Cannot call Swift method in Objective-C .m file - ios

Question

I have big problem with one part of my code.
I have simple function in my ViewController.swift file (on end):
ViewController.swift
#objc class Constant: NSObject {
override init() {}
#objc class func parseApplicationId() -> String { return "lol" }
#objc func printSome() { print("teeeeest") }
}
Now I have one pod (charts graphic) what was written in Objective-C. So I created Bridging file called:
myprojectname-Swift.h
#import "EColumnChartViewController.h"
In header file of Objective-C file:
HEADER.h
#import <UIKit/UIKit.h>
#import "EColumnChart.h"
#import "myprojectname-Swift.h"
#class Constant;
#interface Constant : NSObject
-(void)printSome;
#end
and in my FILE.m I have this:
#import "myprojectname-Swift.h"
- (void)viewDidLoad
{
[super viewDidLoad];
Constant * sis = [[Constant alloc] init];
[sis printSome];
}
My problem is:
When I build a project, Xcode call me error:
Undefined symbols for architecture x86_64:
"_OBJC_CLASS_$_Constant", referenced from:
objc-class-ref in EColumnChartViewController.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
What I trying to make solution:
New Bridging file
Switching off some parts of Build Settings
#implementation Constant -> Thread 1 error
I just want to call Swift function into Objective-C file (easy call print console). Thanks for every idea.
Last words: I've checked so many posts on Stackoverflow.

Answer 1

Duplicate classes
The main issue appears to be that you have created two classes named Constant: one in Swift and another in Objective-C. You can only have one class with a given name.
This #objc class Constant: NSObject and #interface Constant : NSObject both create the same class. Rename one of these.
Possibly incorrect bridging
The Swift bridging header is special. You can't just create a header file and expect that to work in Swift.
Ensure that the bridging header is properly set in Xcode.
Click the project at the top to open the config screen
Search for SWIFT_OBJC_BRIDGING_HEADER
Make sure the value points to your bridging header. For example: myprojectname/myprojectname-Bridging-Header.h
In the bridging header file, put the Objective-C import for the class that you want Swift to be able to use: #import "EColumnChartViewController.h"
Other Issues
In HEADER.h:
remove #class Constant;. This is doing nothing for you.
Move the #import for EColumnChart.h and myprojectname-Swift.h into the .m file only.
The FILE.m should have an #import HEADER.h. Every .m must import it's .h!
On the line #objc class Constant: NSObject, remove the #objc... it's obviously Objective-C because it extends NSObject.
As some commenters have stated, you have provided code with an astonishing number of problems. You should really take the time to learn Objective-C and/or Swift first. Start by watching some of the free WWDC videos or Googling for intro to iOS.

Answer 2

Make step by step above
You use #objcMembers above declare class in swift file.
Import <"Your_Project">-Swift.h in .m file.
objcMembers
class ObjectA: NSObject {
.....
}