The ServiceInstaller does work specific to the service with which it is associated. It is used by the installation utility to write registry values associated with the service to a subkey within the HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services registry key. The service is identified by its ServiceName within this subkey. The subkey also includes the name of the executable or .dll to which the service belongs.
To install a service, create a project installer class that inherits from the Installer class, and set the RunInstallerAttribute attribute on the class to true. Within your project, create one ServiceProcessInstaller instance per service application, and one ServiceInstaller instance for each service in the application. Within your project installer class constructor, set the installation properties for the service using the ServiceProcessInstaller and ServiceInstaller instances, and add the instances to the Installers collection.
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It is recommended that you use the constructor for adding installer instances; however, if you need to add to the
Installers collection in the Install method, be sure to perform the same additions to the collection in the Uninstall method.
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For all classes deriving from the Installer class, the state of the Installers collection must be the same in the Install and Uninstall methods. However, you can avoid the maintenance of the collection across the Install and Uninstall methods if you add installer instances to the Installers collection in your custom installer class constructor.When the install utility is called, it looks for the RunInstallerAttribute attribute. If the attribute is true, the utility installs all the services that were added to the Installers collection that were associated with your project installer. If RunInstallerAttribute is false or does not exist, the install utility ignores the project installer.
The ServiceProcessInstaller associated with your project installation class installs information common to all ServiceInstaller instances in the project. If this service has anything that separates it from the other services in the installation project, that service-specific information is installed by this method.
You can modify other properties on the ServiceInstaller either before or after adding it to the Installers collection of your project installer. For example, a service's StartType may be set to start the service automatically at reboot or require a user to start the service manually.
Normally, you will not call the methods on ServiceInstaller within your code; they are generally called only by the install utility. The install utility automatically calls the ServiceProcessInstaller..::.Install and ServiceInstaller..::.Install methods during the installation process. It backs out failures, if necessary, by calling Rollback (or ServiceInstaller..::.Rollback) on all previously installed components.
The installation utility calls Uninstall to remove the object.
An application's install routine maintains information automatically about the components already installed, using the project installer's Installer..::.Context. This state information is continuously updated as the ServiceProcessInstaller instance, and each ServiceInstaller instance is installed by the utility. It is usually unnecessary for your code to modify state information explicitly.
When the installation is performed, it automatically creates an EventLogInstaller to install the event log source associated with the ServiceBase derived class. The Log property for this source is set by the ServiceInstaller constructor to the computer's Application log. When you set the ServiceName of the ServiceInstaller (which should be identical to the ServiceBase..::.ServiceName of the service), the Source is automatically set to the same value. In an installation failure, the source's installation is rolled-back along with previously installed services.
The Uninstall method tries to stop the service if it is running. Whether this succeeds or not, Uninstall undoes the changes made by Install. If a new source was created for event logging, the source is deleted.