Dart Requires Chilkat v11.7.0+

QR Code Numeric, Alphanumeric and Byte Modes

See more QR Code Examples

Demonstrates the QR encoding modes. Digits alone are stored in numeric mode, and text made only of digits, upper-case letters, space and $ % * + - . / : in alphanumeric mode. Both pack more characters into a symbol than byte mode, which is used for everything else. QrCode chooses the most compact mode the text allows, and the response reports it. A product code written in upper case therefore gives a smaller symbol than the same code in lower case. Dart

import 'package:chilkat/chilkat.dart';

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

  final fmt = CkFormats();
  final json = CkJsonObject();
  final jsonOut = CkJsonObject();

  // Digits only.
  json.updateString('payload.text', '00123456789012345678');
  try {
    fmt.qrCode('generate', json, jsonOut);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  print('digits: mode ${jsonOut.stringOf('symbols[0].selectedEncoding.mode')}, version ${jsonOut.intOf('symbols[0].selectedEncoding.version')}');

  // Upper-case letters, digits, space and - are all in the alphanumeric set.
  json.updateString('payload.text', 'ORDER-12345 LOT A7 SHELF 12-C');
  try {
    fmt.qrCode('generate', json, jsonOut);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  print('upper case: mode ${jsonOut.stringOf('symbols[0].selectedEncoding.mode')}, version ${jsonOut.intOf('symbols[0].selectedEncoding.version')}');

  // Lower-case letters are not, so the same text in lower case needs byte mode.
  json.updateString('payload.text', 'order-12345 lot a7 shelf 12-c');
  try {
    fmt.qrCode('generate', json, jsonOut);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  print('lower case: mode ${jsonOut.stringOf('symbols[0].selectedEncoding.mode')}, version ${jsonOut.intOf('symbols[0].selectedEncoding.version')}');

  // The mode can be named.  Byte mode can hold any text.  Naming a mode the text cannot use
  // (numeric for text with letters, for example) fails with conflictingOptions.
  json.updateString('payload.text', '00123456789012345678');
  json.updateString('encoding.qr.mode', 'byte');
  try {
    fmt.qrCode('generate', json, jsonOut);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  print('digits as bytes: mode ${jsonOut.stringOf('symbols[0].selectedEncoding.mode')}, version ${jsonOut.intOf('symbols[0].selectedEncoding.version')}');

  // The four symbols, in the order they were made:

  // 

  // Sample output:

  // digits: mode numeric, version 1
  // upper case: mode alphanumeric, version 2
  // lower case: mode byte, version 3
  // digits as bytes: mode byte, version 2
}