Visual Basic 2010 : Deploying Applications with ClickOnce - Configuring ClickOnce

You can customize your ClickOnce deployment by setting its property page in My Project. Click the Publish tab to activate the ClickOnce options designer represented in Figure 1.

Figure 1. The ClickOnce properties designer enables customizing the deployment.

Notice that the upper part of the designer shows properties that you already set with the Publish Wizard. The Publish Version group enables specifying the deployment version that is important for allowing automatic updates. Automatically incrementing the revision number is a convenient way for allowing installed applications to check for updates. Just remember that the publish version is just a ClickOnce-related version and does not affect the application version. Now let’s take a look at the other available options.

Application Files

By clicking the Application Files button, you can view or specify files that need to be included in the deployment package. If you want some required files included in the deployment package (such as documents or databases), you need to set their Build Action property as Content. Generally Visual Studio can automatically classify files according to their role in the project, so this is something that you rarely need to perform manually.

Prerequisites

Prerequisites are those files that the application needs to work correctly, for example runtime components such as the .NET Framework or third-party controls, which the installer installs on the target machine before the application is installed. Generally Visual Studio can detect the appropriate prerequisites and select them for you, but there are situations in which you need to perform this manually, for example when you need to install third-party components. Figure 2 shows the Prerequisites dialog.

Figure 2. Selecting prerequisites for your applications.

If you use third-party components, ensure that the producer made available a redistributable package that you can include in the deployment prerequisites. The .NET Framework will always be included as a prerequisite, because ClickOnce cannot predict if on the target machine the .NET Framework is already available.

Custom Prerequisites

Visual Studio 2010 does not provide a built-in functionality for packaging custom prerequisites. To accomplish this particular need, follow the instructions described in this page of the MSDN Library: http://msdn.microsoft.com/en-us/library/ms165429(VS.100).aspx. An alternative is using a free tool called Boostrapper Manifest Generator, which is available on the MSDN Code Gallery. At the time of this writing, the tool is only available for Visual Studio 2008, so periodically check its workspace for updates at http://code.msdn.microsoft.com/bmg.

Updates

One of the most important features in ClickOnce (and one of the reasons why you should use it) is the capability of updating applications without writing code to accomplish this. The idea is that you publish a new version of the application and when you run the old version, this checks for updates and automatically upgrades to the new version. Notice that automatic updates are not available for applications published to the file system. To enable automatic updates, click the Updates button and then in the Application Updates dialog, check The Application Should Check for Updates check box, as shown in Figure 3.

Figure 3. Enabling automatic updates.

For example, you can decide if the application will be updated before it starts (default option) so that users always run the latest updates or if it will be updated after it starts, but in this case changes will be applied only at the next start. You can also specify how frequently the application has to check for updates. The default setting is that the application checks for updates each time it runs; otherwise, you can specify a time interval expressed in days or hours or minutes. (This option is available only if you decide to update the application after it starts.)

Options

Additions introduced to ClickOnce by the .NET Framework 3.5 SP 1 have been reprised in .NET Framework 4.0 to provide better installation customization. When you click the Options button, you have access to additional features. For example, you can edit the Description part in the deployment manifest so that you can set a full description for your installation. Figure 4 shows an example of how you can specify information.

Figure 4. Setting description options for the deployment package.

Consider that the Publisher name will be utilized to create a root shortcuts folder in the Start menu, whereas the Suite name value will be utilized to create a shortcuts subfolder for the current application. The Deployment option enables setting some aspects of the publish process. Figure 5 shows an example for setting such options.

Figure 5. Setting deployment options.

For example, you can decide if the Publish.htm web page has to be created and shown, if the wizard generates an Autorun.inf file for automatic CD start, or if the deployment will use the .deploy extension. Pay attention to this particular option. Unless you uncheck this check box, the application files will be deployed with the addition of the .deploy extension, which may cause errors if your application attempts to access external files. If this is your case, disable the extension and deploy the application again. The Manifest option enables establishing how application URLs must be treated, but more particularly it enables setting if a desktop shortcut needs to be created for your application (see Figure 6).

Figure 6. Setting manifest options.

Another useful option is the File Associations that is basically the only Registry customization allowed to ClickOnce and that enables assigning a file extension to your executable.