DLL Call funktioniert nicht

unit Unit1;


interface


uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, ExtDlgs, OleCtrls, SHDocVw, URLMon, ExtCtrls, jpeg,
  pngimage, ShellApi;


const
  DLL = '..\LibImgUpp.dll';


type
  TImageShackUpload = function (FileName, UserAgent: PWideChar): PWideChar; stdcall;
  TAbout            = function (): PWideChar; stdcall;


type
  TForm1 = class(TForm)
    Label1: TLabel;
    Edit1: TEdit;
    Button1: TButton;
    Embed: TEdit;
    Button2: TButton;
    Button3: TButton;
    OpenDialog1: TOpenDialog;
    Thumb: TEdit;
    Label2: TLabel;
    Label3: TLabel;
    Image1: TImage;
    Bevel1: TBevel;
    Label4: TLabel;
    Label5: TLabel;
    labelX: TLabel;
    Label6: TLabel;
    Direct: TEdit;
    procedure Image1Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;


var
  Form1: TForm1;


implementation


{$R *.dfm}


function GetParameter(Msg: String; Index: Integer; const Separador: String = ','): String;
// by Prodigy_-       #DelphiX
var
  S: String;
  I: Integer;
begin
  if Index > 0 then
  begin
    I := 1;
    S := Msg + Separador;
    while I < Index do
    begin
      S := Copy(S, Pos(Separador,S) + Length(Separador), Length(S));
      Inc(I);
    end;
    S := S + Separador;
    Result := Copy(S, 1, Pos(Separador,S) - 1);
  end;
end;


procedure TForm1.Button1Click(Sender: TObject);
begin
  if OpenDialog1.Execute then
    Edit1.Text := OpenDialog1.FileName;
end;


function TamanhoDoArquivo(FileName: String): Integer;
begin
  with TFileStream.Create(FileName, fmOpenRead or fmShareExclusive) do
  try
    Result := Size div 1024;
  finally
    Free;
  end;
end;


procedure TForm1.Button2Click(Sender: TObject);
var
  Hnd: THandle;
  Img: TImageShackUpload;
  Resultado: String;
  ImagemEmbed: String;
  function PegarExtensao(URL: String): String;
  begin
    Result := Copy(URL, Length(URL) - 3, 4);
    if (Length(Result) > 2) and
       (Result[1] = '.') then
      Delete(Result, 1, 1);
  end;
begin
  if Edit1.Text = '' then
    Exit;
  if TamanhoDoArquivo(Edit1.Text) > 5000 then
    raise Exception.Create('The file must be less than 5 MBytes');
  Hnd := 0;
  if not FileExists(DLL) then
    raise Exception.Create('ImageShack Library not found!');
  try
    Hnd := LoadLibrary(DLL);


    @Img := GetProcAddress(Hnd, 'ImageShackPost');
    if @Img = nil then
      raise Exception.Create('Entrypoint Download not found');


    Edit1.Enabled := False;
    Embed.Clear;
    Direct.Clear;
    Thumb.Clear;
    Image1.Picture := nil;
    Button2.Caption := 'Uploading...';
    Button2.Enabled := False;


    Resultado := string(Img(PWideChar(Edit1.Text), PWideChar('Default')));
    if Resultado = 'file' then
      raise Exception.Create('File Not Found');
    if Resultado = 'send' then
      raise Exception.Create('Error while uploading');
    if Resultado = 'read' then
      raise Exception.Create('Error to get result link');


    Embed.Text := GetParameter(Resultado, 1);
    Thumb.Text := GetParameter(Resultado, 2);
    Direct.Text := GetParameter(Resultado, 3);
    Application.ProcessMessages;
    Edit1.Enabled := True;
    Button2.Caption := 'Upload';
    Button2.Enabled := True;


    { Try load thumb image }
    ImagemEmbed := ExtractFilePath(ParamStr(0)) + 'TMPimg.' + PegarExtensao(Thumb.Text);
    if FileExists(ImagemEmbed) then
      DeleteFile(ImagemEmbed);
    URLDownloadToFile(nil, PWideChar(WideString(Thumb.Text)),
      PWideChar(WideString(ImagemEmbed)), 0, nil);
    if FileExists(ImagemEmbed) then
    try
      Image1.Picture.LoadFromFile(ImagemEmbed);
      labelX.Hide;
    except
    end;
  finally
    FreeLibrary( Hnd );
  end;
end;


procedure TForm1.Button3Click(Sender: TObject);
var
  Hnd: THandle;
  About: TAbout;
  Resultado: String;
begin
  Hnd := 0;
  try
    Hnd := LoadLibrary(DLL);
    if Hnd = HINSTANCE_ERROR then
      raise Exception.Create('Error loading library');


    @About := GetProcAddress(Hnd, 'About');
    Resultado := string(About);
    ShowMessage(Resultado);
  finally
    FreeLibrary( hnd );
  end;
end;


procedure TForm1.Image1Click(Sender: TObject);
begin
  if Direct.Text <> '' then
    ShellExecute(0, nil, PWideChar(Direct.Text), nil, nil, SW_NORMAL);
end;


end.