title: What are differences between FormControl and FormBuildControl in ax
body: <p>While I was working on the enabling and disabling the form controls I noticed that there are two kinds of form elements. One is the object of the form control class which is accessible as below:</p>
  
  <blockquote>
    <p>FormControl _control  = _formRun.design().controlNum(i)</p>
  </blockquote>
  
  <p>The other type of the form's elements having "build" word which is accessible as follow:</p>
  
  <blockquote>
    <p>FormBuildControl _controlBuild  =
    _formRun.form().design().controlNum(i)</p>
  </blockquote>
  
  <p>Could you please explain what are the differences and when should we use formControl class and when should we use FormBuildControl?</p>
  
  <p>ps: I discover that I cannot enable or editable a field or button using FormBuildControl.</p>