急着交啊.
c++中声明如下：
typedef  struct T{
    float Re;
    float Im;
}TComplex;

__declspec(dllexport)  void  _stdcall ABCC(TComplex  Source[],TComplex Dest[],int Count);

delphi中声明和调用如下:
procedure ABCC(var Source: array of TComplex; var Dest:array of TComplex;var Count: integer);stdcall;external 'DLL.dll';

  var
  t1,t2:array of TComplex;
  i:integer;
  t:single;
  begin
  GetMem(t1,sizeof(TComplex)*2);
  t:=1.11;
  for i:=0 to 1 do
  begin
    t1[i].Re:=t;
    t:=t+1.11;
    t1[i].Im:=t;
    t:=t+1.11;
  end;
GetMem(t2,sizeof(TComplex)*2);
  i:=2;
  ABCC(t1,t2,i);
  }

  发现进入dll后,第二个参数和第三个参数的值传不进去,只要使用到第二个参数就读写错.
  第一个参数正常,晕死,急着交啊.

DLL的参数不能使用class相关的东西.

delphi 中TComplex声明如下：
 
TComplex = packed record
    Re: float;
    Im: float;
  end;

不好意思 看错了
procedure ABCC(var Source: of TComplex; var Dest:TComplex;Count:integer);stdcall;external 'DLL.dll';

回2楼，用delphi生成的dll，可以这样调用，我现在是把delphi代码改为c++的

多写了一个of
procedure ABCC(var Source:TComplex; var Dest:TComplex;Count:integer);stdcall;external 'DLL.dll';

不好意思复制错了，这三个参数，有两个是动态结构数组；
var Source: array of TComplex; var Dest:array of TComplex;var Count: integer

__declspec(dllexport)  void  _stdcall ABCC(TComplex  Source[],TComplex Dest[],int Count);
前两个参数只TComplex* ,是指向TComplex  类型的指针,
你用var Source:TComplex是可以的
,你也可以传元素的指针进去用source:^TComplex类型的参数.

var Source:TComplex是可以，但要在DLL中访问数组其他元素怎么办？

你传入一个数组的第一个元素,其实传递的也还是一个指针.

dll中自然可以正常访问.

这样改不行，现在是要求我写C的dll,用delphi调，delphi这边的程序不变了

引用 11 楼 smileni 的回复:

这样改不行，现在是要求我写C的dll,用delphi调，delphi这边的程序不变了

要是要求是这样,哪么帮顶一下,俺无能为力

谢！

1.C++导出函数给delphi用要加extern "C"
2.delphi的record传参数入栈时会多放一个结构长
3.delphi的var Count传的是地址
所以你的C++要这样写（我测试一下，通过）
extern "C" __declspec(dllexport)  void  __stdcall ABCC(TComplex  Source[],int,TComplex Dest[],int,int &Count)

14楼的朋友，好像不行啊，能在c++中读出第二个参数结构数组的值吗？

验证后还是不对

忘了结构定义了：
typedef  struct T{
    double Re;
    double Im;
}TComplex; //delphi没有float

我的delphi的定义：
type  TComplex=packed record
Re:real;
Im:real;
end;

procedure ABCC(Source: array of TComplex; Dest:array of TComplex; var Count: integer);stdcall;external 'bcbd.dll';
完整的测试程序：

C/C++ code

//—————————————————————————

#include <windows.h>
//—————————————————————————
//   Important note about DLL memory management when your DLL uses the
//   static version of the RunTime Library:
//
//   If your DLL exports any functions that pass String objects (or structs/
//   classes containing nested Strings) as parameter or function results,
//   you will need to add the library MEMMGR.LIB to both the DLL project and
//   any other projects that use the DLL.  You will also need to use MEMMGR.LIB
//   if any other projects which use the DLL will be performing new or delete
//   operations on any non-TObject-derived classes which are exported from the
//   DLL. Adding MEMMGR.LIB to your project will change the DLL and its calling
//   EXE’s to use the BORLNDMM.DLL as their memory manager.  In these cases,
//   the file BORLNDMM.DLL should be deployed along with your DLL.
//
//   To avoid using BORLNDMM.DLL, pass string information using "char *" or
//   ShortString parameters.
//
//   If your DLL uses the dynamic version of the RTL, you do not need to
//   explicitly add MEMMGR.LIB as this will be done implicitly for you
//—————————————————————————

#pragma argsused
int WINAPI DllEntryPoint(HINSTANCE hinst, unsigned long reason, void* lpReserved)
{
        return 1;
}
typedef  struct T{
    double Re;
    double Im;
}TComplex;
extern "C" __declspec(dllexport)  void  __stdcall ABCC(TComplex  Source[],int,TComplex Dest[],int,int &Count);

extern "C" __declspec(dllexport)  void  __stdcall ABCC(TComplex  Source[],int,TComplex Dest[],int,int &Count)
{
    for (int i=0;i<Count;i++)
    {
       Dest[i].Re=  Source[i].Re;
       Dest[i].Im=  Source[i].Im;
     }
}
//—————————————————————————

Delphi(Pascal) code

unit d1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

type
  TForm1 = class(TForm)
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}
type  TComplex=packed record
 Re:real;
 Im:real;
end;
procedure ABCC(Source: array of TComplex; Dest:array of TComplex; var Count: integer);stdcall;external ‘bcbd.dll‘;

procedure TForm1.Button1Click(Sender: TObject);
  var
  t1,t2:array of TComplex;
  ct:integer;
begin
  ShowMessage(inttostr(sizeof(TComplex)));
  GetMem(t1,sizeof(TComplex)*2);
  GetMem(t2,sizeof(TComplex)*2);
  t1[0].re:=111;
  t1[0].Im:=222;
  t1[1].re:=333;
  t1[1].Im:=444;
  t2[0].re:=555;
  t2[0].Im:=666;
  t2[1].re:=777;
  t2[1].Im:=888;
  ct:=2;
  ABCC(t1,t2,ct);
  ShowMessage(Format(‘%f %f %f %f‘,[t2[0].re,t2[0].im,t2[1].re,t2[1].im]));
end;

end.

非常感谢keiy和akirya ，刚才打电话来说，这个函数用DELPHI自己调，不用我弄了，把我气晕死了，弄这个东西好几天了，不眠不休，我明天结贴给分，今天没有时间了，还要赶，命苦！

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