title: On Button Click validation in WPF
body: <p>I am working on the WPF application. In my application there are different forms which save the data. I want to validation the data on button click or while lost focus from control. I want WPF validations work likes ASP.Net validation.<br><br>
  I do not know the form validate after page load. It should only validate when user lost focus from control or while user click on button.<br><br>
  I have done lot of R&amp;D on google. But I did found any proper setup by setup solution. <br><br>
  Please help me out.</p>