title: Change Navigation bar Background image on each navigation
body: <p>I am working on iPhone app. I have added Navigation bar Background image</p>
  
  <p>With interface: -</p>
  
  <p><code>@interface UINavigationBar (backgroundImageWithTitle)</code></p>
  
  <p>And method: -</p>
  
  <p><code>- (void)drawRect:(CGRect)rect</code></p>
  
  <p>By this method Navigation bar background images is being set one time.</p>
  
  <p>I want to call it from different <code>.m</code> files for assigning different images on bar.</p>
  
  <p>How it can be implemented? </p>
  
  <p>Thanks in advance.</p>