SAP面向?qū)ο蟮拈_(kāi)發(fā)技術(shù)

1、1SAP面向?qū)ο蟮拈_(kāi)發(fā)技術(shù)面向?qū)ο竽Ｊ?類、屬性和方法3SAP中的類主要由屬性和方法組成：屬性 屬性用于一個(gè)實(shí)例化對(duì)象中保存具體的數(shù)據(jù)?？煞譃楣矊傩院退接袑傩?。方法 方法是類中預(yù)定義的程序處理過(guò)程，可改變類中所有屬性的值。方法同樣分為公共方法和私有方法。CLASS lcl_vehicle DEFINITION. PUBLIC SECTION. DATA: g_model TYPE string. PRIVATE SECTION. DATA: l_model TYPE string.ENDCLASS.方法的參數(shù)4IMPORTING 傳入?yún)?shù)。EXPORTING 傳出參數(shù)。CHANGING 變更

2、參數(shù)。RETURN 返回參數(shù)。不能同時(shí)定義EXPORTING和CHANGING參數(shù)。EXCEPTION 同函數(shù)一樣，方法可以拋出異常，中斷程序。方法的實(shí)現(xiàn)5實(shí)例方法與靜態(tài)方法6類的實(shí)例化7方法的調(diào)用8SAP中類的方法調(diào)用有兩種方式：CALL METHOD ref-method_nameEXPORTING im_par = va_expIMPORTING ex_par = val_impCHANGING ch_par = val_chgRECEIVING re_par = val_recEXCEPTIONS exception = val_rc.ref-method_name(EXPORTING

3、 im_par = va_expIMPORTING ex_par = val_impCHANGING ch_par = val_chgRECEIVING re_par = val_recEXCEPTIONS exception = val_rc ).靜態(tài)方法的調(diào)用9CALL METHOD class_name=method_nameEXPORTING im_par = va_expIMPORTING ex_par = val_impCHANGING ch_par = val_chgRECEIVING re_par = val_recEXCEPTIONS exception = val_rc.c

4、lass_name=method_name(EXPORTING im_par = va_expIMPORTING ex_par = val_impCHANGING ch_par = val_chgRECEIVING re_par = val_recEXCEPTIONS exception = val_rc ).繼承與接口10同其他語(yǔ)言一樣，ABAP中的類也有繼承與接口。繼承 只能繼承一個(gè)父類。CLASS lcl_truck DEFINITION INHERITING FROM lcl_cehicle.PUBLIC SECTION.METHODS estimate_fuel REDEFINITI

5、ON.“ 父類中的聲明必須保留ENDCLASS.CLASS lcl_truck IMPLEMENTATION.METHOD estimate_fuel.super-estimate_fuel()ENDMETHOD.ENDCLASS.繼承與接口11接口 接口類不能被實(shí)例化，不包含方法的實(shí)現(xiàn)。一個(gè)類可以實(shí)現(xiàn)多個(gè)接口類。INTERFACE lif_partner.METHODS display_partner.ENDINTERFACE.CLASS lcl_rental DEFINITION.PUBLIC SECTION.INTERFACES lif_partner.ENDCLASS.CLASS lcl_rental IMPLEMENTAT