Check for application updates programmatically using the ClickOnce deployment API

ClickOnce provides two ways to update an application once it is deployed. In the first method, you can configure the ClickOnce deployment to check automatically for updates at certain intervals. In the second method, you can write code that uses the ApplicationDeployment class to check for updates based on an event, such as a user request.

The following procedures show some code for performing a programmatic update and also describe how to configure your ClickOnce deployment to enable programmatic update checks.

In order to update a ClickOnce application programmatically, you must specify a location for updates. This is sometimes referred to as a deployment provider. For more information on setting this property, see Choose a ClickOnce update strategy.

To check for updates programmatically

1. Create a new Windows Forms application using your preferred command-line or visual tools.

2. Create whatever button, menu item, or other user interface item you want your users to select to check for updates. From that item's event handler, call the following method to check for and install updates.

   • C#
   • VB
   • C++

   private void InstallUpdateSyncWithInfo()
   {
       UpdateCheckInfo info = null;
   
       if (ApplicationDeployment.IsNetworkDeployed)
       {
           ApplicationDeployment ad = ApplicationDeployment.CurrentDeployment;
   
           try
           {
               info = ad.CheckForDetailedUpdate();
   
           }
           catch (DeploymentDownloadException dde)
           {
               MessageBox.Show("The new version of the application cannot be downloaded at this time. \n\nPlease check your network connection, or try again later. Error: " + dde.Message);
               return;
           }
           catch (InvalidDeploymentException ide)
           {
               MessageBox.Show("Cannot check for a new version of the application. The ClickOnce deployment is corrupt. Please redeploy the application and try again. Error: " + ide.Message);
               return;
           }
           catch (InvalidOperationException ioe)
           {
               MessageBox.Show("This application cannot be updated. It is likely not a ClickOnce application. Error: " + ioe.Message);
               return;
           }
   
           if (info.UpdateAvailable)
           {
               Boolean doUpdate = true;
   
               if (!info.IsUpdateRequired)
               {
                   DialogResult dr = MessageBox.Show("An update is available. Would you like to update the application now?", "Update Available", MessageBoxButtons.OKCancel);
                   if (!(DialogResult.OK == dr))
                   {
                       doUpdate = false;
                   }
               }
               else
               {
                   // Display a message that the app MUST reboot. Display the minimum required version.
                   MessageBox.Show("This application has detected a mandatory update from your current " + 
                       "version to version " + info.MinimumRequiredVersion.ToString() + 
                       ". The application will now install the update and restart.", 
                       "Update Available", MessageBoxButtons.OK, 
                       MessageBoxIcon.Information);
               }
   
               if (doUpdate)
               {
                   try
                   {
                       ad.Update();
                       MessageBox.Show("The application has been upgraded, and will now restart.");
                       Application.Restart();
                   }
                   catch (DeploymentDownloadException dde)
                   {
                       MessageBox.Show("Cannot install the latest version of the application. \n\nPlease check your network connection, or try again later. Error: " + dde);
                       return;
                   }
               }
           }
       }
   }
   

3. Compile your application.

Use Mage.exe to deploy an application that checks for updates programmatically

• Follow the instructions for deploying your application using Mage.exe as explained in Walkthrough: Manually deploy a ClickOnce application. When calling Mage.exe to generate the deployment manifest, make sure to use the command-line switch providerUrl, and to specify the URL where ClickOnce should check for updates. If your application will update from http://www.adatum.com/MyApp, for example, your call to generate the deployment manifest might look like this:

  mage -New Deployment -ToFile WindowsFormsApp1.application -Name "My App 1.0" -Version 1.0.0.0 -AppManifest 1.0.0.0\MyApp.manifest -providerUrl http://www.adatum.com/MyApp/MyApp.application
  

Using MageUI.exe to deploy an application that checks for updates programmatically

• Follow the instructions for deploying your application using Mage.exe as explained in Walkthrough: Manually deploy a ClickOnce application. On the Deployment Options tab, set the Start Location field to the application manifest ClickOnce should check for updates. On the Update Options tab, clear the This application should check for updates check box.

.NET Framework Security

Your application must have full-trust permissions to use programmatic updating.

Related content

• How to: Specify an alternate location for deployment updates
• Choose a ClickOnce update strategy
• Publish ClickOnce applications