call swift delegate in obj-c - ios

Question

I am trying to port an old obj-c application to swift, and in the process restructure and reprogramm everything. Some things need to be portet at a later point and I have to use old obj-c in swift, which isn't a problem, but I ran into a serious issue which seems like i cannot solve.
I have a obj-c "connection" class which is called from a swift wrapper. The problem is, i cannot pass the delegate object to obj-c or at least i dont know how.
Here is my code:
//swift protocol
#objc protocol ConnectionDelegate
{
#objc func connected() -> Void
}
//swift class
#objc class ConnectionManager : NSObject, ConnectionDelegate
{
var connectionThread : ConnectionThread
init(){
connectionThread.inti()
connectionThread.registerDelegate(self) //Value of type 'ConnectionThread' has no member of 'registerDelegate'
connectionThread.testFunc() //all ok
}
#objc func connected(){
}
}
//obj-c header ConnectionThread.h
#class ConnectionDelegate;
#property (nonatomic, weak) ConnectionDelegate* delegate;
-(void) registerDelegate: (ConnectionDelegate*) delegate;
-(void) testFunc;
//obj-c class ConnectionThread.h
#import ".....Swift.h"
#synthesize delegate;
-(void) registerDelegate:(ConnectionDelegate*) delegate
{
self.delegate = delegate;
}
-(void) testFunc
{
}

Answer 1

In the future, please copy and paste your actual code into your question. The code in your question is full of errors, which means it isn't your real code, and those errors might make it impossible to answer your question correctly.
So, assuming you haven't made too many errors in the code you posted, the problem is that you are lying to the compiler. Specifically, your Objective-C header file ConnectionThread.h says this:
#class ConnectionDelegate;
But ConnectionDelegate is not a class. It is a protocol, so you need to declare it as a protocol. Then you will also have to use the proper Objective-C syntax for a type that conforms to the protocol, which is id<ConnectionDelegate>.
// ConnectionThread.h
#import <Foundation/Foundation.h>
NS_ASSUME_NONNULL_BEGIN
#protocol ConnectionDelegate;
#interface ConnectionThread : NSObject
#property (nonatomic, weak) id<ConnectionDelegate> delegate;
- (void)registerDelegate:(id<ConnectionDelegate>)delegate;
#end
NS_ASSUME_NONNULL_END
// ConnectionThread.m
#import "ConnectionThread.h"
#implementation ConnectionThread
- (void)registerDelegate:(id<ConnectionDelegate>)delegate {
self.delegate = delegate;
}
#end