Deploy ClickOnce applications for testing and production servers without resigning
This article describes a feature of ClickOnce introduced in the .NET Framework version 3.5 that enables the deployment of ClickOnce applications from multiple network locations without re-signing or changing the ClickOnce manifests.
Resigning is still the preferred method for deploying new versions of applications. Whenever possible, use the resigning method. For more information, see Mage.exe (Manifest Generation and Editing Tool).
Third-party developers and ISVs can opt in to this feature, making it easier for their customers to update their applications. This feature can be used in the following situations:
When updating an application, not for the first installation of an application.
When there is only one configuration of the application on a computer. For example, if an application is configured to point to two different databases, you cannot use this feature.
Exclude deploymentProvider from deployment manifests
In the .NET Framework 2.0 and the .NET Framework 3.0, any ClickOnce application that installs on the system for offline availability must list a
deploymentProvider in its deployment manifest. The
deploymentProvider is often referred to as the update location; it is the location where ClickOnce checks for application updates. This requirement, along with the need for application publishers to sign their deployments, made it difficult for a company to update a ClickOnce application from a vendor or other third party. It also makes it more difficult to deploy the same application from multiple locations on the same network.
With changes that were made to ClickOnce in the .NET Framework 3.5, it is possible for a third party to provide a ClickOnce application to another organization, which can then deploy the application on its own network.
In order to take advantage of this feature, developers of ClickOnce applications must exclude
deploymentProvider from their deployment manifests. This requirement means that you must exclude the
-providerUrl argument when you create deployment manifests with Mage.exe. Or, if you are generating deployment manifests with MageUI.exe, you must make sure that the Launch Location text box on the Application Manifest tab is left blank.
deploymentProvider and application updates
Starting with the .NET Framework 3.5, you no longer have to specify a
deploymentProvider in your deployment manifest in order to deploy a ClickOnce application for both online and offline usage. This change supports the scenario where you need to package and sign the deployment yourself, but allow other companies to deploy the application over their networks.
The important point to remember is that applications that exclude a
deploymentProvider cannot change their install location during updates, until they ship an update that includes the
deploymentProvider tag again.
Here are two examples to clarify this point. In the first example, you publish a ClickOnce application that has no
deploymentProvider tag, and you ask users to install it from http://www.adatum.com/MyApplication/. If you decide you want to publish the next update of the application from http://subdomain.adatum.com/MyApplication/, you have no way of signifying this in the deployment manifest that resides in http://www.adatum.com/MyApplication/. You can do one of two things:
Tell your users to uninstall the previous version, and install the new version from the new location.
Include an update on http://www.adatum.com/MyApplication/ that includes a
deploymentProviderpointing to http://www.adatum.com/MyApplication/. Then, release another update later with
deploymentProviderpointing to http://subdomain.adatum.com/MyApplication/.
In the second example, you publish a ClickOnce application that specifies
deploymentProvider, and you then decide to remove it. Once the new version without
deploymentProvideris downloaded to clients, you cannot redirect the path used for updates until you release a version of your application that has
deploymentProviderrestored. As with the first example,
deploymentProvidermust initially point to the current update location, not your new location. In this case, if you attempt to insert a
deploymentProviderthat refers to http://subdomain.adatum.com/MyApplication/, then the next update fails.
Create a deployment
For step by step guidance on creating deployments that can be deployed from different network locations, see Walkthrough: Manually deploy a ClickOnce application that does not require re-signing and that preserves branding information.