title: How to Set Alpha or opacity in old view only before addsubView
body: <p>I don't know, How to set old view in interface to decrease alpha in old view only</p>
  
  <p>not decrease New view</p>
  
  <p>i have this function</p>
  
  <pre><code>-(IBAction)save:(id)sender
  {
      testView * subTestview = [[testView alloc]initWithNibName:@"TestView" bundle:nil];
      subTestview.view.frame = CGRectMake(0, 0, subTestview.view.frame.size.width,
                                          subTestview.view.frame.size.height);
      subTestview.view.center = CGPointMake(self.view.frame.size.width/2, self.view.frame.size.height/2);
      self.view.alpha = 0.3f;
      [self.view addSubview:subTestview.view];
  }
  </code></pre>
  
  <p>when i use "self.view.alpha = 0.3f", it decrease alpha of all view</p>
  
  <p>Help me please</p>
  
  <p>Thank you</p>
  
  <p>Ton</p>