维护一套同时兼容 iOS 6 和 iOS 7，并且能够自动适应两个系统的 UI 风格的代码

举例:
ios6:test.png
ios7:ios7_test.png
在ios7Image.plist中添加 "test"

PS:如果要统一成ios7风格，可以看看UI7Kit youknowone/UI7Kit 路 GitHub

@implementation UIImage (HT)

static NSArray *ios7Images;

+ (void)load {

if (IOS7) {

static dispatch_once_t once;

dispatch_once( &once, ^{

ios7Images = [NSArray arrayWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"iOS7Images" ofType:@"plist"]];

[NSObject swizzleClassMethod:self from:@selector(imageNamed:) to:@selector(custom_imageNamed:)];

});

}

}

+ (UIImage *)custom_imageNamed:(NSString *)imageName {

if ([ios7Images containsObject:imageName]) {

return [self custom_imageNamed:[NSString stringWithFormat:@"ios7_%@",imageName]];

}

return [self custom_imageNamed:imageName];

}

@end

OK，图片多的时候怎么办呢?设计师弄好全部以ios7_开头命名的图片,放到一个目录，然后代码

NSArray *searchPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);

NSString *documentPath = [searchPaths objectAtIndex:0];

NSString *path = [documentPath stringByAppendingString:@"/images"];

NSArray *files = [[NSFileManager defaultManager] contentsOfDirectoryAtPath:path error:NULL];

NSMutableArray *array = [NSMutableArray array];

for (NSString *file in files) {

if ([file isEqualToString:@".DS_Store"]) {

continue;

}

NSString *temp = [file stringByReplacingOccurrencesOfString:@"ios7_" withString:@""];

temp = [temp stringByReplacingOccurrencesOfString:@"@2x" withString:@""];

temp = [temp stringByReplacingOccurrencesOfString:@".png" withString:@""];

if ([array containsObject:temp]) {

continue;

}

[array addObject:temp];

}

NSString *plistPath = [documentPath stringByAppendingString:@"/iOS7Images.plist"];

[array writeToFile:plistPath atomically:YES];