dll的调用故障

Question

sdll文件如下:library sdll;
uses
  SysUtils,
  Classes;
  function GetInteger(I:Integer): Integer;stdcall;
  function GetDouble(D:Double): Double;stdcall;
{$R *.res}
  function GetInteger(I:Integer): Integer;stdcall;
  begin
    Result := I;
  end;  function GetDouble(D:Double): Double;stdcall;
  begin
    Result := D;
  end;
exports
  GetInteger,
  GetDouble;
begin
end.调用dll文件:unit usedll1;interfaceuses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,Dialogs, StdCtrls;type
  TForm1 = class(TForm)
    Button1: TButton;
    Edit1: TEdit;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;
  function GetDouble(D:Double): Double;stdcall;external 'sdll.dll';
  function GetInteger(I:Integer): Integer;stdcall;external 'sdll.dll';
var
  Form1: TForm1;implementation{$R *.dfm}procedure TForm1.Button1Click(Sender: TObject);
begin
  edit1.Text := inttostr(GetInteger(100));
end;end.运行后就是报错如下:project f:\delphi\usedll.exe faulted with message:'access violation at ox77f8ea53:write of address ox00030cb4'.process stopped.use step or run to continue.由于是第一次搞DLL,望大家指导指导!多谢了!

Answer 1

library sdll;
uses
  SysUtils,
  Classes;
  //function GetInteger(I:Integer): Integer;stdcall;
  //function GetDouble(D:Double): Double;stdcall;//--------把这两行去掉就行了。^_^
{$R *.res}
  function GetInteger(I:Integer): Integer;stdcall;
  begin
    Result := I;
  end;  function GetDouble(D:Double): Double;stdcall;
  begin
    Result := D;
  end;
exports
  GetInteger,
  GetDouble;
begin
end.

Answer 2

+上 
uses 
 ShareMem;

Answer 3

procedure TForm1.Button2Click(Sender: TObject);
type
TGetDouble=function(D:Double):Integer;stdcall;
var
D: Double;
DLLHandle: THandle;
Func: TGetDouble;
begin
DLLHandle := LoadLibrary('sdll.dll');
try
  @Func := GetProcAddress(DLLHandle, 'GetDouble');
  if Assigned(@Func) then
  begin
    D := Func(2.2);//为什么 D=1073846681?????
    Edit1.Text := FloatToStr(D);
  end;
  finally
    FreeLibrary(DLLHandle);
  end;
end;在动态调用的时候为什么 D=1073846681

Answer 4

因为:
type
  TGetDouble=function(D:Double):Integer;stdcall;
                                ^这里写错了

Answer 5

jadeluo(秀峰):
能说的详细一点吗?那应该怎么写才是对的?多谢了!