delphi调用图形识别dll出错!!!!!!!
delphi 调用图形识别dll总是报地址之类的错误，请大家帮忙看看是什么问题,代码如下:
implementation
function OCR(imgname:string;i:integer):PChar;stdcall;external 'AspriseOCR.dll';
{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
var
vcode:PChar;
filename:string;
begin
filename:='test1.bmp';
vcode:=OCR('e:\poll\demo\test1.bmp',-1);
edit1.Text:=strpas(vcode);
end;

end.

[解决办法]
谁给你做的dll, 第一个参数是 string ?
[解决办法]
初始化pchar
[解决办法]
function OCR(imgname:string;i:integer):PChar;stdcall;external 'AspriseOCR.dll';
改为：
function OCR(imgname:PChar;i:integer):PChar;stdcall;external 'AspriseOCR.dll';
[解决办法]
procedure TForm1.Button1Click(Sender: TObject);
var
vcode: PChar;
s: string;
begin
vcode:= OCR('1.png',-1);
if vCode <> nil then
begin
s := strPas(vcode);
Edit1.Text := s;
end;
end;

[解决办法]