title: Change the size of UISlider thumb in Swift
body: <p>I am new to Swift. I have a <code>UISlider</code> and I want to make the size of the <strong>thumb of UISlider</strong> to smaller.</p>
  
  <p>I tried to set a smaller image using code :</p>
  
  <pre><code>self.setThumbImage(UIImage(named: "progress_thumb"), forState: .Normal)
  </code></pre>
  
  <p>But it stretches the image.</p>
  
  <p>Is it because of the image I have? How can I implement <code>thumbRectForBounds</code> here?</p>
  
  <p>Please help me.</p>
  
  <p>Thanks in advance.</p>