title: Modifying a custom UISlider
body: <p>So I have a custom UISlider that I made with the following code:</p>
  
  <pre><code>UIImage *minImage = [UIImage imageNamed:@"settings_slider_fill.png"];
  UIImage *maxImage = [UIImage imageNamed:@"settings_slider_empty.png"];
  UIImage *tumbImage= [UIImage imageNamed:@"settings_slider_handle.png"];
  minImage=[minImage stretchableImageWithLeftCapWidth:10.0 topCapHeight:0.0];
  maxImage=[maxImage stretchableImageWithLeftCapWidth:10.0 topCapHeight:0.0];
  
  [thresholdSlider setMinimumTrackImage:minImage forState:UIControlStateNormal];
  
  [thresholdSlider setMaximumTrackImage:maxImage forState:UIControlStateNormal];
  
  [thresholdSlider setThumbImage:tumbImage forState:UIControlStateNormal];
  </code></pre>
  
  <p>However this gives me a slider with an ugly square end on the left end.  I have an image that I want to use for the left cap, but I don't know how to programmatically set it as such.</p>
  
  <p>This is the left end cap image I want to use:
  <img src="https://i.stack.imgur.com/c5Ex9.png" alt="enter image description here"></p>
  
  <p>This is the fill image I am using:
  <img src="https://i.stack.imgur.com/Odr5U.png" alt="enter image description here"></p>