Create a QR code from multiple textboxes and decode it back into the textboxes

Question

I have created an application. This app contains the five textboxes id, name, surname, age and score.

When a user clicks the "okay button", these values are stores in an sql database.

Additionally, I want to store all of these information in an QR code. And when I decode it, the information should be shown in the textboxes respectively.

These are the references I am using so far.

using AForge.Video.DirectShow;
using Zen.Barcode;
using ZXing.QrCode;
using ZXing;

I can encode an ID number into a picture box, like so:

    CodeQrBarcodeDraw qrcode = BarcodeDrawFactory.CodeQr;
    pictureBox1.Image = qrcode.Draw(textBox1.Text, 50);

But I want all of the values in the textboxes to be storee in this QR code.

How can i do that?

Answer 1

The essence of the solution is, that you have to combine all the values from the textboxes into one string. To seperate them after decoding the QR code, you have to add a special character between the data values, that does not exist insinde the user input. After decoding the QR code, you can seperate the values by splitting the string at each occurance of the special character.

---

This is the quick and dirty way of doing that. If you want the QR code to be conformant to any specific format (like vcard), you have to reserach what it takes to compose the data for this format.

I expect your users cannot enter more than one line into the textboxes, so the newline character can be used as seperator character.

Encode all the information into one QR code.

var qrText = textBox1.Text + "\n" + 
    textBox2.Text + "\n" + 
    textBox3.Text + "\n" + 
    textBox4.Text + "\n" + 
    textBox5.Text;

pictureBox1.Image = qrcode.Draw(qrText, 50);

You can decode the QR code and assigning the data to the different textboxes again.

var bitmap = new Bitmap(pictureBox1.Image);
var lumianceSsource = new BitmapLuminanceSource(bitmap);
var binBitmap = new BinaryBitmap(new HybridBinarizer(source));

var reader = new MultiFormatReader();
Result result = null;

try
{
    result = reader.Decode(binBitmap);
}
catch (Exception err)
{
    // Handle the exceptions, in a way that fits to your application.
}

var resultDataArray = result.Text.Split(new char[] {'\n'});

// Only if there were 5 linebreaks to split the result string, it was a valid QR code.
if (resultDataArray.length == 5)
{
    textBox1.Text = resultDataArray[0];
    textBox2.Text = resultDataArray[1];
    textBox3.Text = resultDataArray[2];
    textBox4.Text = resultDataArray[3];
    textBox5.Text = resultDataArray[4];
}