如何在方向改變時加載人像和風景筆尖？

Question

有沒有辦法指定筆尖名稱，以便應用程序在方向發生變化時自動為風景或肖像拾取相應的筆尖。與iPhone 4和iPhone 5一樣，Default @ 2x.png和Default-568h@2x.png類似那是不是？，我正在嘗試在App委托方法中使用addObserver進行方向更改，並且工作正常，但是在directionChanged方法中更改筆尖時導致應用崩潰並產生如下錯誤：

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

我的代碼如下：

 - (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. 如果您確實想加載其他筆尖，則可以使用：

    [[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]; 

然后在某些地方將視圖換成新視圖

喜歡

self.view = myView;

1. 或者您可以使用Quoted By @Javy

在初始化過程中，我設置了我的視圖（以編程方式創建它們），並在視圖控制器中為每個視圖創建了額外的CGPoint用於中心位置或CGRect用於框架。

在init中創建視圖后，我調用名為layoutViewsForOrientation的方法來設置初始位置，並傳遞當前狀態欄的方向。 當方向改變時，我使用以下代碼：

 - (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

盡管這不是加載筆尖的直接解決方案，但我認為您遇到了該錯誤，因為第二個筆尖沒有正確設置UI對象的出口（即__mapView ）。 即，無論您從xib連接__mapView到哪里，該類中都不再存在IBOutlet。

更新：之所以發生這種情況，是因為您正在加載將FRAppDelegate保留為owner的筆尖（您將self指定為owner 。）如果將其更改為self.viewController ，則異常應消失。

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];