title: Cannot access property from class
body: <pre><code>//MigrationVC.h
  #import &lt;Foundation/Foundation.h&gt;
  #import &lt;UIKit/UIKit.h&gt;
  
  @interface MigrationVC : UIViewController
  
  @end
  
  //MigrationVC.m
  #import "MigrationVC.h"
  
  @interface MigrationVC()
  @property (strong, nonatomic) IBOutlet UILabel *label;
  @property (strong, nonatomic) IBOutlet UIProgressView *progressView;
  
  @end
  
  @implementation MigrationVC
  
  @end
  
  //CoreData
  #import "CoreData.h"
  #import "MigrationVC.h"
  
  @interface CoreData()
  @property (nonatomic,retain) MigrationVC *migrationVC;
  @end
  
  -(void)obsererForKeyPath:(NSString*)keyPath object:(id)object change:(NSDictionary*)change context:(void*)context
  {
      if([keyPath isEqualToString:@"migrationProgress"])
      {
          dispatch_async(dispatch_get_main_queue(),^{
              float progress=[[change objectForKey:NSKeyValueChangeNewKey] floatValue];
              self.migrationVC.progress=progress;
          });
      }
  }
  </code></pre>
  
  <p>I am trying to learn CoreData and migration right now but this is giving me a quite a headache. </p>
  
  <p>I am trying to access the outlet properties from another classes but always gives red warning (Property 'label' not found on object of type MigrationVC*).</p>
  
  <p>I tried adding a NSString property in .h file which was accessible but when i tried to change the outlet from .m to .h file i couldn't ctrl+drag the view in the .h file. </p>
  
  <p>I never had this problem. I have accessed outlet from .m file many times in the past but it just gives me warning now.
  How can i access the properties while outlet in .m file?</p>
  
  <p><a href="https://i.stack.imgur.com/1Z7jq.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/1Z7jq.png" alt="The problem is i can&#39;t add the outlet in .h file"></a></p>
  
  <p>I cannot outlet the properties in .h file.</p>