Application Domains and Services in Visual Basic .NET

Maker QR Code in Visual Basic .NET Application Domains and Services

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3. Which of the following are valid ways to install a service on a computer (Choose all that apply.) A. Add a shortcut to your assembly to the user s Startup group B. Use InstallUtil to install your service C. Configure Scheduled Tasks to start your assembly upon startup D. Use Visual Studio to create an installer for your service 4. Which tools can you use to change the user account for a service after the service is installed A. My Computer B. Computer Management C. The Net command D. NET Framework Configuration tool 5. You need to configure a service so that it runs in the context of a specific user account. Systems administrators already have created the user account and provided you with the username and password. What should you do A. Define the Account, Username, and Password properties of the ServiceProcessInstaller class. B. Define the ServiceInstaller.StartType property. C. In the Services snap-in, set the Startup Type to Manual. D. On the Security tab of the project properties, use the Zone to define the account settings.

To practice and reinforce the skills you learned in this chapter further, you can complete the following tasks: Review the chapter summary. Review the list of key terms introduced in this chapter. Complete the case scenarios. These scenarios set up real-world situations involving the topics of this chapter and ask you to create a solution. Complete the suggested practices. Take a practice test.

Summary

Application domains are logical containers that allow multiple assemblies to run within a single process without being able to access memory belonging to each other directly. Application domains offer separate memory spaces and separate access to resources without the overhead of creating a second process. When you create a new application domain, you can control many aspects of that application domain s configuration. Most importantly, you can restrict the privileges of assemblies running within the application domain by providing evidence when creating the application domain or when starting the process. Services run in the background without providing an interface to the user. Creating a service is different from creating other types of applications because you cannot run a service executable file directly. Instead, you must install the service manually or create a setup project for the service. Other considerations unique to services include start-up type, account type, and management tools.

Do you know what these key terms mean You can check your answers by looking up the terms in the glossary at the end of the book. Application domain Defense-in-depth Evidence

In the following case scenarios, you apply what you ve learned about how to use application domains and services. You can find answers to these questions in the Answers section at the end of this book.

You are a developer for the Baldwin Museum of Science. Your users run your application from various locations. Because the .NET Framework runtime assigns different permission sets based on the assembly s location, your assembly is often running in a partially trusted environment. This situation has caused problems for your users. Your manager asks you to interview key company personnel and to then come to her office to answer some questions. Your manager needs you to create an application that creates an application domain and starts an assembly in the new application domain using Internet zone permissions to enable more realistic testing procedures.

The following is a list of company personnel interviewed and their statements. We re getting a lot of calls from customers who want to deploy our app from a Web server. It seems like this doesn t work for some reason, though. Users end up getting different errors. From the way they describe the errors, it seems like the application crashes at different times depending on whether the application is started from the public Internet or the user s local intranet. Right now we just tell them to copy it to their local computers and run it, and that seems to solve the problem. The IT people don t like this workaround, though, and want to know why we can t make it work from a Web server.

Customer Support Manager Development Manager I talked to the Customer Support Manager, and it sounds

like users are having problems because of code access security restrictions. We need to start testing our application in different zones so that we can identify