AX / Dynamics 365 For Finance and Operations blog

In a dialog you cannot use primitive type dialog fields. You must necessarily use extended data types
So how do you use simple string or integer data? Simple, use an extended data type that extends a primitive data type.

DialogField tableDlg;
Dialog dialog = super();

tableDlg = dialog.addField(extendedTypeStr(String255), 'String'); //For string
 
tableDlg = dialog.addField(extendedTypeStr(Integer), 'Integer');  //For Integer

tableDlg = dialog.addField(extendedTypeStr(Integer64), 'Integer64');  //For Integer 64