title: Setting the Scrollbar Thumb size
body: <p>I am attempting to work out the algorithm associated with sizing of the WPF Scrollbar thumb element. </p>
  
  <p>The thumb element can be sized using the <code>Scrollbar.ViewportSize</code> property, but it in turn is related to the <code>Scrollbar.Minimum</code> and <code>Scrollbar.Maximum</code> values. </p>
  
  <p>What I have discovered so far is:</p>
  
  <p>For a Minimum and Maximum of <strong>0</strong> and <strong>10</strong>, a ViewportSize of:</p>
  
  <p>0 - Thumb minimum size<br>
  5 - Thumb approximately 25% of the available track<br>
  10 - Thumb approximately 50% of the available track<br>
  100 - Thumb approximately 75% of the available track<br>
  1000 - Thumb approximately 90% of the available track<br>
  10000 - Thumb fills the available track.</p>
  
  <p>[note: these figures are only from my rough trial and error!]</p>
  
  <p>Ideally I'd like to be able to have an algorithm where given the minimum and maximum values for the Scrollbar I can set the thumb size to be exactly x% of the available track.</p>
  
  <p>Can anyone help with this?</p>
  
  <p>Thanks.</p>