Question

I am getting an error in my delphi code when using shellexecute to call an external progrem

procedure TReceiverMainForm.btnSearchClick(Sender: TObject);
 var
  args:string;
begin
  mmoResult.Clear;
//  args := ' /d='  + TIdURI.URLEncode(Trim(sSearch)) + ' /t=ReceiverMainForm /s=30 /m=1'
args := ' /q='  + httpencode(Trim(txtSearch.Text)) + ' /t=ReceiverMainForm /s='+Trim(txtS.Text)+' /m='+Trim(txtM.Text);
  ShellExecute(Handle, 'open', 'YTD.exe', pWideChar(args), nil, SW_SHOWNORMAL);
end;

how do i reslve this error?

Answer 1

The ShellExecute function is defined like so

function ShellExecute(hWnd: HWND; Operation, FileName, Parameters,
  Directory: PChar; ShowCmd: Integer): HINST; stdcall;

So the issue is which you are casting the args variable to a PWideChar instead of a PChar.

Try this code

ShellExecute(Handle, 'open', 'YTD.exe', PChar(args), nil, SW_SHOWNORMAL);

Remember that Delphi 7 pre-dates the Unicode Delphi development. And so PChar is an alias for the 8 bit character type, PAnsiChar.