ABAP 怎样将上传文件转化为XSTRING

在 ABAP 中，可以通过使用 CL_GUI_FRONTEND_SERVICES 类的句柄实例方法来选择文件并将其转换为 XSTRING。以下是示例代码：

REPORT demo_upload_file_to_xstring.

PARAMETERS p_file TYPE rlgrap-filename.

DATA: lo_gui_frontend TYPE REF TO cl_gui_frontend_services,
      lv_filetype TYPE string,
      lv_encoding TYPE string,
      lv_xstring TYPE xstring.

lo_gui_frontend = cl_gui_frontend_services=>get_instance( ).
CALL METHOD lo_gui_frontend->gui_upload
  EXPORTING
    filename            = p_file
    filetype            = lv_filetype
    has_field_separator = abap_false
    i_tabname           = ''
    i_callback_program  = sy-repid
  IMPORTING
    filelength          = lv_filesize
    encoding            = lv_encoding
  CHANGING
    data_tab            = lt_data.

* Convert the file data to xstring
CALL FUNCTION 'SCMS_BINARY_TO_XSTRING'
  EXPORTING
    input_length = lv_filesize
  IMPORTING
    buffer       = lv_xstring
  TABLES
    binary_tab   = lt_data.

WRITE: 'The file ', p_file, ' has been uploaded and converted to xstring successfully.'.

在上面的 ABAP 代码中，我们首先使用 `cl_gui_frontend_services=>get_instance( )` 方法获取 CL_GUI_FRONTEND_SERVICES 类的实例。然后，我们使用 `gui_upload` 方法选择上传文件并将文件内容存储在 `lt_data` 表中。最后，我们使用 `SCMS_BINARY_TO_XSTRING` 函数将 `lt_data` 表中的二进制数据转换为 XSTRING 类型的数据。