title: How to implement Multistate CheckBox in WPF for MVVM
body: <p>I have a requirement for which i need a <strong>MultiState Checkboxes</strong> in WPF...</p>
  
  <p>Also as i am using MVVM so handling binding and Commands should follow the same as i will use it in my Views.</p>
  
  <p>I have seen a Multistate checkbox in DotnetNuke(made in ASP.NET) but how to make it in WPF</p>
  
  <p>some inputs in this regards will be helpful</p>
  
  <p>Some example will be great...</p>