Adding a Custom Lookup to a Form Field in Axapta

In Dynamics AX one way you can add a custom lookup or drop down list to a form control by overriding the lookup method of the control.  Below is some example code for doing this.

public void lookup()
{
    SysTableLookup          sysTableLookup =
    SysTableLookup::newParameters(
                            tablenum(CustTable),
                            this);
 
    Query                   query;
    QueryBuildDataSource    queryBuildDataSource;
    ;
 
    sysTableLookup.addLookupfield(
                    fieldnum(CustTable,
                    AccountNum));
    sysTableLookup.addLookupfield(
                    fieldnum(CustTable,
                    Name));
    
 
    query = new Query();
 
    // Add datasource to the query
    queryBuildDataSource = query.addDataSource(
                           tablenum(CustTable));

    queryBuildRange = queryBuildDataSource.addRange(

                      fieldNum(CustTable, AccountNum));
   

    select firstonly AccountNum from custTable;
    queryBuildRange.value(queryRange(custTable.AccountNum, ''));
 
    sysTableLookup.parmQuery(query);
 
    sysTableLookup.performFormLookup();
}

Happy Daxing! :)