title: In WPF, How to display validation error in TextBox like the image below?
body: <p>I have a TextBox bound to some property. I have implemented IDataErrorInfo for performing validation. Recently I was seeing some control in web which shows an error like a red triangle. 
  I have attached the sample below:</p>
  
  <p><img src="https://i.stack.imgur.com/Mlczu.jpg" alt="enter image description here"></p>
  
  <p>I know I have to write error template to display this whenever an error occurs. When the user hovers the red triangle, it will display the error message in ToolTip. How do I display an error textBox like the one I have uploaded. How to get the red triangle in error template?</p>