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!
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 ...
}
@objc to its class definition, your code pops up the error "Unknown receiver ViewController" - if I add the #import "project-Swift.h" then the view controller is recognized in the first line of your code, but the second line shows error "No visible @interface for 'UIViewController' declares the selector 'runFunction'"
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 .
In your Objective file i.e. .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?
Use of undeclared identifier 'mainView'