title: How to get UIVisualEffectView to fade in animated?
body: <p>I have a view that I want to cover with a blur and have it animate in. I added the UIVisualEffectView called blurField in storyboard. This is what I hacked together, is there a cleaner way to do this? Thanks!</p>
  
  <pre><code>-(void)viewDidLoad {
      [super viewDidLoad];
      self.blurField.alpha = 0.0;
      [self performSelector:@selector(fillInBlur) withObject:nil afterDelay:3.0];
  }
  
  -(void)fillInBlur {
      self.blurField.alpha = 0.1;
      [self performSelector:@selector(fillInBlur1) withObject:nil afterDelay:0.03];
  }
  
  -(void)fillInBlur1 {
      self.blurField.alpha = 0.2;
      [self performSelector:@selector(fillInBlur2) withObject:nil afterDelay:0.03];
  }
  
  -(void)fillInBlur2 {
      self.blurField.alpha = 0.3;
      [self performSelector:@selector(fillInBlur3) withObject:nil afterDelay:0.03];
  }
  
  -(void)fillInBlur3 {
      self.blurField.alpha = 0.4;
      [self performSelector:@selector(fillInBlur4) withObject:nil afterDelay:0.03];
  }
  
  -(void)fillInBlur4 {
      self.blurField.alpha = 0.5;
      [self performSelector:@selector(fillInBlur5) withObject:nil afterDelay:0.03];
  }
  
  -(void)fillInBlur5 {
      self.blurField.alpha = 0.6;
      [self performSelector:@selector(fillInBlur6) withObject:nil afterDelay:0.03];
  }
  
  -(void)fillInBlur6 {
      self.blurField.alpha = 0.7;
      [self performSelector:@selector(fillInBlur7) withObject:nil afterDelay:0.03];
  }
  
  -(void)fillInBlur7 {
      self.blurField.alpha = 0.8;
      [self performSelector:@selector(fillInBlur8) withObject:nil afterDelay:0.03];
  }
  
  -(void)fillInBlur8 {
      self.blurField.alpha = 0.9;
      [self performSelector:@selector(fillInBlur9) withObject:nil afterDelay:0.03];
  }
  
  -(void)fillInBlur9 {
      self.blurField.alpha = 1.0;
  }
  </code></pre>