title: Sort Group summary in Xaml Infragistics grid
body: <p>I have requirement to sort group summary field.</p>
  
  <p>Ex. I have 3 columns in the grid.</p>
  
  <p>Step 1 : I have group by Id by dragging the Id column in Group by area.</p>
  
  <p>Step 2: Add Sum,Count,Average on column.</p>
  
  <p>Now i want to sort sum or count or average by clicking on that ,so that the whole grouped is sorted by sum like 100,200,300. </p>
  
  <p>please help </p>
  
  <p><img src="https://i.stack.imgur.com/3uYyC.png" alt="enter image description here"></p>