Best way to set the size of UIViews size in iPhone application (so everything looks good on both Retina and older display)

I have the following problem. My application has a tab bar at the bottom and a simple TextView above. In order to fit well TextView above tab bar I had to resize it (I did it through Interface Builder) - I just set height to 401px (usually I hate to do such things).

Then I have tested application on the simulator, to my surprise everything looked o.k. on both standard iPhone display and Retina display. Since I do not have an iPhone I am wondering if everything would look good on the real device as well.

So, my question is: how to set the UIView size so it follows best practices and, what is more important, GUI looks good on both Retina and older display.

BTW: I know how to deal with icons and graphics to make them look good on Retina and older display, I've read 开发者_开发百科all the relevant stackoverflow posts on the subject :)

Size is same on both standard and retina display. It's measured in points. Number of pixels depends on display density.

Pixel != point.

Look at UIScreen scale property. For standard screen it contains 1.0 and 2.0 for retina (iPhone 4). It can contain different values, even not integers.

If you set size UIImageView size to 100x100, it will have same physical size on standard and retina display. But on retina, it will show you much nicer image, because 100 points contains more pixels.

The units in Interface Builder are now interpreted as points not pixels. Therefore it will look the same on both types of displays. On old displays 1 point equates to 1 pixel. On Retina displays 1 point equates to 2 pixels.