"unknown type name import" error in iOS

Question

I Had tried to include swift ViewController File in to Objective-C project but i unable to do it, it shows error like unknown type name import how to solve this please any one help for this issue.

Here I Send my Code and ScreenShot.

import UIKit
@objc class SigViewController2: UIViewController {

@IBOutlet weak var cameraBtn: UIButton!

@IBOutlet weak var imageBtn: UIButton!

@IBOutlet weak var settingsBtn: UIButton!

@IBOutlet weak var mediaBtn: UIButton!


override func viewDidLoad() {
    super.viewDidLoad()

    // Do any additional setup after loading the view, typically from a nib.
}
override func viewWillAppear(animated: Bool) {
    super.viewWillAppear(true)
    navigationController?.navigationBarHidden = false

    self.navigationItem.title = "Main";
}
override func supportedInterfaceOrientations() -> UIInterfaceOrientationMask {

    // Only allow Portrait
    return UIInterfaceOrientationMask.Portrait
}

override func preferredInterfaceOrientationForPresentation() -> UIInterfaceOrientation {

    // Only allow Portrait
    return UIInterfaceOrientation.Portrait
}

Answer 1

For Developers still looking for answer.
Importing Swift file inside Objective-c can cause this error, if it doesn't import properly.

---

Let's look at the the error first.

Let's try above KJTreeObjC.Swift file inside below Objective-C ViewController.

---

Solution:

You've to import it with the help of bridging header.
When you Created/Copied Swift file inside Objective-C project. It would've created a bridging header automatically.

Check Objective-C Generated Interface Header Name at Targets -> Build Settings.

That's the header name we will Import now.
You can check afterwards, error would've been gone instantly.

Answer 2

This error is showing because you have imported .swift class in your Objective-C ViewController. This is wrong and you should import Swift header, instead:

#import "ProductModuleName-Swift.h"

Answer 3

In my case, it was because somehow the selected type in the file inspector was objective-c source instead of Default - Swift Source even though i was using a .swift file.

Changing it to Default - Swift Source solved the issue for me.