title: How to Disable the Parent Form When a Child Form is Active Within MDI Parent Form?
body: <p><img src="https://i.stack.imgur.com/SkVWz.png" alt="How to Disable the Parent Form When a Child Form is Active and Within MDI Parent Form?"></p>
  
  <p>'Add Product' is a child of MDI Parent Form, and 'Add Category' is child of 'Add Product' form. I already bind 'Add Category' to MDI Parent Form by using following code</p>
  
  <pre><code>        frm_Add_Category obj_AddCategory = new frm_Add_Category();
          obj_AddCategory.MdiParent = this.MdiParent;
          obj_AddCategory.Show();
  </code></pre>
  
  <p>Now it is not going out of the border of MDI Parent Form. Next what I have to do is make 'Add Product' disable when 'Add Category' form pop up. I look through all over the web but when I fix this 'Add Category' is going out to the MDI Parent Form. I already tried all methods which explained <a href="https://stackoverflow.com/questions/1130208/how-to-disable-the-parent-form-when-a-child-form-is-active">here</a>.</p>
  
  <p>As a summery what I want to do is</p>
  
  <ol>
  <li>'Add Category' Cannot go out from the MDI Parent Form.</li>
  <li>'Add Product' should disable/un-clickable when 'Add Category' pops.</li>
  <li>'Add Product' should enable/clickable when 'Add Category' closed.</li>
  </ol>