什么是伞头？ [英] What is an umbrella header?

问题描述

什么是伞头？有什么用？我收到了一个警告，如下所示。这是什么意思？

What is basically an umbrella header? What is its use? I got a warning as shown below. What does this mean?

<module-includes>:1:1: warning: umbrella header for module 'XCTest' does not include header 'XCTextCase+AsynchronousTesting.h' [-Wincomplete-umbrella]
#import "/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/Library/Frameworks/XCTest.framework/Headers/XCTest.h"

推荐答案

umbrella标题是框架的主头文件。它的用途是你可以写

The umbrella header is the 'master' header file for a framework. Its use is that you can write

#import <UIKit/UIKit.h>

而不是

#import <UIKit/UIViewController.h>
#import <UIKit/UILabel.h>
#import <UIKit/UIButton.h>
#import <UIKit/UIDatePicker.h>

等等。

对我来说，< XCTest / XCTestCase + AsynchronousTesting.h> 包含在< XCTest / XCTest.h> 中。也许它不适合你？在这种情况下，添加

For me, <XCTest/XCTestCase+AsynchronousTesting.h> is included in <XCTest/XCTest.h>. Maybe it is not for you? In that case, add the

#import <XCTest/XCTestCase+AsynchronousTesting.h>

手动。

这篇关于什么是伞头？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！