iOS强制splitViewController旋转到横向

Question

我有一个支持横向和纵向模式的分割视图控制器。当详细视图控制器处于特定视图时，我将禁用纵向并仅允许横向方向。但是，如果用户离开该特定视图，将该设备旋转为纵向，然后返回到该特定视图，该纵向仍然是纵向。我需要它自动旋转回风景。以下是我正在使用的。这些方法都是从我的子类UISplitViewController中调用的，以便方向可以取决于视图控制器。

#pragma mark - Orientation 

- (BOOL)shouldAutorotate 
{ 
    // Allow view controller to rotate between landscapes 
    return YES; 
} 

- (NSUInteger)supportedInterfaceOrientations 
{ 
    // Return supported interface orientation 
    return UIInterfaceOrientationMaskLandscape; 
} 

- (UIInterfaceOrientation)preferredInterfaceOrientationForPresentation 
{ 
    // Return preferred orientation 
    return UIInterfaceOrientationLandscapeLeft; 
} 

Answer 1

// This has worked for me - assumes ARC is enabled 

- (void)forceLandscape 
{ 
    UIDevice *myDevice = [UIDevice currentDevice]; 
    if([myDevice respondsToSelector:@selector(setOrientation:)]) 
    { 
     NSInteger param  = UIInterfaceOrientationLandscapeRight; 
     NSMethodSignature *signature = [[myDevice class] instanceMethodSignatureForSelector:@selector(setOrientation:)]; 
     NSInvocation  *invocation = [NSInvocation invocationWithMethodSignature:signature]; 
     [invocation setTarget:myDevice]; 
     [invocation setSelector:@selector(setOrientation:)]; 
     [invocation setArgument:&param 
         atIndex:2]; 
     [invocation invoke]; 
    } 
}