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前言

在Form的字段的onLookUp方法中，添加下拉框。

一、复制onLookUp事件方法

二、LookUp方法

[FormControlEventHandler(formControlStr(EcoResProductDetailsExtended, VyaKeyItemType_VyaMaterialSubCode), FormControlEventType::Lookup)]public static void VyaKeyItemType_VyaMaterialSubCode_OnLookup(FormControl sender, FormControlEventArgs e){FormControlCancelableSuperEventArgs ce  = e as FormControlCancelableSuperEventArgs;FormRun formRun =  sender.formRun();FormStringControl vyaMaterialCodeCtrl = formRun.design().controlName(formControlStr(EcoResProductDetailsExtended, VyaKeyItemType_VyaMaterialCode));str vyaMaterialCodeStr = vyaMaterialCodeCtrl.text();Query                   query           = new Query();QueryBuildDataSource    qbds;QueryBuildRange         qbr;SysTableLookup          sysTableLookup  = SysTableLookup::newParameters(tableNum(VyaMaterialsSubCategories), sender);sysTableLookup.addLookupfield(fieldNum(VyaMaterialsSubCategories, VyaCode));sysTableLookup.addLookupfield(fieldNum(VyaMaterialsSubCategories, VyaDescription));qbds = query.addDatasource(tablenum(VyaMaterialsSubCategories));qbr = qbds.addRange(fieldNum(VyaMaterialsSubCategories,VyaParentMaterial));qbr.value(queryValue(vyaMaterialCodeStr));sysTableLookup.parmQuery(query);sysTableLookup.performFormLookup();ce.CancelSuperCall();}