2019-4-10

效果：

屏幕旋转.gif

一、targets选择

image.png

二、根控制器（UINavigationController 或 UITabBarController）重写

- (BOOL)shouldAutorotate {
    return YES;
}

- (UIInterfaceOrientationMask)supportedInterfaceOrientations {
    //判断当前顶层显示的是 你要设置横屏的那个控制器（FireAnimationViewController）
    if([self.selectedViewController isKindOfClass:[UINavigationController class]] && [[(UINavigationController *)[self selectedViewController] topViewController] isKindOfClass:[FireAnimationViewController class]]){
        return UIInterfaceOrientationMaskLandscape;
    }
    else{
        return UIInterfaceOrientationMaskPortrait;
    }
}

- (UIInterfaceOrientation)preferredInterfaceOrientationForPresentation {
    return UIInterfaceOrientationPortrait;
}

三、在要设置横屏的VC里设置

- (void)viewDidAppear:(BOOL)animated{
    [super viewDidAppear:animated];
     //首先设置UIInterfaceOrientationUnknown欺骗系统，避免可能出现  直接设置无效的情况
    [[UIDevice currentDevice] setValue:[NSNumber numberWithInt:UIInterfaceOrientationUnknown] forKey:@"orientation"];
    [[UIDevice currentDevice] setValue:[NSNumber numberWithInt:UIInterfaceOrientationLandscapeRight] forKey:@"orientation"];
}
-(void)viewDidDisappear:(BOOL)animated{
    [super viewDidDisappear:animated];
    //首先设置UIInterfaceOrientationUnknown欺骗系统，避免可能出现直接设置无效的情况
    [[UIDevice currentDevice] setValue:[NSNumber numberWithInt:UIInterfaceOrientationUnknown] forKey:@"orientation"];
    [[UIDevice currentDevice] setValue:[NSNumber numberWithInt:UIInterfaceOrientationPortrait] forKey:@"orientation"];

}

重写view的出现和消失方法 改变设备的方向，主要触发根控制器的supportedInterfaceOrientations方法 使屏幕旋转，如果不设置，会发现push进来时VC没旋转，手动旋转屏幕VC才会改变方向，view消失时同理，不设置则会pop出来的时候，vc和上个页面一样是横屏的，手动旋转屏幕才会变成竖屏的