ios - UIButton - alloc initWithFrame: vs. buttonWithType:

Question

Given (arbitrarily):

CGRect frame = CGRectMake(0.0f, 0.0f, 100.0f, 30.0f);

What's the difference between the following two code snippets?

1.

    UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
    button.frame = frame;

2.

    UIButton *button = [[[UIButton alloc] initWithFrame:frame] autorelease];

Answer 1

I think they're equivalent. Haha! Trick question you sneaky little punk!

Reasoning

1. -buttonWithType: returns an autoreleased UIButton object.

2. +[NSObject alloc] defaults scalar instance variables to 0, so buttonType should be 0, or UIButtonTypeCustom.

Pros & Cons

1. You could argue that it's clearer to use -buttonWithType: and set buttonType explicitly and that it's safer in case Apple changes UIButtonTypeCustom to be 1 instead of 0 (which will most certainly never happen).

2. On the other hand, you could also argue that it's clear & safe enough to use -initWithFrame. Plus, many of the Xcode sample projects, such as "TheElements" & "BubbleLevel," use this approach. One advantage is that you can explicitly release the UIButton before the run loop for your application's main thread has drained its autorelease pool. And, that's why I prefer option 2.