iOS 个别界面选择性横屏的解决办法

在 APPDelegate.h 文件中增加属性：是否支持横屏

/***  是否允许横屏的标记 */
@property (nonatomic,assign)BOOL allowRotation;

在 APPDelegate.m 文件中增加方法，控制全部不支持横屏

- (UIInterfaceOrientationMask)application:(UIApplication *)application supportedInterfaceOrientationsForWindow:(UIWindow *)window {
    if (self.allowRotation) {
        return  UIInterfaceOrientationMaskAllButUpsideDown;
    }
    return UIInterfaceOrientationMaskPortrait;
}

这样在其他界面想要横屏的时候，我们只要控制 allowRotation 这个属性就可以控制其他界面进行横屏了。

//需在上面#import "AppDelegate.h"
AppDelegate *appDelegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];
appDelegate.allowRotation = YES;
//不让横屏的时候 appDelegate.allowRotation = NO;即可

需要横屏时，进入界面时

- (void)viewWillAppear:(BOOL)animated {
    [super viewWillAppear:animated];
//如果有导航设置的话 先设置导航
    [self.navigationController setNavigationBarHidden:YES animated:YES];
    [self begainFullScreen];
}

-(void)begainFullScreen
{
    AppDelegate *appDelegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];
    appDelegate.allowRotation = YES;
}

需要横屏时，退出界面时

- (void)viewWillDisappear:(BOOL)animated {
    [super viewWillDisappear:animated];
//如果有导航设置的话 先设置导航
    //[self.navigationController setNavigationBarHidden:NO animated:YES];
    //不让横屏的时候
    [self endFullScreen];
}

// 退出全屏
-(void)endFullScreen
{
    AppDelegate *appDelegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];
    appDelegate.allowRotation = NO;

    //强制归正：
    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 =UIInterfaceOrientationPortrait;
        [invocation setArgument:&val atIndex:2];
        [invocation invoke];
    }
}

界面横屏 所以这里可以使用 通知，就可以解决

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(begainFullScreen) name:UIWindowDidBecomeVisibleNotification object:nil];//进入全屏
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(endFullScreen) name:UIWindowDidBecomeHiddenNotification object:nil];//退出全屏
在退出全屏时，增加逻辑让其强制编程竖屏，这样当退出时就会自动变成竖屏了。
```





```
// 进入全屏
-(void)begainFullScreen
{
    AppDelegate *appDelegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];
    appDelegate.allowRotation = YES;
}
```
```
// 退出全屏
-(void)endFullScreen
{
    AppDelegate *appDelegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];
    appDelegate.allowRotation = NO;

    //强制归正：
    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 =UIInterfaceOrientationPortrait;
        [invocation setArgument:&val atIndex:2];
        [invocation invoke];
    }
}
```
一进入页面就横屏:
```
NSNumber *orientationTarget = [NSNumber numberWithInt:UIInterfaceOrientationLandscapeLeft];
    [[UIDevice currentDevice] setValue:orientationTarget forKey:@"orientation"];
```