Wpf Managing Application Updates Complete Guide

In this example, I will walk through both ClickOnce and a custom manual update mechanism that checks for updates from a web server.

1. ClickOnce Deployment

ClickOnce is a deployment method provided by .NET Framework that allows users to install and run a WPF application directly from a web page. It automatically handles updates and prompts users to install new versions.

Step 1: Create a WPF Application

1. Open Visual Studio.
2. Create a new WPF App (.NET Framework) project.
3. Name your project WPFCustomUpdateExample.

Step 2: Configure ClickOnce Publishing

1. Right-click on your project in Solution Explorer, and select Publish....
2. In the Publish wizard, click Next and specify your publishing location (e.g., a folder on your local drive, FTP, HTTP, etc.).
3. Click Next again, and configure your installation folder URL. This should point to where the published files are accessible from the web.
4. Click Next, and then on Options.
5. Select the Updates tab and check The application should check for updates.
6. Decide whether to check for updates Before the application starts or After the application is started.
7. Set the Minimum required version to the current version or a past version depending on the updates you want.
8. Save the configuration and publish the application.

Step 3: Deploy and Test the Application

• Copy the published files to the specified folder or upload them to your web server.
• Run the .application file from your browser or directly (if downloaded).
• Visual Studio will create a shortcut on your desktop. You can also find it in the Start menu.
• Modify your application and re-publish with a higher version number.
• Run the application and see if it detects and installs the update.

2. Custom Manual Update Mechanism

For more advanced scenarios, you can create a custom update system that checks for new versions from a web server, downloads the latest installer, and then prompts the user to close the application and run the new installer.

Step 1: Create a WPF Application

• Follow the same steps as in Step 1 of the ClickOnce example to create a new WPF project named WPFCustomUpdateExample.

Step 2: Setup a Web Server to Host the Latest Installer

Assuming you have an updated installer (AppSetup.exe) hosted on a web server at URL https://yourserver.com/AppSetup.exe, you'll write code to download and execute it.

Step 3: Add Version Check Logic

1. Add an XML file to the web server that contains the latest version number of the application:

   <version>2.0</version>
   

2. Modify App.xaml.cs to include code to check for updates:

   using System;
   using System.IO;
   using System.Net;
   using System.Windows;
   
   namespace WPFCustomUpdateExample
   {
       public partial class App : Application
       {
           private const string LatestVersionUrl = "https://yourserver.com/version.xml";
           private const string InstallerUrl = "https://yourserver.com/AppSetup.exe";
   
           protected override void OnStartup(StartupEventArgs e)
           {
               base.OnStartup(e);
   
               if (IsUpdateAvailable())
               {
                   InstallUpdate();
                   Current.Shutdown();
               }
           }
   
           private bool IsUpdateAvailable()
           {
               try
               {
                   using (var wc = new WebClient())
                   {
                       var latestVersionString = wc.DownloadString(LatestVersionUrl);
                       var latestVersion = System.Version.Parse(latestVersionString.Replace("<version>", "").Replace("</version>", ""));
   
                       // Get the current application version from its assembly information
                       var appVersion = System.Reflection.Assembly.GetExecutingAssembly().GetName().Version;
   
                       return appVersion < latestVersion;
                   }
               }
               catch (Exception ex)
               {
                   MessageBox.Show("Error checking for updates: " + ex.Message, "Update Error", MessageBoxButton.OK, MessageBoxImage.Error);
                   return false;
               }
           }
   
           private void InstallUpdate()
           {
               try
               {
                   using (var wc = new WebClient())
                   {
                       var installerFilePath = Path.Combine(Path.GetTempPath(), "AppSetup.exe");
                       wc.DownloadFile(InstallerUrl, installerFilePath);
   
                       MessageBox.Show("A new version is available. Click OK to install.", "Update Available", MessageBoxButton.OK, MessageBoxImage.Information);
                       System.Diagnostics.Process.Start(installerFilePath);
                   }
               }
               catch (Exception ex)
               {
                   MessageBox.Show("Error downloading update: " + ex.Message, "Update Error", MessageBoxButton.OK, MessageBoxImage.Error);
               }
           }
       }
   }
   

3. Explanation of Code:

   • LatestVersionUrl: The URL of the XML file that contains the latest version number.
   • InstallerUrl: The URL of the latest installer executable.
   • OnStartup: Overrides the default startup event. Checks for updates before showing the main window.
   • IsUpdateAvailable: Downloads the version XML file, parses the version, and compares it with the current application version.
   • InstallUpdate: Downloads the installer executable to a temporary path and runs it.

4. Build and Test:

   • Build your application.
   • Manually rename the existing version of your app to something like AppOld.exe.
   • Place the updated version at the web server.
   • Run the old version of your application and test if it correctly identifies the newer version and prompts you to install it.