Xcode 5根據使用iOS 7或更低版​​本使用不同的圖像

Question

現在有沒有一種巧妙的方式使用Xcode 5在您的應用中加載不同的圖像，取決於它是否是iOS7？

的最佳解決方案，我可以想出由具有「_7」附加在需要iOS7圖像的端部，然後在該應用中使用的圖像時，我可以去：

NSString *OSSuffix = OSVersion == 7 ? @"_7" : @""; //would be define globally, also pseudo syntax 
[UIImage imageNamed:[NSString stringWithFormat:@"imageName%@", OSSuffix]]; //can make a macro for this probably 

但有一個更好地利用新的資產目錄進行「內置」方式或其他方式？

Answer 1

I was wondering about a similar use case，根據設備類型自動加載568像素高的圖像。由於該功能並沒有提供，我想出了一個補丁UIImage，there’s a sample project here on GitHub：

+ (void) load 
{ 
    if (UI_USER_INTERFACE_IDIOM() != UIUserInterfaceIdiomPhone) { 
     // Running on iPad, nothing to change. 
     return; 
    } 

    CGRect screenBounds = [[UIScreen mainScreen] bounds]; 
    BOOL tallDevice = (screenBounds.size.height > 480); 
    if (!tallDevice) { 
     // Running on a 320✕480 device, nothing to change. 
     return; 
    } 

    method_exchangeImplementations(
     class_getClassMethod(self, @selector(imageNamed:)), 
     class_getClassMethod(self, @selector(imageNamedH568:)) 
    ); 
} 

// Note that calling +imageNamedH568: here is not a recursive call, 
// since we have exchanged the method implementations for +imageNamed: 
// and +imageNamedH568: above. 
+ (UIImage*) imageNamedH568: (NSString*) imageName 
{ 
    NSString *tallImageName = [imageName stringByAppendingString:@"-568h@2x"]; 
    NSString *tallImagePath = [[NSBundle mainBundle] pathForResource:tallImageName ofType:@"png"]; 
    if (tallImagePath != nil) { 
     // Tall image found, let’s use it. We just have to pass the 
     // image name without the @2x suffix to get the correct scale. 
     imageName = [imageName stringByAppendingString:@"-568h"]; 
    } 
    return [UIImage imageNamedH568:imageName]; 
} 

你可以使用同樣的伎倆自動加載基於IOS的一些自定義名稱標籤7的資源。同樣的注意事項適用：UIImage技巧使用方法混合，並可能在生產中有太多的魔法。你的來電。