delphi中如何调用DLL,谢谢回复

Question

感谢昨晚的几位的解答,小虾谢了分儿也给了.
http://expert.csdn.net/Expert/topic/1690/1690082.xml?temp=.7899897新问题如下: 
   用VC 写DLL在delphi 中用,原函数如下:   __declspec(dllexport) int _stdcall WriteA(struct cardinfo *cardinfo);
   
  __declspec(dllexport) int _stdcall WriteB(unsigned char *key);  __declspec(dllexport)  int _stdcall OpenCom(int com, long baud);
   
cardinfo 为结构体. 动态连接库为a.dll
   
 大虾们给俺再解答一下吧,分儿继续给!  
 主要是关于参数的如何引用!

Answer 1

我的示例给你看看，不知道对你有什么帮助！！！！
    //声明动态调用的过程
    TGstr = function():Pchar;stdcall;                            //函数的声明
    TMYProc = procedure(var inhandle:HWND; instring:pchar);stdcall;  //是否使用stdcall要依DLL文件决定
                                                                    //注意静态调用时stdcall的位置
    //静态调用动态库
    procedure messageshow( var inhandle:HWND; instring:pchar);stdcall; external 'D:\MyProject\DELPHI\动态库的调用\动态库文件\dllformp.dll';
   function GetString():Pchar;stdcall;external 'D:\MyProject\DELPHI\动态库的调用\动态库文件\dllformp.dll';
   //方法二用name引出
   //procedure messagesho( var inhandle:HWND; instring:pchar);stdcall; external 'D:\MyProject\DELPHI\动态库的调用\动态库文件\dllformp.dll' name 'messageshow';
var
  Form1: TForm1;
  MyLib:THandle;
  i:integer;
implementation{$R *.dfm}procedure TForm1.Button1Click(Sender: TObject);var
    temp:Pchar;
    AHandle:HWND;
begin
     temp:='呵呵，你好啊！';
      AHandle:=application.Handle;
      edit1.Text:=getstring();
      messageshow(AHandle,temp);
      edit1.Text:='';
end;procedure TForm1.Button2Click(Sender: TObject);
var
   temp1:Pchar;
   UHandle:HWND;
   P:TMYproc;
   G:TGstr;
begin
    temp1:='呵呵，你好啊！';
    UHandle:=application.Handle;
    if MyLib>0 then
    begin         @G:=getprocaddress(mylib,'GetString');      //调用入口
         if @G<>nil then
            begin
                 edit1.Text:=G();
            end
         else
            showmessage('没有找到函数的入口');         @p:=GetProcAddress(mylib,'messageshow');
         if @p<>nil then
            begin
                 p(UHandle,temp1);
            end
         else
            showmessage('没有找到函数的入口');         edit1.Text:='';  
    end
    else
         showmessage('函数加载失败！');
end;procedure TForm1.Button3Click(Sender: TObject);
begin
       messagebeep(0);
       TIMER1.Enabled:=TRUE;
end;procedure TForm1.Timer1Timer(Sender: TObject); //加载动态资源，动态库在FORM CREATE 中加载
var
   IconHand:THandle;
begin
      if isiconic(application.Handle) then
         begin
            if i>9 then
               i:=1;            iconhand:=loadicon(mylib,Pchar('ICON'+INTTOSTR(I)));
            if iconhand<> 0 then
               application.Icon.Handle:=iconhand
            else
                showmessage('can''t find icon!');
            inc(i);
         end;     
end;procedure TForm1.FormCreate(Sender: TObject);
begin
        MyLib:=LoadLibrary('D:\MyProject\DELPHI\动态库的调用\动态库文件\dllformp.dll');
      if mylib=0 then
      begin
         showmessage('Can''t Load The Dll!');
         application.Terminate;
      end;
      i:=1;
      
end;procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction);
begin
    freelibrary(mylib);
end;end.

Answer 2

应该是这样：
function WriteA(cardinfo:pointer):Integer; stdcall; external 'a.dll';
function WriteB(key:string):Integer; stdcall; external 'a.dll';
function OpenCom(com:Integer;baud:longint):Integer; stdcall; external 'a.dll';
不一定对，试试看？

Answer 3

应该如下
 type 
   Pcardinfo=^cardinfo;
function WriteA(cardinfo:Pcardinfo):Integer; stdcall; external 'a.dll';
function WriteB(key:PChar):Integer; stdcall; external 'a.dll';
function OpenCom(com:Integer;baud:longint):Integer; stdcall; external 'a.dll';

Answer 4

呵呵！看：
http://expert.csdn.net/Expert/topic/1645/1645329.xml?temp=.5758631

Answer 5

如果结构体是:
struct  cardinfo 
{
  cardid[6];
  cardunit[10];
};
那么在dephi 中结构体如何定义?