Choosing the right deployment model

We'll talk in more detail about how to deploy distributed applications that are using the Windows App SDK in Chapter 11, Publishing Your Application, but it's critical to introduce at the beginning two important concepts, since they will influence the way you create an application – packaged and unpackaged.

Packaged applications adopt MSIX as a deployment technology. MSIX is the most recent packaging format introduced in Windows, which, compared to other deployment technologies such as MSI or ClickOnce, brings many benefits:

• A cleaner install and uninstall process, thanks to the usage of a lightweight container that virtualizes many of the critical aspects of Windows, such as the filesystem and the registry
• Built-in features such as automatic updates even in unmanaged scenarios (such as a website), bandwidth optimization, and disk space optimization
• Tampering protection, which prevents an app that has been improperly changed from running and damaging an operating system

Windows applications packaged with MSIX are described by a manifest, which is an XML file that holds information such as the name, the publisher, the version number, and the dependencies. The packaged approach is the best one for applications that use the Windows App SDK, since it simplifies many of the scenarios that we're going to see in this book, such as managing the framework dependency and using Windows APIs that require an identity.

However, as a developer, you might face scenarios where a packaged app doesn't fit your requirements:

• The container provided by MSIX is very thin, but there are still situations when it might interfere with the regular execution of your application due to the isolation of the registry and the filesystem.
• To work properly, the application must deploy, during the installation, a kernel driver, or it must apply some global settings to the computer, such as creating environment variables and installing a Windows feature. The isolated nature of MSIX doesn't make these kinds of scenarios a good fit.

Because of these cases, the Windows App SDK also supports unpackaged apps, which are applications that you can deploy the way you prefer by using manual copy deployment, adopting a traditional MSI installer, building a custom setup, or using a script. The way you deploy your application is deeply connected to the way you manage the dependency that your application has with the Windows App SDK. Let's learn more in the next section.