我花了大约 4 个小时试图在我的基于 Xcode Objective-C 的项目中启用 Swift.我的 myproject-Swift.h 文件已成功创建，但我的 Xcode 没有看到我的 Swift-classes.所以，我决定创建一个新的 Xcode 基于 Objc 的项目，最后，我找到了正确的答案！希望这篇文章能帮助别人:-)

基于 Xcode Objc 的项目的 Swift 分步集成:

1. 创建新的 *.swift 文件(在 Xcode 中)或使用 Finder 添加它.
2. 当 Xcode 询问您时，创建一个 Objective-C 桥接头.

3. 实现你的 Swift 类:

   导入基础//必要时使用@objc 或@objcMembers 注释类 Foo {//..}

4. 打开构建设置并检查这些参数:

   • 定义模块: YES

     复制&在搜索栏中粘贴参数名称

   • 产品模块名称: myproject

     确保您的产品模块名称不包含任何特殊字符

   • 安装 Objective-C 兼容性标题: YES

     将 *.swift 文件添加到项目后，此属性将出现在构建设置中

   • Objective-C 生成的接口头文件: myproject-Swift.h

     此标头由 Xcode 自动生成

   • Objective-C 桥接标题: $(SRCROOT)/myproject-Bridging-Header.h

5. 在 *.m 文件中导入 Swift 接口标头.

   #import "myproject-Swift.h"

   不要关注错误和警告.

6. 清理并重建您的 Xcode 项目.
7. 利润！

I try to integrate Swift code in my app.My app is written in Objective-C and I added a Swift class. I've done everything described here. But my problem is that Xcode haven't created the -Swift.h file, only the bridging headers. So I created it, but it's actually empty. I can use all my ObjC classes in Swift, but I can't do it vice versa. I marked my swift class with @objc but it didn't help. What can I do now?

EDIT: Apple says:" When you import Swift code into Objective-C, you rely on an Xcode-generated header file to expose those files to Objective-C. [...] The name of this header is your product module name followed by adding "-Swift.h". "

Now when I want to import that File, it gives an error:

    //MainMenu.m

    #import "myProjectModule-Swift.h" //Error: 'myProjectModule-Swift.h' file not found

    @implementation MainMenu

Here is my FBManager.swift file:

@objc class FBManager: NSObject {

    var descr = "FBManager class"

    init() {
        super.init()
    }

    func desc(){
        println(descr)
    }

    func getSharedGameState() -> GameState{
        return GameState.sharedGameState() //OK! GameState is written in Objective-C and no error here
    }
}

I spent about 4 hours trying to enable Swift in my Xcode Objective-C based project. My myproject-Swift.h file was created successfully, but my Xcode didn't see my Swift-classes. So, I decided to create a new Xcode Objc-based project and finally, I found the right answer! Hope this post will help someone :-)

Step by step Swift integration for Xcode Objc-based project:

1. Create new *.swift file (in Xcode) or add it by using Finder.
2. Create an Objective-C bridging header when Xcode asks you about that.

3. Implement your Swift class:

   import Foundation
   
   // use @objc or @objcMembers annotation if necessary
   class Foo {
       //..
   }
   

4. Open Build Settings and check these parameters:

   • Defines Module : YES

     Copy & Paste parameter name in a search bar

   • Product Module Name : myproject

     Make sure that your Product Module Name doesn't contain any special characters

   • Install Objective-C Compatibility Header : YES

     Once you've added *.swift file to the project this property will appear in Build Settings

   • Objective-C Generated Interface Header : myproject-Swift.h

     This header is auto-generated by Xcode

   • Objective-C Bridging Header : $(SRCROOT)/myproject-Bridging-Header.h

5. Import Swift interface header in your *.m file.

   #import "myproject-Swift.h"
   

   Don't pay attention to errors and warnings.

6. Clean and rebuild your Xcode project.
7. Profit!