How to validate dialog fields without closing the dialog window?

I would like to validate the DialogField value without closing the dialog window (not in closeOK). I'm using Dynamics 365 FFO.

class myClassCaller
{
    MyClassDialog::MyPromtDialog(`parameters`);
}


class MyClassDialog 
{
  static container MyPromtDialog(`parameters`)
  {
    DialogField    myDialogField;
    Dialog         dialog;

   ..........

   myDialogField = dialog.addField(extendedtypestr(MYEDT),"Label","Label");

  **// I would like to check/validate the DialogField value**

   if (! dialog.run())
   return ['', ''];

   .....
   return localContainer;
}

There is any way to intercept the value insert in to myDialogField?

Yes, you need to look at registerOverrideMethod.

You can see an example here - https://daxonline.org/1559-simple-dialog-with-field-validation-and-control-override-method.html

You would do something like

myDialogField.registerOverrideMethod(methodStr(FormStringControl, validate), methodStr(YourClass, yourValidateMethod), this);

where this is the object where yourValidateMethod exists.

Then you create a method similar to:

public boolean yourValidateMethod(FormControl _formControl)
{
    ...
}