Idea is to build a URL, make an HTTP request and download the QR Code image. Result is the following image:

HTTP Request

URL looks like http://www.esponce.com/api/v3/generate?content={content}&format={format} where {content} is URL encoded content to be embedded in QR and {format} is output image format. Available formats are png, jpg, bmp, tif, xaml, svg, eps, txt, html, zip (containing all listed formats)

List of other parameters like color and size can be found here.

C# Sample

This code can be used in .NET 2.0 including ASP.NET and WPF or Silverlight for web or WP7

using System;
using System.IO;
using System.Web;
using System.Net;

public class Program
{
  public static void Main(string[] args)
  {
    //Generate a QR Code and save it to file "sample.png"
    Generate("your content goes here", "png", "sample.png");
  }

  public static void Generate(string content, string format, string path)
  {
    string encoded = HttpUtility.UrlEncode(content);
    Uri uri = new Uri("http://www.esponce.com/api/v3/generate?content=" + encoded + "&format=" + format);
    WebClient client = new WebClient();
    client.DownloadFile(uri, path);
  }
}

Java Sample

This code can be used in a classic Java application or web applet or Android application

import java.io.*;
import java.net.*;

public class qrcode
{
  public static void main(String args[])
  {
    //Generate a QR Code image and save it to file "sample.png"
    generate("your content goes here", "png", "sample.png");
  }

  public static void generate(String content, String format, String path)
  {
    try
    {
      String encoded = URLEncoder.encode(content, "UTF-8");
      String url = "http://www.esponce.com/api/v3/generate?content=" + encoded + "&format=" + format;
      BufferedInputStream ins = new BufferedInputStream(new URL(url).openStream());
      FileOutputStream fos = new FileOutputStream(path);
      BufferedOutputStream bos = new BufferedOutputStream(fos, 1024);

      int size = 0;
      byte data[] = new byte[1024];
      while ((size = ins.read(data, 0, 1024)) > 0)
      {
        bos.write(data, 0, size);
      }

      bos.close();
      fos.close();
      ins.close();
    }
    catch (Exception e)
    {
    }
  }
}

Python Sample

Using Python 2.7

#!/usr/bin/env python
# -*- coding: UTF-8 -*-

import urllib
import httplib

def generate(content, format = "png"):
    query = urllib.urlencode({ "content": content, "format": format })
    con = httplib.HTTPConnection("www.esponce.com")
    con.request("GET", "/api/v3/generate?" + query)
    response = con.getresponse()
    image = response.read()
    con.close()
    return image

image = generate("your content goes here")
file = open("sample.png", "wb")
file.write(image)
file.close()

JavaScript Sample

JavaScript in combination with HTML

<img id="qrcode" src="" alt="QR Code" />
<script type="text/javascript">
    function generate(content)
    {
        var url = "http://www.esponce.com/api/v3/generate?content=" + encodeURI(content) + "&format=png";
        var img = document.getElementById("qrcode");
        img.src = url;
    }
    generate("your content goes here");
</script>

PHP Sample

<img src="<?php echo generate("your content goes here"); ?>" alt="QR Code" />

<?php
function generate($content, $format = "png")
{
    $encoded = urlencode($content);
    $url = "http://www.esponce.com/api/v3/generate?content=$encoded&format=$format";
    return $url;
}
?>

There is more

Download all samples with make script here.

Other QR Code related methods like decoding (reverse process of generating) and tracking scans can be found at esponce.com.

Lately our team decided to build a simple application for Android phone to try the platform. Story begins with an idea and motivation, installing and setting Eclipse + Android SDK, and like always, a sketch, todo list, etc.

Issues

• For each property in layout xml the “android:” namespace is needed. Of course it can be replace with “a” but it still annoying to write it every time. Example <LinearLayout android:id=”@+id/pnlSomething” />   There is more advanced graphical xml standard – SVG
• oops, I tried (miss-clicked) to run android as classic Java application but it returns an error (like build error),
  next time I try running as android application this error wont go away even if the code is fine
  solution: delete error from the error list and it should work fine
• sometimes I run a debug and don’t notice the tiny icon in the far right bottom corner of eclipse
  that shows the application is launching and it’s stuck… and I try to launch it again, and again
  and applications are trying to launch parallel… solution: close eclipse and start again
• connection refused on localhost? is this a joke? is only google.com allowed?
  firefox opens it normally, firewall is off, same on IIS and apache, permissions are set in manifest.xml
  reason: ‘localhost’ means the internal loopback of device (emulator) not the PC,
  solution: use your LAN IP
  //solution: edit hosts and set something like 127.0.0.1   pc-localhost //does not work
  http://groups.google.com/group/android-developers/browse_thread/thread/801645febf0523ea/9e779925e9570828
• when a crash occurs it is just a crash, without detailed message or tip, developer should guess the error
  * and, BTW, emulator shows wrong time on windows (7:04 PM while the real time is 21:04 on GMT+1 timezone
  or 5:07 PM when the time is 19:07)
• Record breaker among IDEs: 1.131 GB of RAM taken by Eclipse
• A lot of features: social media, web, google maps, sqlite, bluetooth,
• gestures, camera, speech recognition, 3D, processing…
• s it easy to learn? theory yes, it is logical and quite simple, well documented;
  but dealing with basic practical issues is a pain

What really annoys us is that when we write layout in xml and we are confidant with it schema is right, works in theory, draws a preview but just don’t work in emulator Eclipse won’t tell what is the problem it just says “Source Not Found.”

Comparison: C# vs Java

A good programming language uses less code and effort to complete a task. What makes Silverlight (C#) coding easier and Android (Java) coding harder? Advantages of C# over Java or what is missing in Java:

• lambda expression and Linq make handling data, arrays, xml easy
• properties
• partial types when dealing with large files
• preprocessor directives (#if, #region) to bring visual focus on the particular part of code that is being developed and hide the other code
• verbatim string, like @”C:\Program Files\android\sdk.exe” without escape characters
• nullable types, like int? that can be -n…0, 1, 2…n or null
• ‘yield’ keyword
• ‘??’ operator
• enumerations that are avoided in Android (Android uses constants, requires documentation to locate a constant)

* comparing to Silverlight you need to write more code in a more complex way for same features (ie. async, binding,
db, events)

MIDlet-Description: Your application
MIDlet-Icon: /res/p1/icon.png
MIDlet-Jar-Size: 273904
MIDlet-Jar-URL: http://someurl.com/application.jar
MIDlet-Name: AppName
MIDlet-Vendor: VendorName
MIDlet-Version: 0.9.33
MicroEdition-Configuration: CLDC-1.1
MicroEdition-Profile: MIDP-2.0

Be careful and check if you have some empty lines in your JAD file because this is causing this error!
Just delete empty lines.