ios - 使用NSNotificationCenter和UIDeviceOrientation更改方向

Question

当我在xCode中更改模拟器的方向时，为什么不起作用？我看到所有时间都等于ViewController上的标签，并且没有出现NSLog。

ViewController.m:

- (void)viewDidLoad
{
    [self orientacionActual];
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(orientacionActual)
                                                 name:UIDeviceOrientationDidChangeNotification
                                               object:nil];

}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

-(UIDeviceOrientation) orientacionActual
{
    UIDeviceOrientation orientacionActual = [UIDevice currentDevice].orientation;
    return orientacionActual;
}

- (void) cambiaOrientacion:(NSNotification *) notificación
{
    if(UIDeviceOrientationIsLandscape([self orientacionActual]))
    {
        self.LabelEstoy.text = @"Landscape";
        NSLog(@"Landscape");
    } else if (UIDeviceOrientationIsPortrait([self orientacionActual]))
    {
        self.LabelEstoy.text = @"Portrait";
        NSLog(@"Portrait");
    }
}

Answer 1

调用UIApplicationDidChangeStatusBarOrientationNotification而不是更改设备方向。另外，我不确定您的目标是什么，但请尝试使用以下代码段:

内部viewDidLoad:

    [[NSNotificationCenter defaultCenter] addObserver:self 
                      selector:@selector(cambiaOrientacion:)
                          name:UIApplicationDidChangeStatusBarOrientationNotification
                        object:nil];

及以下:

- (void)cambiaOrientacion:(NSNotification *)notificacion
{
    UIInterfaceOrientation orientation = [[[notification userInfo] 
       objectForKey:UIApplicationStatusBarOrientationUserInfoKey] integerValue];
    if (UIInterfaceOrientationIsLandscape(orientation))
    {
        self.LabelEstoy.text = @"Landscape";
        NSLog(@"Landscape");
    } else
    {
        self.LabelEstoy.text = @"Portrait";
        NSLog(@"Portrait");
    }
}

和 orientacionActual方法在您的代码中多余，没有任何意义。

不要忘记在 [[NSNotificationCenter defaultCenter] removeObserver:self]中添加 dealloc。