请解释这个目标C code [英] Please explain this Objective-C code

问题描述

ref1view.hidden = NO;
[UIView beginAnimations:nil context:nil];
[UIView setAnimationDuration:0.25f];
[ref1view setAlpha:([ref1view alpha] == 1.0f) ? 0.0f : 1.0f];
[UIView commitAnimations];

任何人都可以请给我如何工作的细分？特别是这一行：

Can anyone please give me a breakdown of how this works? Specifically this line:

[ref1view setAlpha:([ref1view alpha] == 1.0f) ? 0.0f : 1.0f];

看来，这个功能会从0-1 1-0从动画的alpha和回来，我只是不明白的语法。
谢谢！

It seems that this function will animate the alpha from 0-1 and back from 1-0 and I just don't understand the syntax. Thanks!

推荐答案

[ref1view setAlpha：（[ref1view阿尔法] == 1）？ 0.0：1.0F]; ：

设定 ref1view 为1，如果是0，或者0，如果是1，这就是所谓的三元运算符的简写的字母的if-else 。

Sets the alpha of ref1view to be 1 if it's 0, or 0 if it's 1. This is called the ternary operator, a shorthand if-else.

(condition) ? conditionistrue : conditionisfalse;

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