First, you create the hook, then subscribe to its events, and then run it. The Run method runs the hook on the current thread, blocking it. The RunAsync() method runs the hook on a separate thread and returns a Task which is finished when the hook is destroyed. You can subscribe to events after the hook is started.

IGlobalHook extends IDisposable. When you call the Dispose method on a hook, it's destroyed. The contract of the interface is that once a hook has been destroyed, it cannot be started again - you'll have to create a new instance.

Important: Always use one instance of IGlobalHook at a time in the entire application since they all must use the same static method to set the hook callback for libuiohook, and there may only be one callback at a time.

SharpHook provides two implementations of IGlobalHook:

• SimpleGlobalHook runs all of its event handlers on the same thread where the hook itself runs. This means that the handlers should generally be fast since they will block the hook from handling the events that follow if they run for too long.

• TaskPoolGlobalHook runs all of its event handlers on other threads inside the default thread pool for tasks. The parallelism level of the handlers can be configured. On backpressure it will queue the remaining handlers. This means that the hook will be able to process all events. This implementation should be preferred to SimpleGlobalHook except for very simple use-cases. But it has a downside - suppressing event propagation will be ignored since event handlers are run on other threads.

The library also provides the GlobalHookBase class which you can extend to create your own implementation of the global hook. It runs the hook on a separate thread and calls appropriate event handlers. You only need to implement a strategy for dispatching the events.

Reactive Global Hooks

Use the SharpHook.Reactive package for reactive global hooks.

Event Simulation

SharpHook provides the ability to simulate keyboard and mouse events in a cross-platform way as well. Here's a quick example:

SharpHook provides the IEventSimulator interface, and the default implementation, EventSimulator, which calls UioHook.PostEvent to simulate the events.

Important: libuiohook ignores modifier masks on Windows, so you need to simulate pressing/releasing modifier keys manually.

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