XCode样板代码混乱，为什么会添加多次？
程序员们大家好，
让我们直接讨论我注意到的一些问题。我正在清理我的代码并了解 Xcode 生成了多少样板代码。我发现了一些不寻常的东西，在我的前缀文件中（假设你们所有人也必须有这个...）我有一些这样的代码，
[图像 1.1]
在图像 1.1 中我们可以清楚地看到，如果定义是 Objective C，则 #import。这将节省我们在所有其他类中重写 #import 语句，因为根据定义，此导入将可用于我们项目中的所有 Objective C 类。（我可能是错的，如果我错了，请用砖头打我！:)） 。
但是，每当您添加类或选择 ViewBased 应用程序（或其他...）时，都会有一些已经为您创建的类，其中包含大量的样板代码，包括 ##
[Image 1.2]
正如我们在 Image 1.2 中看到的，Xcode 再次添加了 import 语句，所以我的困惑是，
我无法理解
- 为什么 Xcode 多次添加#import？
- 我们真的需要 #import 两次吗？
- 我应该担心这个还是闭嘴并开始制作很棒的应用程序？
感谢您的输入
G'Day Programmers,
Lets get straight onto some of the issues I noticed. I was cleaning up my code and learning how much boilerplate code is being generated by Xcode. I found something unusual, In my prefix file(Assuming all of you must have this too...) I have some code like this,
[Image 1.1]
In Image 1.1 we can clearly see that, If definition is Objective C than #import <UIKit/UIKit.h>. This will save us rewriting #import statement in all our other classes because by definition this import will be available to all Objective C classes in our project.(I might be wrong, Please hit me with the brick if I am wrong! :) ).
However, Whenever you add a classes or when you choose ViewBased application(or whatever...) there will be few classes already created for you with awesome amount of boilerplate code including #<UIKit/UIKit.h> like,
[Image 1.2]
As we can see in Image 1.2 Xcode again added import statement, So my confusion is,
I can't understand
- Why Xcode is adding #import multiple times?
- Do we really need to #import twice?
- Should I worried about this or shut up and start making awesome apps?
Thanks for you input
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它可能包含两次，因此如果您决定禁用前缀标头，它不会破坏您的代码。
It's likely included twice so that if you decide to disable the prefix header it won't break your code.
您会多次导入同一内容，因为 Xcode 模板的质量参差不齐。有些很好，有些则不太好。它们是由往往并不完美的人编写的。
您实际上不必担心，因为 #import 会阻止标头被多次包含。
您也不需要 #import 两次，因为它只包含一次。
You get multiple imports of the same thing because the Xcode templates are of uneven quality. Some are good, some are not so good. They're written by people, who tend not to be perfect.
You don't really need to worry as #import prevents headers from being included more than once.
You also don't need to #import twice as it's only being included once.