViewController);

    return self.topViewController;
}

@end

• 原理就是一定要找到当前展示的ViewController，然后 shouldAutorotate == NO

遇到过的坑 （一定要追到shouldAutorotate）

• UITabBarController 被包装到了一个UIViewController，成为了这个UIViewController的子控制器，并且 UIViewController == rootViewController

• 这种结构首先 shouldAutorotate 被UIViewController拦截无法往下传递，所以这时转屏幕无论修改状态栏到什么方向都是不起作用的

• 必须重写UIViewController 的 shouldAutorotate，然后找到TabBarController->NavgationController->UIViewController
  直到找到当前需要转屏的UIViewController，不管控制器结构有多深，都需要一层一层的传递下去

重写supportedInterfaceOrientations

- (UIInterfaceOrientationMask)supportedInterfaceOrientations {
    return UIInterfaceOrientationMaskAllButUpsideDown;
}

• 这些都完成以后就可以监听屏幕旋转做相应的处理了

- (void)addDeviceOrientationObserver {
    if (![UIDevice currentDevice].generatesDeviceOrientationNotifications) {
        [[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];
    }
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(handleDeviceOrientationChange) name:UIDeviceOrientationDidChangeNotification object:nil];
}

方式二

强制横屏

• 相对来说方式一体验要好很多，旋转的动画可以自定义

- (void)interfaceOrientation:(UIInterfaceOrientation)orientation
{
  if ([[UIDevice currentDevice] respondsToSelector:@selector(setOrientation:)]) {
    SEL selector = NSSelectorFromString(@"setOrientation:");
    NSInvocation *invocation = [NSInvocation invocationWithMethodSignature:[UIDevice instanceMethodSignatureForSelector:selector]];
    [invocation setSelector:selector];
    [invocation setTarget:[UIDevice currentDevice]];
    int val = orientation;
    // 从2开始是因为0 1 两个参数已经被selector和target占用
    [invocation setArgument:&val atIndex:2];
    [invocation invoke];
  }
}

假旋转传送门