Debugging and the Hosting Process 

The Visual Studio hosting process improves debugger performance and enables new debugger features, such as partial-trust debugging and design-time expression evaluation. You can disable the hosting process if you need to. For more information, see How to: Disable the Hosting Process. The following sections describe some differences between debugging with and without the hosting process.

Partial-Trust Debugging and Click-Once Security

Partial-trust debugging requires the hosting process. If you disable the hosting process, partial-trust debugging will not work even if partial-trust security is enabled on the Security page of Project Properties. For more information, see How to: Disable the Hosting Process and How to: Debug a Partial Trust Application.

Design-Time Expression Evaluation

Design-time expression always uses the hosting process. Disabling the hosting process in the Project Properties disables design-time expression evaluation for Class Library projects. For other project types, design-time expression evaluation is not disabled. Instead, Visual Studio starts the actual executable and uses it for design-time evaluation without the hosting process. This difference could produce different results.

AppDomain.CurrentDomain.FriendlyName Differences

AppDomain.CurrentDomain.FriendlyName returns different results depending on whether the hosting process is enabled. If you call AppDomain.CurrentDomain.FriendlyName with the hosting process enabled, it returns app_name.vhost.exe. If you call it the hosting process disabled, it returns app_name.exe.

Assembly.GetCallingAssembly().FullName Differences

Assembly.GetCallingAssembly().FullName returns different results depending on whether the hosting process is enabled. If you call Assembly.GetCallingAssembly().FullName with the hosting process enabled, it returns mscorlib. If you call Assembly.GetCallingAssembly().FullName with the hosting process disabled, it returns the application name.

See Also

Tasks

How to: Debug a Partial Trust Application

Concepts

Hosting Process (vshost.exe)
How to: Disable the Hosting Process