使用xib和通过代码添加之间的区别 - iPhone

Question

What is the difference between using xib and adding page elements via code?

How the memory is allocated if I am using an xib?

Answer 1

What is the difference between using xib and adding page elements via code?

The only real difference I know about is that using code is awesome and is recommended for beginners in order them to understand how UIKit works.

How the memory is allocated if I am using an xib?

Just like as if you were creating the objects manually, except that, for example, it won't be your view controller that performs [[UIImageView alloc] init] but a default factory class in UIKit (most likely some private subclass of NSCoder ).

Answer 2

There is one major non-obvious difference between using XIB versus code for object creation/layout: Interface Builder does not offer settings for every property of every interface class type -- for some properties you just need to use code.

Some things are difficult/cumbersome or even impossible to do in interface builder, but are trivial to do in code. Back at least in the ios3/4 days, setting up a navigation controller along with customizing its title bar in interface builder was a real pain -- I always used code for this.

Answer 3

Since a XIB consists of serialized objects and nothing more, using the Interface Builder or implementing the interface objects in code is not going to make a difference in memory usage once the objects are allocated. Each method has its advantages and disadvantages. Primarily, you may find that you have more control over the interface's behavior and appearance by creating interface objects in code. Whereas working with the Interface Builder can make the task of laying out objects easier due to its graphical interface.