How do I make an app icon for different versions of iOS?

I want iPhone app icon and graphic (not on开发者_开发知识库ly the app icon shows on springboard but also in app inner view) auto meet on OS3 device and OS4 retina device , does it exist a way auto meet but coding ? as I know that we can set the icon configure in setting.plist to define the different app icon on springboard but seem no way to set the inner icon or graphic of the app ....

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Every graphic that you display on a normal-resolution device has an @2x counterpart for a high-resolution device. This applies both to app icons and to the graphics you use within your app.

For example, if you had an image called navbar.png and a hi-res one called navbar@2x.png both in your Xcode project, when you specify it as the image of a UIImageView in Interface Builder or when you specify it in code:

[UIImage imageNamed:@"navbar"];

iOS will automatically pick navbar@2x.png for hi-res devices without you having to write any extra code.

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Create all of your graphic assets at the two sizes, then name the double-sized assets with "@2x" at the end of the name. ie: Icon.png and Icon@2x.png. The iPhone will automatically choose the correct one.