We are trying to reference Swift methods inside an Objective-C implementation.
Swift class:
import Foundation
@objc class MySwiftClass: NSObject {
override init() {
super.init()
}
func sayHello() -> Void {
print("hello");
}
func addX(x:Int, andY y:Int) -> Int {
return x+y
}
}
Objective-C implementation (Objective-c.m):
#import "ProductModuleName-Swift.h"
MySwiftClass* getData = [[MySwiftClass alloc]init];
[getData sayHello] //works
[getData addX:5 addY:5] //No visible @interface for 'MySwiftClass' declares selector 'addX:addY'
The last line of code gives the following error:
No visible @interface for 'MySwiftClass' declares selector 'addX:addY'
If you command-click on "ProductModuleName-Swift.h"
in the Xcode
source file editor then you can see how the Swift methods are mapped to Objective-C.
In your case that would be
@interface MySwiftClass : NSObject
- (nonnull instancetype)init OBJC_DESIGNATED_INITIALIZER;
- (void)sayHello;
- (NSInteger)addXWithX:(NSInteger)x andY:(NSInteger)y;
@end
which is called as
MySwiftClass* getData = [[MySwiftClass alloc]init];
[getData sayHello];
NSInteger result = [getData addXWithX:5 andY:5];
A better Swift 3 method name might be
func add(x: Int, y:Int) -> Int
because x
is already the argument (external) name of the first
parameter. You can also add an @objc()
attribute to the Swift definition
to control the Objective-C name. For example, with
@objc(addX:andY:)
func add(x: Int, y: Int) -> Int {
return x+y
}
it would be called from Objective-C as
NSInteger result = [getData addX:5 andY:5];