Delphi DLL Requires Chilkat v11.7.0+

Generate a QR Code PNG in Memory

See more QR Code Examples

Demonstrates getting a QR code image without writing a file. With no output options the result is a PNG returned as base64 in outputs[0].base64 of the response. The example decodes it into a BinData, which holds the bytes of the PNG to send in an HTTP response, store in a database, attach to an email, or save. Delphi DLL

var
success: Boolean;
json: HCkJsonObject;
fmt: HCkFormats;
jsonOut: HCkJsonObject;
bdPng: HCkBinData;

begin
success := False;

//  This example requires the Chilkat API to have been previously unlocked.
//  See Global Unlock Sample for sample code.

json := CkJsonObject_Create();
CkJsonObject_UpdateString(json,'payload.text','https://www.chilkatsoft.com/');
CkJsonObject_UpdateInt(json,'render.moduleSize',6);

fmt := CkFormats_Create();
jsonOut := CkJsonObject_Create();
success := CkFormats_QrCode(fmt,'generate',json,jsonOut);
if (success = False) then
  begin
    Memo1.Lines.Add(CkFormats__lastErrorText(fmt));
    Exit;
  end;

Memo1.Lines.Add('format: ' + CkJsonObject__stringOf(jsonOut,'outputs[0].format'));
Memo1.Lines.Add('MIME type: ' + CkJsonObject__stringOf(jsonOut,'outputs[0].mimeType'));
Memo1.Lines.Add('image: ' + IntToStr(CkJsonObject_IntOf(jsonOut,'outputs[0].width')) + ' x ' + IntToStr(CkJsonObject_IntOf(jsonOut,'outputs[0].height')) + ' pixels');

//  outputs[0].base64 is the PNG file, base64 encoded.
bdPng := CkBinData_Create();
success := CkBinData_AppendEncoded(bdPng,CkJsonObject__stringOf(jsonOut,'outputs[0].base64'),'base64');
if (success = False) then
  begin
    Memo1.Lines.Add(CkBinData__lastErrorText(bdPng));
    Exit;
  end;
Memo1.Lines.Add('PNG bytes: ' + IntToStr(CkBinData_getNumBytes(bdPng)));

//  The BinData holds the image.  Here it is simply saved.
success := CkBinData_WriteFile(bdPng,'qa_output/qr_in_memory.png');
if (success = False) then
  begin
    Memo1.Lines.Add(CkBinData__lastErrorText(bdPng));
    Exit;
  end;

//  The PNG held in bdPng:

//  

//  Sample output:

//  format: png
//  MIME type: image/png
//  image: 222 x 222 pixels
//  PNG bytes: 877

CkJsonObject_Dispose(json);
CkFormats_Dispose(fmt);
CkJsonObject_Dispose(jsonOut);
CkBinData_Dispose(bdPng);