C++ 结构到 Delphi Record dll 调用

Question

我正在尝试将 c++ struct 转换为 delphi Record 以进行 dll 调用

// c++ struct

typedef struct dll_info_t
{
   char version[32];
   char r_type[128];
   char b_date[32];
   char c_list[32];
   char build[32];
}dll_info_t;

LIBEX_EXPORT int LIB_API Dll_get_lib_info(dll_info_t* info);

// Delphi Converted

dll_info_t = record
 version:AnsiChar;
 r_type:AnsiChar;
 b_date:AnsiChar;
 c_list:AnsiChar;
 build:AnsiChar;
end;
        
Dll_get_lib_info: Function (info : dll_info_t) : Integer; stdcall;

var
  hHandle:THandle;
begin
  hHandle := LoadLibrary(Dl_path);
    @Dll_get_lib_info:=GetProcAddress(hHandle, PChar('Dll_get_lib_info'));

    if Assigned(Dll_get_lib_info) then begin
     Dll_get_lib_info(info);
     ShowMessage(info.version); // <- I Get Empty Output
     ShowMessage(info.release_type); // <- I Get Empty Output
     ShowMessage(info.build_date); // <- I Get Empty Output
     ShowMessage(info.change_list); // <- I Get Empty Output
    end;

end;

我得到空输出

我不确定转换后的记录是否正确？

我已经在 delphi 中检查了在线 char 是 Ansichar 吗？

Answer 1

char version[32] 与AnsiChar 不同，因为 AnsiChar 是单个字符。您需要一个 AnsiChar 数组 (version: array [0..31] of AnsiChar)，就像在 C 代码中使用的一样。您需要为记录的所有成员正确声明。

type
  dll_info_t = record
    version: array [0..31] of AnsiChar;
    r_type: array [0..127] of AnsiChar;
    b_date: array [0..31] of AnsiChar;
    c_list: array [0..31] of AnsiChar;
    build: array [0..31] of AnsiChar;
  end;

var 
  Dll_get_lib_info: Function(out info: dll_info_t): Integer; stdcall;
  hMod: HMODULE;
  info: dll_info_t;
begin
  hMod := LoadLibrary(Dl_path);
  @Dll_get_lib_info := GetProcAddress(hMod, 'Dll_get_lib_info');

  if Assigned(Dll_get_lib_info) then begin
    Dll_get_lib_info(info);
    ShowMessage(info.version);
    ShowMessage(info.release_type);
    ShowMessage(info.build_date);
    ShowMessage(info.change_list);
  end;
end;

stdcall 是否正确取决于LIB_API 宏的定义。