ios开发某个页面横不过来屏幕的时候

某一个页面需要横屏，其他的页面任然保持竖屏需要以下关键的几个步骤：

1.修改系统代理方法的返回值

-(UIInterfaceOrientationMask)application:(UIApplication *)application supportedInterfaceOrientationsForWindow:(UIWindow *)window {
    //需要横屏的页面将此属性allowRotation修改为YES，竖屏的页面修改为NO
    if (_allowRotation == YES) {
        //页面仅支持横屏
        return UIInterfaceOrientationMaskLandscapeRight;
    }else{
        //页面仅支持竖屏
        return UIInterfaceOrientationMaskPortrait;
        
    }
}

2.在需要横屏的界面修改方法-(BOOL)shouldAutorotate的返回值为YES

- (BOOL)shouldAutorotate {
    
#if 1
    
    // 设置orientation来横屏竖屏（方式一）
    return YES;
    
#else
    
    // 旋转式横屏竖屏（方式二）
    return NO;
    
#endif
    
}

3.代码实现将屏幕横过来

#pragma mark 横竖屏切换方法
- (void)interfaceOrientation:(UIInterfaceOrientation)orientation
{
    ///  注释掉是因为包含私有API，不敢调用啊
    //    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];
    //    }
    
#if 1
    
    // 设置orientation来横屏竖屏（方式一）
    NSNumber *resetOrientationTarget = [NSNumber numberWithInt:UIInterfaceOrientationUnknown];
    
    [[UIDevice currentDevice] setValue:resetOrientationTarget forKey:@"orientation"];
    
    NSNumber *orientationTarget = [NSNumber numberWithInt:orientation];
    
    [[UIDevice currentDevice] setValue:orientationTarget forKey:@"orientation"];
    //刷新
    [UIViewController attemptRotationToDeviceOrientation];
    
#else
    
    // 旋转式横屏竖屏（方式二）
    if (orientation == UIInterfaceOrientationLandscapeRight) {
        [[UIApplication sharedApplication] setStatusBarOrientation:UIInterfaceOrientationLandscapeRight animated:NO];
        self.view.transform = CGAffineTransformMakeRotation(M_PI/2);
        self.view.frame = CGRectMake(0, 0, MainScreenHeight, MainScreenWidth);
        self.titleImage.frame = CGRectMake(0, 0, MainScreenHeight, MainScreenWidth);
    }
    
    if (orientation == UIInterfaceOrientationPortrait) {
        [[UIApplication sharedApplication] setStatusBarOrientation:UIInterfaceOrientationPortrait animated:NO];
        self.view.transform = CGAffineTransformMakeRotation(0);
        self.view.frame = CGRectMake(0, 0, MainScreenWidth, MainScreenHeight);
        self.titleImage.frame = CGRectMake(0, 0, MainScreenWidth, MainScreenHeight);
    }
    
#endif
}

4.UIViewController系统代理方法来检测屏幕旋转

#pragma mark 横竖屏切换或者进来横屏会触发的方法
-(void)viewWillTransitionToSize:(CGSize)size withTransitionCoordinator:(id<UIViewControllerTransitionCoordinator>)coordinator {
    [coordinator animateAlongsideTransition:^(id<UIViewControllerTransitionCoordinatorContext>  _Nonnull context) {
        //转屏前调入 -- 此处调用在viewDidLoad之前(重写init方法除外)，可在此处做一些控件布局的横竖屏转换
       completion:^(id<UIViewControllerTransitionCoordinatorContext>  _Nonnull context) {
        //转屏后调入 -- 此处调用在viewDidLoad之后，可在此处做一些控件布局的横竖屏转换
    }];
    [super viewWillTransitionToSize:size withTransitionCoordinator:coordinator];
}

经过上述4个步骤可完美实现转屏

by：初光夫