怎么样使用系统提供功能模块Function Module？

1. 将负号放到数字的前面：CLOI_PUT_SIGN_IN_FRONT
   说明：Move the negative sign from the left hand side of a number, to the right hand side
   of the number. Note that The result will be left justified (like all character
   fields), not right justifed as numbers normally are.
2. 转换日期格式：SLS_MISC_CONVERT_TO_DATE
   说明：
   CALL FUNCTION 'SLS_MISC_CONVERT_TO_DATE'
   EXPORTING
   p_date = sy-datum
   P_DATE_FORMAT
   = 'YYYY-MM-DD'
   IMPORTING
   P_DATE_STRING = G_DATE_STRING
   EXCEPTIONS
   ERROR_SELECTING_USER_DEFAULTS = 1
   OTHERS = 2
   .

3. 读取用户地址：SUSR_USER_ADDRESS_READ
   说明：
   CALL FUNCTION 'SUSR_USER_ADDRESS_READ'
   EXPORTING
   USER_NAME = SY-UNAME
   READ_DB_DIRECTLY = ' '
   IMPORTING
   USER_ADDRESS = ADDR3_VAL
   USER_USR03 = USR03
   EXCEPTIONS
   USER_ADDRESS_NOT_FOUND = 1
   OTHERS = 2.
   IF SY-SUBRC = 0.

4. 读取用户Email地址：ADDR_PERS_COMP_COMM_GET
   说明：
   CALL FUNCTION 'ADDR_PERS_COMP_COMM_GET'
   EXPORTING
   ADDRESS_NUMBER = ADDR3_VAL-ADDRNUMBER
   LANGUAGE = SY-LANGU
   PERSON_NUMBER = ADDR3_VAL-PERSNUMBER
   TABLE_TYPE = 'ADSMTP'
   TABLES
   COMM_TABLE = IN_EMAIL
   EXCEPTIONS
   OTHERS = 1.

5. 读取domain（域）描述：DOMAIN_VALUE_GET
   说明：
   CALL FUNCTION 'DOMAIN_VALUE_GET'
   EXPORTING
   I_DOMNAME =
   I_DOMVALUE =
   * IMPORTING
   * E_DDTEXT =
   * EXCEPTIONS
   * NOT_EXIST = 1
   * OTHERS = 2

6. 选择上传文件时，弹出文件浏览界面：F4_FILENAME
   说明：
   CALL FUNCTION 'F4_FILENAME'
   * EXPORTING
   * PROGRAM_NAME = SYST-CPROG
   * DYNPRO_NUMBER = SYST-DYNNR
   * FIELD_NAME = ' '
   * IMPORTING
   * FILE_NAME =

7. 上载文件是否存在检查：WS_QUERY
   说明：
   CALL FUNCTION 'WS_QUERY'
   EXPORTING
   FILENAME = P_FILE
   QUERY = 'FE'
   IMPORTING
   RETURN = G_FLAG_RCODE
   EXCEPTIONS
   INV_QUERY = 01
   NO_BATCH = 02.
   
   IF G_FLAG_RCODE = '0'. " 文件不存在，给出相关提示信息。
   MESSAGE '您选择的文件不存在,请重新选择上载文件?' TYPE 'I'.
   EXIT.
   ENDIF.

8. 将Excel表格的内容读入内表：ALSM_EXCEL_TO_INTERNAL_TABLE
   说明：
   CALL FUNCTION 'ALSM_EXCEL_TO_INTERNAL_TABLE'
   EXPORTING
   FILENAME = P_FILE
   I_BEGIN_COL = G_COLUMN_BEGIN "从第1列读取
   I_BEGIN_ROW = G_ROW_BEGIN "从第2行读取
   I_END_COL = G_COLUMN_COUNT "共9列
   I_END_ROW = '65536'
   TABLES
   INTERN = TAB_INTERN.
   * EXCEPTIONS
   * INCONSISTENT_PARAMETERS = 1
   * UPLOAD_OLE = 2
   * OTHERS = 3
   
   IF SY-SUBRC <> 0.
   MESSAGE '您上传的文件是合法的EXCEL文件吗?' TYPE 'S'.
   ENDIF.

9. 将金额转换为大写：ZFUN0001（应该是顾问开发的，今天又用到一次，收藏过来：）
   说明：
   CALL FUNCTION 'ZFUN0001'
   EXPORTING
   l_val = REC_MAINDATA-RMWWR
   IMPORTING
   l_word = G_UPPER.
   
   代码见另外一篇帖子：

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