紧急求助关于TIdHTTP在dll中调用问题？

Question

function setjz(url:string;account:string;jz:double):string;export;stdcall;
var
aStream:TStringStream;
sparam:TStrings;
posturl,str1,str2:string;
IdHTTP1:TIdHTTP;
beginastream:=TStringStream.Create('');
sparam:=tstringlist.Create;
 
idhttp1:=tidhttp.Create(nil);
try
str1:='account='+account;
sparam.Add(str1);
str1:='jz='+floattostr(jz);
sparam.add(str1);
posturl:=url+'/send.php';
sparam.Add(str1);
IdHTTP1.Request.ContentType := 'application/x-www-form-urlencoded';
IdHTTP1.Post(posturl, sparam, aStream); //Ìá½»
//str2:=idhttp1.AllData;
str2:=trim(astream.DataString);//»ñÈ¡½á
sparam.Free;
FreeAndNil(idhttp1);
astream.Free;
result:=str2;
except
FreeAndNil(idhttp1);
sparam.Free;
astream.Free;
result:='';
end;
end;代码如上，在程序中调用本函数，第一次调用很正常，第二次调用就报错，调试发现错误出在 
idhttp1:=tidhttp.Create(nil);这一句，我的delphi版本是D7，请大家帮忙解决一下，深表感谢

Answer 1

function getxdhttp(url:string;account:string):string;
var
aStream:TStringStream;
sparam:TStrings;
posturl,str1,str2:string;
IdHTTP1: TIdHTTP;
beginastream:=TStringStream.Create('');
sparam:=tstringlist.Create;
idhttp1:=tidhttp.Create(nil);
idhttp1.HandleRedirects:= true; 
try
str1:='account='+account;
sparam.Add(str1);
posturl:=url+'/get.php';
sparam.Add(str1);
IdHTTP1.Request.ContentType := 'application/x-www-form-urlencoded';
IdHTTP1.Post(posturl, sparam, aStream); //Ìá½»
str2:=trim(astream.DataString);//»ñÈ¡½á
 
finally
sparam.Free;
IdHTTP1.Disconnect;
idhttp1.Free;
//FreeAndNil(idhttp1);
astream.Free;
end;result:=str2;
end;看了网上的文章将程序改成如上，错误依旧，第一可以正常调用，第二次失败

Answer 2

加上判断试试，怀疑没完全释放！if IdHTTP1 = nil then
  idhttp1:=tidhttp.Create(nil); 

Answer 3

楼上的意见，我测试了一下，还是不行，而且每次调试到那里的时候，观察idhttp1的值就是nil，不知道为什么第二次调用这个函数就报错。

Answer 4

调用代码如下，那个dll里面只有两个函数
unit test;interfaceuses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;type
  TForm1 = class(TForm)
    Button1: TButton;
    Button2: TButton;
    Edit1: TEdit;
    Edit2: TEdit;
    Edit3: TEdit;
    Edit4: TEdit;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;var
  Form1: TForm1;function   getxdstr(url:string;account:string):string;stdcall;
far;external 'easer.dll'name 'getxdstr';function setjz(url:string;account:string;jz:double):string;stdcall;
far;external 'easer.dll'name 'setjz';implementation{$R *.dfm}procedure TForm1.Button1Click(Sender: TObject);
begin
edit4.Text:=getxdstr(edit1.text,edit2.text);end;procedure TForm1.Button2Click(Sender: TObject);
begin
setjz(edit1.text,edit2.text,strtofloat(edit3.text));
end;end.

Answer 5

已经搞定了，dll要比写程序麻烦多了，谢谢大家