In Progress-4GL如何将对象设置为接受不同数量的输入？

Question

使用OpenEdge10.2.b ItemObj.cls

CLASS mystuff.ItemObj :
  METHOD PUBLIC CHARACTER GetItemDesc
  ( INPUT pcOne AS CHARACTER,
  INPUT pcTwo AS CHARACTER,
  INPUT piThree   AS INTEGER ) :

    RETURN pcOne pcTwo pcThree.

END METHOD.

ItemObj.p

USING mystuff.*.
DEFINE VARIABLE rItemObj AS CLASS mystuff.ItemObj NO-UNDO.
rItemObj = NEW mystuff.ItemObj( ).
MESSAGE "One : " rItemObj:GetItemDesc (1)       SKIP(1)
        "Two : " rItemObj:GetItemDesc (1, 2)    SKIP(1)
        "Three : " rItemObj:GetItemDesc (1, 2, 3) VIEW-AS ALERT-BOX INFO.
DELETE OBJECT rItemObj.

我希望所有这些语句的输出都是相同的，这样，如果用户只输入1个输入，其他两个默认为2和3，如果用户输入1和2，则3默认为3。

如何在不出现参数不匹配错误的情况下执行此操作？

Answer 1

IIRC Progress不允许在方法定义中使用可选参数，因此您必须为每个参数排列创建一个方法定义，或者接受一个将多个值作为参数处理的数据结构(如动态数组、临时表或自定义对象)，然后将其解包(但这样会将逻辑推送到调用方)。

CLASS mystuff.ItemObj:
  METHOD PUBLIC CHARACTER GetItemDesc (INPUT pcOne   AS CHARACTER,
                                       INPUT pcTwo   AS CHARACTER,
                                       INPUT piThree AS INTEGER):
    RETURN pcOne pcTwo pcThree.
  END METHOD.

  METHOD PUBLIC CHARACTER GetItemDesc (INPUT pcOne   AS CHARACTER,
                                       INPUT pcTwo   AS CHARACTER):
    RETURN GetItemDesc(pcOne, pcTwo, 3).
  END METHOD.

  METHOD PUBLIC CHARACTER GetItemDesc (INPUT pcOne   AS CHARACTER):
    RETURN GetItemDesc(pcOne, "2").
  END METHOD.
END CLASS.