Margin and padding for UI elements in iOS

I have so far developed for Android. There, you can set layoutMargin and padding for almost every UI element (when you describe UI in xml file).

How is this done in code for UIV开发者_如何学Goiews in iOS (if there is a common command)?

Tnx

iOS employs a different approach to control placement - there's no layouting engine, you specify absolute coordinates and size for all controls. Kinda like the AbsoluteLayout in Android.

So the concepts of margin and padding don't really apply - the gaps between adjacent controls are completely up to you, they're not computed by the system. Same for sizes.

This makes it more difficult to implement the scenario of "make this control as large as it needs to be for its text". However, you won't run into rogue line wraps.

EDIT: AbsoluteLayout is deprecated these days.

You lay out your UI elements either in code or using Interface Builder (or the .xib editor in Xcode 4). You'll specify actual coordinates for your views, but you can also specify the resizing behavior for each view. So, you can say that a particular view should always keep the same size and remain horizontally centered, or that it should keep it's size and maintain the margin on the left, or that it should stretch to keep both left and right margins, etc. Look for the "autosizing" section in IB, or set the autoresizingMask property of any view in code.

In ios you can use Interface Builder for design. You can still use xml, but no one use this.