如何在方向改变时加载人像和风景笔尖？

Question

有没有办法指定笔尖名称，以便应用程序在方向发生变化时自动为风景或肖像拾取相应的笔尖。与iPhone 4和iPhone 5一样，Default @ 2x.png和Default-568h@2x.png类似那是不是？，我正在尝试在App委托方法中使用addObserver进行方向更改，并且工作正常，但是在directionChanged方法中更改笔尖时导致应用崩溃并产生如下错误：

 *** Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[<FRAppDelegate 0xa18bf20> setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key __mapView.'

我的代码如下：

 - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    // Override point for customization after application launch.


    self.viewController = [[FRViewController alloc] initWithNibName:@"FRViewController" bundle:nil];


    [[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];
    [[NSNotificationCenter defaultCenter]
     addObserver:self selector:@selector(orientationChanged:)
     name:UIDeviceOrientationDidChangeNotification
     object:[UIDevice currentDevice]];

    self.window.rootViewController = self.viewController;
    [self.window makeKeyAndVisible];
    return YES;
}

- (void) orientationChanged:(NSNotification *)note
{
    UIDevice * device = note.object;
    switch(device.orientation)
    {
        case UIDeviceOrientationPortrait:
        case UIDeviceOrientationPortraitUpsideDown:
        {
           NSArray *nibArray=[[NSBundle mainBundle] loadNibNamed:@"FRViewController" owner:self options:nil];
           [self.viewController setView:[nibArray objectAtIndex:0]];
            NSLog(@"device orientation comes to portrait mode ");
            /* start special animation */
        }
            break;

        case UIDeviceOrientationLandscapeRight:
        case UIDeviceOrientationLandscapeLeft:
        {
            NSArray *nibArray=[[NSBundle mainBundle] loadNibNamed:@"FRViewControllerLand" owner:self options:nil];
            [self.viewController setView:[nibArray objectAtIndex:0]];
            NSLog(@"device orientatino comes to Landscape mode");
            /* start special animation */
        }
            break;

        default:
            break;
    };
}

Answer 1

1. 如果您确实想加载其他笔尖，则可以使用：

    [[NSBundle mainBundle] loadNibNamed:@"PageView_iPhone" owner:self options:nil]; NSArray* nibViews = [[NSBundle mainBundle] loadNibNamed:@"PageView_iPhone" owner:self options:nil]; PageView_iPhone* myView = [nibViews objectAtIndex:0]; 

然后在某些地方将视图换成新视图

喜欢

self.view = myView;

1. 或者您可以使用Quoted By @Javy

在初始化过程中，我设置了我的视图（以编程方式创建它们），并在视图控制器中为每个视图创建了额外的CGPoint用于中心位置或CGRect用于框架。

在init中创建视图后，我调用名为layoutViewsForOrientation的方法来设置初始位置，并传递当前状态栏的方向。 当方向改变时，我使用以下代码：

 - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation { BOOL result = NO; if ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPhone) { result = (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown); } else { result = YES; } if( result == YES ) [self layoutViewsForOrientation:interfaceOrientation]; return result; } 

Answer 2

尽管这不是加载笔尖的直接解决方案，但我认为您遇到了该错误，因为第二个笔尖没有正确设置UI对象的出口（即__mapView ）。 即，无论您从xib连接__mapView到哪里，该类中都不再存在IBOutlet。

更新：之所以发生这种情况，是因为您正在加载将FRAppDelegate保留为owner的笔尖（您将self指定为owner 。）如果将其更改为self.viewController ，则异常应消失。

即; 代替 ：

NSArray *nibArray=[[NSBundle mainBundle] loadNibNamed:@"FRViewController" owner:self options:nil]; 
NSArray *nibArray=[[NSBundle mainBundle] loadNibNamed:@"FRViewControllerLand" owner:self options:nil];

采用

NSArray *nibArray=[[NSBundle mainBundle] loadNibNamed:@"FRViewController" owner:self.viewController options:nil];
NSArray *nibArray=[[NSBundle mainBundle] loadNibNamed:@"FRViewControllerLand" owner:self.viewController options:nil];