SingleInstance unit

Singleinstance contains the basic abstract definition of a class TBaseSingleInstance that, when instantiated, will make sure only 1 instance of your application will be running. It is an abstract instance, you need to instantiate a descendent such as can be found in the advancedsingleinstance unit.

In this document, the first started instance of an application is called the Server, any application started later is called a Client application.

The single instance functionality also provides a mechanism to communicate parameters from the client to the server. For example, an editor started a second time may wish to pass any filenames to be opened to the server instance.

Classes and records

ESingleInstance	class	Exception raised in case of errors.
TBaseSingleInstance	class	Abstract class for single application instance.

Types

TBaseSingleInstanceClass	type	class of TBaseSingleInstance.
TSingleInstanceParamsEvent	procedure type	Callback type for the TBaseSingleInstance.OnServerReceivedParams event.
TSingleInstanceStart	enumeration	Result type for the call.

Variables

DefaultSingleInstanceClass

variable

Class to instantiate when creating a TBaseSingleInstance instance.

Uses

• SysUtils
• Classes