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。

登录的答案工作良好，除了在最新的Swift 5，它给出了一些编译器错误。以下是针对Swift 5开发人员的修复。

斯威夫特5

import Foundation

class MySwiftObject : NSObject {

    var someProperty: AnyObject = "Some Initializer Val" as AnyObject

    override init() {}

    func someFunction(someArg:AnyObject) -> String {
        let returnVal = "You sent me \(someArg)"
        return returnVal
    }
}

在Swift中使用Objective-C类

如果您有一个想要使用的现有类，请执行步骤2，然后跳到步骤5。(在某些情况下，我必须在旧的Objective-C文件中添加显式的#import <Foundation/Foundation.h。)

步骤1:添加Objective-C实现——.m

向类中添加一个.m文件，并将其命名为CustomObject.m。

步骤2:添加桥接头

当添加你的.m文件时，你可能会看到这样的提示:

单击Yes !

如果你没有看到提示，或者不小心删除了桥接头，添加一个新的。h文件到你的项目，并命名为<#YourProjectName#>-Bridging-Header.h。

在某些情况下，特别是在使用Objective-C框架时，你没有显式地添加Objective-C类，Xcode就找不到链接器。在这种情况下，创建如上所述的.h文件，然后确保将其路径链接到目标项目设置中，如下所示:

注意:

使用$(SRCROOT)宏链接您的项目是最好的做法，这样如果您移动您的项目，或使用远程存储库与他人一起处理它，它仍然可以工作。$(SRCROOT)可以被认为是包含.xcodeproj文件的目录。它可能是这样的:

$(SRCROOT)/Folder/Folder/<#YourProjectName#>-Bridging-Header.h

步骤3:添加Objective-C Header——.h

添加另一个.h文件并将其命名为CustomObject.h。

步骤4:构建Objective-C类

在CustomObject.h

#import <Foundation/Foundation.h>

@interface CustomObject : NSObject

@property (strong, nonatomic) id someProperty;

- (void) someMethod;

@end

在CustomObject.m

#import "CustomObject.h"

@implementation CustomObject 

- (void) someMethod {
    NSLog(@"SomeMethod Ran");
}

@end

步骤5:添加类到桥接头

在YourProject-Bridging-Header.h:

#import "CustomObject.h"

第六步:使用你的对象

在SomeSwiftFile.swift:

var instanceOfCustomObject = CustomObject()
instanceOfCustomObject.someProperty = "Hello World"
print(instanceOfCustomObject.someProperty)
instanceOfCustomObject.someMethod()

不需要显式地导入;这就是桥接头的作用。

在Objective-C中使用Swift类

步骤1:创建新的Swift类

添加一个.swift文件到你的项目中，并将其命名为MySwiftObject.swift。

在MySwiftObject.swift:

import Foundation

@objc(MySwiftObject)
class MySwiftObject : NSObject {

    @objc
    var someProperty: AnyObject = "Some Initializer Val" as NSString

    init() {}

    @objc
    func someFunction(someArg: Any) -> NSString {
        return "You sent me \(someArg)"
    }
}

步骤2:将Swift文件导入ObjC类

在SomeRandomClass.m:

#import "<#YourProjectName#>-Swift.h"

文件:<#YourProjectName#>-Swift.h应该已经在你的项目中自动创建了，即使你看不到它。

第三步:利用你的课程

MySwiftObject * myOb = [MySwiftObject new];
NSLog(@"MyOb.someProperty: %@", myOb.someProperty);
myOb.someProperty = @"Hello World";
NSLog(@"MyOb.someProperty: %@", myOb.someProperty);

NSString * retString = [myOb someFunctionWithSomeArg:@"Arg"];

NSLog(@"RetString: %@", retString);

注:

If Code Completion isn't behaving as you expect, try running a quick build with ⌘⇧R to help Xcode find some of the Objective-C code from a Swift context and vice versa. If you add a .swift file to an older project and get the error dyld: Library not loaded: @rpath/libswift_stdlib_core.dylib, try completely restarting Xcode. While it was originally possible to use pure Swift classes (Not descendents of NSObject) which are visible to Objective-C by using the @objc prefix, this is no longer possible. Now, to be visible in Objective-C, the Swift object must either be a class conforming to NSObjectProtocol (easiest way to do this is to inherit from NSObject), or to be an enum marked @objc with a raw value of some integer type like Int. You may view the edit history for an example of Swift 1.x code using @objc without these restrictions.

点击新建文件菜单，并选择文件选择语言目标。这时，它会自动生成一个“Objective-C Bridging Header”文件，用于定义一些类名。

“Swift编译器-代码生成”下的“Objective-C桥接头”。

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.

使用objective-c的双向方法

1

在Xcode Project中创建bridge-header.h文件 在bridge-Header文件中导入.h文件 在Build设置中设置bridge-Header的路径。 清理项目

2

在项目中创建objective-c文件(它会自动在Build Settings中为您设置路径) 在bridge-Header文件中导入.h文件

现在可以开始了 谢谢