在Objective-C中调用swift视图控制器文件的变量

Question

I have a project that is a cross of Swift and Objective-C using a bridging-header.

In my main ViewController.swift file, outside of the class declaration, I have this code:

var mainView = ViewController()

In other views that I segue to, I can use this to call a function to run back on the main ViewController by using mainView.runFunction()

How can I call this function in an Objective-C .m implementation file?

Thanks!

Answer 1

First of all for using swift in objective-c you need to import TargetName-Swift.h . Note that it's the target name.

For more information look at this .

You can achieve what you want in this way:

ViewController *mainView = [[UIViewController alloc] init];
[mainView runFunction];

Also you should declare your runFunction with @objc to use it in objective-c like below:

@objc func runFunction {
    // what you want to do ...
}

Answer 2

Follow this apple article and done : Load Swift in Objective-C . Or I already did is a "trick" using "@objc" key, look at this little explanation: What is @objc attribute , one easy way is just create a helper function that will be visible to your Objective-c class and done like:

@objc func retrieveMainView() -> UIViewController { return MyViewController() }

And you call this from your objective-c class, maybe you need to anotate your swift class with @objc, look at this two reference and you will get the idea and figure out for sure .

Answer 3

In your Objective file ie .m file add below import statement:

import "<ProjectName>-Swift.h"

For example your project name is MyProject, so import statement would look like:

import "MyProject-Swift.h"

And call your function like: [mainView runFunction];

I hope this will help. You can also refer one of my answer: How can I import Swift code to Objective-C?