函数：自定义汇率转换函数

调用：PERFORM frm_get_rate USING u_t-pswsl 'RMB' l_date1
                           CHANGING l_wrbtr.

函数定义：

1：FORM frm_get_rate  USING  u_fc   TYPE bapi1093_1-from_curr
                          u_tc   TYPE bapi1093_1-from_curr
                          u_date TYPE bapi1093_2-trans_date
                   CHANGING c_tot TYPE  bapibp_bal_amt2.
  DATA: l_return TYPE bapiret1,
        l_msg(100) TYPE c.
  CALL FUNCTION 'Z_EXCHANGERATE_CONVERSION'
    EXPORTING
      rate_type  = 'M'
      from_curr  = u_fc
      to_currncy = u_tc
      date       = u_date
    IMPORTING
      return     = l_return
    CHANGING
      amount     = c_tot.

* 汇率获取失败的信息提示
  IF l_return IS NOT INITIAL.
    CONCATENATE u_date u_fc
    '<->' u_tc '的汇率不存在'
    INTO l_msg.
    MESSAGE e000(z03) WITH l_msg.
  ENDIF.

ENDFORM.                    " FRM_GET_RATE

2：FUNCTION Z_EXCHANGERATE_CONVERSION.
*"----------------------------------------------------------------------
*"*"Local interface:
*"  IMPORTING
*"     VALUE(RATE_TYPE) TYPE  BAPI1093_1-RATE_TYPE DEFAULT 'M'
*"     VALUE(FROM_CURR) TYPE  BAPI1093_1-FROM_CURR
*"     VALUE(TO_CURRNCY) TYPE  BAPI1093_1-TO_CURRNCY
*"     VALUE(DATE) TYPE  BAPI1093_2-TRANS_DATE DEFAULT SY-DATUM
*"  EXPORTING
*"     VALUE(RETURN) TYPE  BAPIRET1
*"  CHANGING
*"     VALUE(AMOUNT) TYPE  BAPIBP_BAL_AMT2
*"----------------------------------------------------------------------
  DATA: V_CHAR_E TYPE C VALUE 'E',
        V_CHAR_A TYPE C VALUE 'A'.

  DATA: EXCH_RATE LIKE BAPI1093_0.

** Clear output parameters
  CLEAR: EXCH_RATE,
         RETURN.

  CHECK FROM_CURR <> TO_CURRNCY.

  CALL FUNCTION 'BAPI_EXCHANGERATE_GETDETAIL'
    EXPORTING
      RATE_TYPE  = RATE_TYPE
      FROM_CURR  = FROM_CURR
      TO_CURRNCY = TO_CURRNCY
      DATE       = DATE
    IMPORTING
      EXCH_RATE  = EXCH_RATE
      RETURN     = RETURN.

  IF RETURN IS NOT INITIAL.

    CLEAR: EXCH_RATE,
           RETURN.

    CALL FUNCTION 'BAPI_EXCHANGERATE_GETDETAIL'
      EXPORTING
        RATE_TYPE  = RATE_TYPE
        FROM_CURR  = TO_CURRNCY
        TO_CURRNCY = FROM_CURR
        DATE       = DATE
      IMPORTING
        EXCH_RATE  = EXCH_RATE
        RETURN     = RETURN.

    IF RETURN IS NOT INITIAL.
**     Error, don't get the exchange rate
**     and error information had been saved into parameter RETURN
    ELSE.
**    success to get indirect exchange rate
      IF EXCH_RATE-TO_FACTOR = 0.
        EXCH_RATE-TO_FACTOR = 1.
      ENDIF.
      IF EXCH_RATE-EXCH_RATE = 0.
        EXCH_RATE-EXCH_RATE = 1.
      ENDIF.

      AMOUNT = AMOUNT / EXCH_RATE-EXCH_RATE * EXCH_RATE-FROM_FACTOR
                                            / EXCH_RATE-TO_FACTOR.

    ENDIF.
  ELSE.
**  success to get direct exchange rate
    IF EXCH_RATE-FROM_FACTOR = 0.
      EXCH_RATE-FROM_FACTOR = 1.
    ENDIF.

    AMOUNT = AMOUNT * EXCH_RATE-EXCH_RATE * EXCH_RATE-TO_FACTOR
                                          / EXCH_RATE-FROM_FACTOR.
  ENDIF.

ENDFUNCTION.