在Swift中,如何调用Objective-C代码?
苹果提到它们可以共存于一个应用程序中,但这是否意味着人们可以在技术上重用Objective-C中创建的旧类,同时在Swift中构建新类?
在Swift中,如何调用Objective-C代码?
苹果提到它们可以共存于一个应用程序中,但这是否意味着人们可以在技术上重用Objective-C中创建的旧类,同时在Swift中构建新类?
当前回答
我写了一个简单的Xcode 6项目,展示了如何混合c++, Objective-C和Swift代码:
https://github.com/romitagl/shared/tree/master/C-ObjC-Swift/Performance_Console
特别地,这个例子调用了Swift中的Objective-C和c++函数。
关键是创建一个共享头文件Project-Bridging-Header.h,并将Objective-C头文件放在那里。
请下载该项目作为完整的示例。
其他回答
我还想补充一点:
我非常感谢@Logan的回答。创建桥文件和设置有很大帮助。
但是在做了所有这些步骤之后,我仍然没有在Swift中获得Objective-C类。
我使用cocoapods库并将其集成到我的项目中。也就是豆荚"pop"。
因此,如果你在Swift中使用Objective-C pod,那么可能有一个机会,你不能获得或导入类到Swift中。
你要做的一件简单的事情是:
转到<YOUR-PROJECT>-Bridging-Header文件和 将语句#import <ObjC_Framework>替换为@import ObjC_Framework
例如:(Pop library)
取代
#import <pop/POP.h>
with
@import pop;
当#import无效时使用clang import。
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.
你可以看看Swift & Cocoapods的帖子。基本上,我们需要创建一个桥接头文件,并将所有Objective-C头文件放在那里。然后我们需要从构建设置中引用它。之后,我们可以使用Objective-C代码。
let manager = AFHTTPRequestOperationManager()
manager.GET(
"http://example.com/resources.json",
parameters: nil,
success: { (operation: AFHTTPRequestOperation!,
responseObject: AnyObject!) in
println("JSON: " + responseObject.description)
},
failure: { (operation: AFHTTPRequestOperation!,
error: NSError!) in
println("Error: " + error.localizedDescription)
})
也可以看看苹果的文档Using Swift with Cocoa和Objective-C。
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。
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.