Question

stretchableImageWithLeftCapWidth:topCapHeight: is method that used for resize image (iOS lower than 5.0), but in iOS 5 that method is deprecated and iOS 5 have the new one resizableImageWithCapInsets:

What the best way to support resize images in iOS lower than 5 and greeter than 5?
First thing that I know is to use responseToSelector method. But perhaps somebody know an other examples.

Answer 1

It is generally pretty simple to support versions, the only pitfall to avoid is using conditional building to decide what features to support as that would require you to use a specific binary for each version.

I would use something like this:

NSString* featureVersion = @"5.0";
NSString* systemVersion = [[UIDevice currentDevice] systemVersion];
if ([currSysVer compare:reqSysVer options:NSNumericSearch] != NSOrderedAscending)
{
     [object someIOS5SpecificMethod];
}
else
{
     [object alternateMethod];
}

To use version specific classes you could always use something similar to:

Class class = NSClassFromString(@"iOS5OnlyClass");
if (class)
{
   id object = [[class alloc] init];
}