As we known, in AR/AP module->Purch/Sales Line Button->Inventory->Onhand button.

in Invent module->On hand button

When you click this button, you can get quantity information on hand of an item.

When you created a new form included one or more item. How can i implement the function above? or How can get its quantity on hand?

 

Try it:

 

MenuFunction mf = new MenuFunction(menuItemDisplayStr(InventOnHandItem), MenuItemType::Display);

Args args = new Args();

super();

args.caller(element);

args.record(InventTable::find(Table1.Field1));  //Your datesource.itemid

mf.run(args);