How to: 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 Choosing a ClickOnce Update Strategy.

Note

You can also use the technique described below to deploy your application from one location but update it from another. For more information, see How to: Specify an Alternate Location for Deployment Updates.

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.

   Private Sub InstallUpdateSyncWithInfo()
       Dim info As UpdateCheckInfo = Nothing 
   
       If (ApplicationDeployment.IsNetworkDeployed) Then 
           Dim AD As ApplicationDeployment = ApplicationDeployment.CurrentDeployment
   
           Try
               info = AD.CheckForDetailedUpdate()
           Catch dde As DeploymentDownloadException
               MessageBox.Show("The new version of the application cannot be downloaded at this time. " + ControlChars.Lf & ControlChars.Lf & "Please check your network connection, or try again later. Error: " + dde.Message)
               Return 
           Catch ioe As InvalidOperationException
               MessageBox.Show("This application cannot be updated. It is likely not a ClickOnce application. Error: " & ioe.Message)
               Return 
           End Try 
   
           If (info.UpdateAvailable) Then 
               Dim doUpdate As Boolean = True 
   
               If (Not info.IsUpdateRequired) Then 
                   Dim dr As DialogResult = MessageBox.Show("An update is available. Would you like to update the application now?", "Update Available", MessageBoxButtons.OKCancel)
                   If (Not System.Windows.Forms.DialogResult.OK = dr) Then
                       doUpdate = False 
                   End If 
               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)
               End If 
   
               If (doUpdate) Then 
                   Try
                       AD.Update()
                       MessageBox.Show("The application has been upgraded, and will now restart.")
                       Application.Restart()
                   Catch dde As DeploymentDownloadException
                       MessageBox.Show("Cannot install the latest version of the application. " & ControlChars.Lf & ControlChars.Lf & "Please check your network connection, or try again later.")
                       Return 
                   End Try 
               End If 
           End If 
           End If 
   End Sub
   

   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;
                   }
               }
           }
       }
   }
   

   public:
       void InstallUpdateSync()
       {
           if (ApplicationDeployment::IsNetworkDeployed)
           {
               bool isUpdateAvailable = false;
               ApplicationDeployment^ appDeployment =
                   ApplicationDeployment::CurrentDeployment;
   
               try
               {
                   isUpdateAvailable = appDeployment->CheckForUpdate();
               }
               catch (InvalidOperationException^ ex)
               {
                   MessageBox::Show("The update check failed. Error: {0}",
                       ex->Message);
                   return;
               }
   
               if (isUpdateAvailable)
               {
                   try
                   {
                       appDeployment->Update();
                       MessageBox::Show(
                           "The application has been upgraded, and will now " +
                           "restart.");
                       Application::Restart();
                   }
                   catch (Exception^ ex)
                   {
                       MessageBox::Show("The update failed. Error: {0}",
                           ex->Message);
                       return;
                   }
   
               }
           }
       }
   

3. Compile your application.

Using 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 Deploying 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 Deploying 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.

Security

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

See Also

Tasks

How to: Specify an Alternate Location for Deployment Updates

Concepts

Choosing a ClickOnce Update Strategy

Publishing ClickOnce Applications