Create a .h file from NewFile -> Source -> header file Then save the name of file Your_Target_Name-Bridging-Header.h People here gets common mistake by taking their project name but it should be the Project's Target's name if in case both are different, generally they are same. Then in build settings search for Objective-C Bridging Header flag and put the address of your newly created bridging file, you can do it right click on the file -> show in finder -> drag the file in the text area then the address will be populated. Using #import Your_Objective-C_file.h In the swift file you can access the ObjC file but in swift language only.

引用自文档:

Any Objective-C framework (or C library) that’s accessible as a module can be imported directly into Swift. This includes all of the Objective-C system frameworks—such as Foundation, UIKit, and SpriteKit—as well as common C libraries supplied with the system. For example, to import Foundation, simply add this import statement to the top of the Swift file you’re working in: import Foundation This import makes all of the Foundation APIs—including NSDate, NSURL, NSMutableData, and all of their methods, properties, and categories—directly available in Swift.

给那些试图将Objective-C库添加到Swift的人一个提示:你应该在构建设置中添加- objc ->链接->其他链接器标志。

混合Objective-C和Swift

高层图:

相同的目标

//Objective-C exposes API for Swift thought <target_name>-Bridging-Header.h
.swift uses .h.m = Swift consumer, Objective-C producer = <target_name>-Bridging-Header.h

//Swift exposes API for Objective-C thought <target_name>-Swift.h
.h.m uses .swift = Objective-C consumer, Swift producer = <target_name>-Swift.h

Swift消费者，Objective-C生产者

添加一个新的头文件。h和实现文件。m - Cocoa类文件(Objective-C) 例如<MyFileName>.h和<MyFileName>.m 配置桥接报头 当您看到“是否想配置Objective-C桥接头”时，单击“是” <target_name>-Bridging-Header.h将自动生成 构建设置-> Objective-C桥接头(SWIFT_OBJC_BRIDGING_HEADER) 将类添加到桥接头 在<target_name>-Bridging-Header.h中添加一行#import "<MyFileName>.h"

之后你可以使用Swift Objective-C的MyFileName.h,MyFileName.m

附注:如果你要添加一个现有的Objective-C文件到Swift项目中，请预先添加Bridging-Header.h并导入它

Objective-C消费者，Swift生产者

添加一个<MyFileName>.swift和extends NSObject 将Swift文件导入ObjC类 在Objective-C文件中添加#import "<target_name>-Swift.h" 通过@objc公开Swift代码[关于]

在此之后，您可以使用Objective-C Swift的<MyFileName>.swift

[<product_name>-Swift.h文件未找到]

不同的目标 (。modulemap]和[伞盖.h]用于暴露Objective-C for Swift。Swift.h用于为Objective-C公开Swift代码

(词汇)

在Xcode 10.1中的Swift 4.2.1项目中，您可以轻松地添加Objective-C文件。按照以下步骤将Objective-C文件连接到Swift项目。

Step_01:使用Swift语言创建新的Xcode项目:

文件>新建>项目> objc。

在Swift项目中添加新的Objective-C文件:

File >新建>文件…> macOS > Objective-C文件。

Step_03:如果你第一次添加一个新的Objective-C文件到Swift项目中，Xcode会问你:

你想配置一个Objective-C桥接头吗?

Step_04:选择选项:

创建桥接头。

Step_05:将生成一个对应的文件，文件的名称如下:

Objc-Bridging-Header.h。

Step_06:现在，你需要在桥标头中设置桥文件路径。在项目导航器中单击名称为objc的项目，然后选择:

> Objective-C桥接头> objc桥接头。h

将Objc-Bridging-Header.h拖放到该框中生成文件路径。

打开你的Objc-Bridging-Header.h文件，并导入你想要在Swift文件中使用的Objective-C文件。

#import "SpecialObjcFile.m"

下面是SpecialObjcFile.m的内容:

#import <Foundation/Foundation.h>

@interface Person: NSObject {
@public
    bool busy;
}
@property
    bool busy;
@end

现在在你的Swift文件中，你可以使用一个Objective-C类:

override func viewDidLoad() {
    super.viewDidLoad()
    let myObjcContent = Person()
    print(myObjcContent.busy)
}

以下是在Swift项目中使用Objective-C代码(在这种情况下，由第三方提供的框架)的逐步说明:

通过选择file -> New -> New file -> Objective-C file将任何Objective-C文件添加到Swift项目中。保存时，Xcode会询问你是否想要添加一个桥接头。选择“是”。 (来源:derrrick.com)

步骤简单:

A prompt appears, and then click on OK... If it does not appear, then we create it manually like in the following... Create one header file from iOS source and give the name ProjectName-Bridging-Header (example: Test-Bridging-Header), and then go to build setting in the Swift compiler code -> Objective-C bridge add Objective-C bridge name ..(Test/Test-Bridging-Header.h). Yeah, that's complete. Optionally, delete the Objective-C file you added (named "anything" in the GIF image above). You don't need it any more. Open the bridging header file -- the filename is of the form [YourProject]-Bridging-Header.h. It includes an Xcode-provided comment. Add a line of code for the Objective-C file you want to include, such as a third-party framework. For example, to add Mixpanel to your project, you will need to add the following line of code to the bridging header file: #import "Mixpanel.h" Now in any Swift file you can use existing Objective-C code, in the Swift syntax (in the case of this example, and you can call Mixpanel SDK methods, etc.). You need to familiarize yourself with how Xcode translates Objective-C to Swift. Apple's guide is a quick read. Or see this answer for an incomplete summary.

Mixpanel的示例:

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
    Mixpanel.sharedInstanceWithToken("your-token")
    return true
}

就是这样!

注意:如果你从你的项目中删除桥接头文件，请确保进入构建设置并在“Swift Compiler - Code Generation”下删除“Objective-C桥接头”的值。