如何在模块Project1.exe中修复'访问冲突，地址为00660938。 读取地址00000150。” 在印第（Delphi 10.3 Rio）

Question

I'm am writing a software which will decrypt JDownloader DLC files. This program will send the dlc file to " http://dcrypt.it/decrypt/upload " with POST request and will get decoded links as response.

This is my code which throws that error:

var
  Form1: TForm1;
    Stream: TStringStream;
    Params: TIdMultiPartFormDataStream;
    HTTP: TIdHTTP;

implementation

{$R *.dfm}

procedure TForm1.Button2Click(Sender: TObject);
begin
  Stream := TStringStream.Create('');
  Params := TIdMultiPartFormDataStream.Create;
  Params.AddFile('File1', 'D:\3fcaa401f8f3ebe32fb93cb607ecadd01ee954ed.dlc', 'application/octet-stream');
  HTTP.Post('http://dcrypt.it/decrypt/upload', Params, Stream);
  ShowMessage(Stream.DataString);
end;

When I debug my program, Delphi IDE shows these in IdHTTP.pas:

function TIdCustomHTTP.GetRequest: TIdHTTPRequest;
begin
 Result := FHTTPProto.Request; //This line is highlighted.
end;

So, what should I do in order to fix this issue?

Answer 1

You are not initializing the HTTP component. Since it is a global variable it will be automatically initialized to nil .

When you call HTTP.Post('http://dcrypt.it/decrypt/upload', Params, Stream); it will not break immediately at the place of call. You are calling it on a nil reference, so it causes the AV as soon as it accesses some inner field or attempts to call a virtual method.

You have to construct the HTTP component before you use it:

HTTP := TIdHTTP.Create(nil);
try
  ...
finally
  HTTP.Free;
end;

---

Also, good practice is that you should avoid using global variables. You can and should declare all the necessary variables as local. And make sure that you release everything after you are done.