Swift 和 OC 混编之 framework

在主工程为 Swift 的 framework 中引用 OC 代码

Import Code Within a Framework Target

To use the Objective-C declarations in files in the same framework target as your Swift code, you’ll need to import those files into the Objective-C umbrella header—the master header for your framework. Import your Objective-C files by configuring the umbrella header:

Under Build Settings, in Packaging, make sure the Defines Module setting for the framework target is set to Yes.

In the umbrella header, import every Objective-C header you want to expose to Swift.

Swift sees every header you expose publicly in your umbrella header. The contents of the Objective-C files in that framework are automatically available from any Swift file within that framework target, with no import statements. Use classes and other declarations from your Objective-C code with the same Swift syntax you use for system classes.

官方文档里说明了这一点，将所有需要暴露给 Swift 的 Objective-C 文件都放在 umbrella header中（在 framework中，umbrella 文件可以理解为 framework 默认生成的.h 文件,详细解释请看下文）

umbrella header

umbrella header - iOS framework or library on Objective-C can have a header file that contains references to all the other headers in that project.

When you create a framework target Xcode will automatically generate <targer_name.h> file. It should has the same name as Product Name

Build Settings:

Product Name - default value is $(TARGET_NAME:c99extidentifier)
Product Module Name - default value is (PRODUCT_NAME:c99extidentifier)

For example <umbrella_name.h> looks like

#import "header_1.h"     #import "header_2.h"
As a result you can use the next syntax

#import <umbrella_name.h>
instead of

#import <header_1.h>
#import <header_2.h>

Also umbrella header is also required by the typical module map structure

On practice when you create a Framework on Objective-C or Swift this file will be created automatically with <product_name>

举个栗子

1. 拖入一个 Masonry 的源文件到工程中，创建一个测试用的ViewController

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2. 在 umbrella header（SwiftDemo.h） 中放入需要暴露给 Swift 的头文件

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3. 修改Build Phases 中暴露出去的头文件为 Public

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4.调用

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优缺点

优点

Objective-C 中的相应 API 可以直接在 Swift 中使用，而且不需要 import

缺点

如果项目中使用的是一个模块，不是一个文件的话，那么在引用的时候所有的头文件都需要暴露