这是我发现的最好的帖子,但在Xcode 7中它没有显示“Retina 4 2x”或iPhone 6/6

Xcode 6 – xcassets for universal image support

在xcode 7中有一个通用选项,但这三个图像不支持所有设备大小.

我已经看过你可以在资产目录之外提供自己的图像的选项,但我真的很想使用资产目录.

How to use xcassets/universal background images for different iPhones/iPads?

编辑：
看起来我可能不得不去无资产目录路线:(

一个)

我希望将来证明这个解决方案,所以它会回落,如果需要,请调整最合适的图像,因为我不确定会发生什么.

NSNumber *screenWidth = @([UIScreen mainScreen].bounds.size.width);
NSString *imageName = [NSString stringWithFormat:@"name-%@w",screenWidth];
UIImage *image = [UIImage imageNamed:imageName];

B)

或者这个代码可能更好？虽然我不确定它与哪种尺寸有关,但由于它不支持x3图像,它也有点过时了？

#import <UIKit/UIKit.h>

@interface UIImage (DefaultImage)

// uses statusbar orientation
+ (UIImage *)defaultImage;

//uses given orientation
+ (UIImage *)defaultImageForOrientation:(UIInterfaceOrientation)orient;

@end

@implementation UIImage (DefaultImage)

+ (UIImage *)defaultImage {
    return [self defaultImageForOrientation:[[UIApplication sharedApplication] statusBarOrientation]];
}

+ (UIImage  *)defaultImageForOrientation:(UIInterfaceOrientation)orient {
    // choose the correct launch image for orientation,device and scale
    NSMutableString *launchImageName = [[NSMutableString alloc] initWithString:@"Default"];
    BOOL isPad = ( UI_USER_INTERFACE_IdioM() == UIUserInterfaceIdiomPad );
    if ( isPad ) {
        BOOL isLandscape = UIInterfaceOrientationIsLandscape(orient);
        NSString *imageOrientation = (isLandscape) ? @"Landscape" : @"Portrait";

        BOOL isRetina = ([[UIScreen mainScreen] respondsToSelector:@selector(scale)] && [[UIScreen mainScreen] scale] == 2.0);
        NSString *scaleString = (isRetina) ? @"@2x" : @"";

        // Default-Landscape~ipad.png
        // Default-Landscape@2x~ipad.png
        // Default-Portrait~ipad.png
        // Default-Portrait@2x~ipad.png
        launchImageName = [NSMutableString stringWithFormat:@"%@-%@%@.png",launchImageName,imageOrientation,scaleString];       
    } else {
        if ( CGRectGetHeight([UIScreen mainScreen].bounds) > 480.f) {
            // Default-568h.png
            launchImageName = [NSMutableString stringWithFormat:@"%@-568h.png",launchImageName];
        } else {
            // Default.png
            // Default@2x.png
            launchImageName = [NSMutableString stringWithFormat:@"%@.png",launchImageName];
        }
    }
    return [UIImage imageNamed:launchImageName];
}

@end

免责声明：摘自https://github.com/Daij-Djan/DDUtils

C)

这看起来也很不错,但它正在重新调整大小并且不使用实际的清晰图像,并且没有后退.

https://gist.github.com/kevindelord/fe2e691d06ab745fbb00

NSString *extension = @"";      // iPhone 3GS and earlier
if (scale == 3.f) {
    extension = @"@3x";         // iPhone 6 Plus
} else if (scale == 2.f && h == 568.0f && w == 320.0f) {
    extension = @"-568h@2x";    // iPhone 5,5S,5C
} else if (scale == 2.f && h == 667.0f && w == 375.0f) {
    extension = @"-667h@2x";    // iPhone 6
} else if (scale == 2.f && h == 480.0f && w == 320.0f) {
    extension = @"@2x";         // iPhone 4,4S
} else if (scale == 1.f && h == 1024.0f && w == 768.0f) {
    extension = @"-512h";       // iPad Mini,iPad 2,iPad 1
} else if (scale == 2.f && h == 1024.0f && w == 768.0f) {
    extension = @"-1024h@2x";   // iPad Mini 3,iPad Mini 2,iPad Air,iPad Air 2
}
return extension;