Swift:如何为静态库创建外部接口(Objective-C .h中的公共头类)

I need to create a static library with Swift, and I need to know how can I implement interface for the library.

我需要用Swift创建一个静态库，我需要知道如何实现库的接口。

In Objective-C I can mark needed headers as public in build phases, but there is not any headers and any interfaces in Swift.

在Objective-C中，我可以在构建阶段将需要的头标为public，但是在Swift中没有任何头标和接口。

What should I do with Swift?

我该怎么处置斯威夫特?

2 个解决方案

#1

Simply put: you don't.

简单的说:你不喜欢。

Swift is not a language that separates headers and implementations. When you create a library or framework based on Swift and only for consumption by Swift, the Xcode default build setting of DEFINES_MODULE already does the job for you. This will create a .swiftmodule file, which will be used by import in other Swift projects.

Swift不是一种区分头和实现的语言。当您基于Swift创建一个库或框架并仅供Swift使用时，DEFINES_MODULE的Xcode默认构建设置已经为您完成了这项工作。这将创建一个.swiftmodule文件，它将被导入到其他Swift项目中。

If you want your code to be importable from Objective-C though, you might want to check if the SWIFT_INSTALL_OBJC_HEADER build setting is also enabled (which it is by default for frameworks as far as I know). Then the Swift compiler will generate a <ProductName>-Swift.h file for you, which you can import in Objective-C code to access your Swift classes and functions.

如果您希望您的代码可以从Objective-C中导入，那么您可能需要检查SWIFT_INSTALL_OBJC_HEADER构建设置是否也被启用(据我所知，这是框架的默认设置)。然后，Swift编译器将生成一个 -Swift。h文件，你可以导入Objective-C代码来访问你的Swift类和函数。

#2

If you want your Swift framework to expose certain classes to the interface, simply mark the 'entities' (functions, variables etc.) public:

如果您希望您的Swift框架向接口公开某些类，只需将“实体”(函数、变量等)标记为public:

public class Class {}
public var variable: Int
public func function() { }

By default, all entities have internal access.

默认情况下，所有实体都具有内部访问权限。

public entities are intended for use as API, and can be accessed by any file that imports the module, e.g. as a framework used in several of your projects.
公共实体的目的是用作API，并且可以通过导入模块的任何文件访问，例如在几个项目中使用的框架。
internal entities are available to the entire module that includes the definition (e.g. an app or framework target).
包括定义的整个模块(例如，应用程序或框架目标)都可以使用内部实体。
private entities are available only from within the source file where they are defined.
私有实体只能在定义它们的源文件中使用。

Source: the official Swift blog.

资料来源:Swift官方博客。

#1