Generate a QR Code Using C# and a Third-Party Service on Button Click

Use Case

Apart from using the built-in QR code attribute, you can generate a QR code using C# and a third-party service on a button click. You might want to do this to generate a special barcode or customize the QR code: change its size, color, image format or correction level, ad a logo overlay, etc.

In this article, we will configure a button to generate a 300x300px QR code pointing to https://cmwlab.com via the api.qrserver.com service.

Prerequisites

To proceed with the example, create the attributes as shown in the table below:

Instructions

1. In the QRcodeImage attribute properties, check the Auto calculate box and enter the following Calculated value:

   FORMAT("<img align='center' src='data:image/png;base64,{0}'</img>",LIST($QRinBase64))

2. In the QRCodes template, create a button with the following properties:
   • Display name — Generate QR code
   • Operation — C# script
   • Operation context — Record
   • Operation result — Refresh data

   On the Script tab, enter the following script:

   using System;
   using System.Collections.Generic;
   using System.Linq;
   using Comindware.Data.Entity;
   using Comindware.TeamNetwork.Api.Data.UserCommands; 
   using Comindware.TeamNetwork.Api.Data;
   using RestSharp;
   
   class Script  
   {  
         public static UserCommandResult Main(UserCommandContext userCommandContext, Comindware.Entities entities)  
         {  
             ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;  
             byte[] AsBytes = new 
             System.Net.WebClient().DownloadData 
             ("https://api.qrserver.com/v1/create-qr-code/?size=300x300&data=https://cmwlab.com" + userCommandContext.ObjectIds[0]); 
   // 300x300 is desired QR code size
   // https://cmwlab.com is the URL to open upon scanning the QR-code 
             string AsBase64String = Convert.ToBase64String(AsBytes);  
             var data = new Dictionary<string, object> 
             { 
                  { "QRinBase64", AsBase64String } 
   // QRinBase64 is the system name of the attribute to store the QR code in base64 format  
              };  
              Api.TeamNetwork.ObjectService.EditWithAlias("QRCodes", userCommandContext.ObjectIds[0], data); 
   // QRCodes is the system name of the record template where the button is located  
         var result = new UserCommandResult 
         {  
           Success = true,  
           Commited = true,  
           Messages = new[]  
           {  
             new UserCommandMessage  
             {  
               Severity = SeverityLevel.Normal,  
               Text = "QR code was generated" 
   // "QR code was generated" is the success message displayed upon generating the QR code  
             }  
            }  
         };  
     return result;  
       }
   }
   

3. In the QRCodes template, place the QRcodeImage attribute on a form.
4. Place the Generate QR code button on the form's toolbar.
5. Save the form.
6. Open or create a record in the QRCodes template.
7. Click the Generate QR code button: you should see the generated QR code on the form.