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Xamarin Community Toolkit WeakEventManager

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An event implementation that enables the garbage collector to collect an object without needing to unsubscribe event handlers.

Inspired by Xamarin.Forms.WeakEventManager.

Syntax

public WeakEventManager<TEventArgs>()

Methods

Methods Return Type Description
AddEventHandler(EventHandler<TEventArgs>, string eventName) void Adds the event handler.
AddEventHandler(Action<TEventArgs>, string eventName) void Adds the event handler.
RemoveEventHandler(EventHandler<TEventArgs>, string eventName) void Removes the event handler.
RemoveEventHandler(Action<TEventArgs>, string eventName) void Removes the event handler.
HandleEvent(object, TEventArgs, string void Invokes the event EventHandler.
HandleEvent(TEventArgs, string void Invokes the event Action.
RaiseEvent(object, TEventArgs, string void Invokes the event EventHandler.
RaiseEvent(TEventArgs, string void Invokes the event Action.

Examples

This section shows how to use this type.

Use EventHandler<T>

readonly WeakEventManager<string> _errorOcurredEventManager = new WeakEventManager<string>();

public event EventHandler<string> ErrorOcurred
{
    add => _errorOcurredEventManager.AddEventHandler(value);
    remove => _errorOcurredEventManager.RemoveEventHandler(value);
}

void OnErrorOcurred(string message) => _errorOcurredEventManager.RaiseEvent(this, message, nameof(ErrorOcurred));

Use Action<T>

readonly WeakEventManager<string> _weakActionEventManager = new WeakEventManager<string>();

public event Action<string> ActionEvent
{
    add => _weakActionEventManager.AddEventHandler(value);
    remove => _weakActionEventManager.RemoveEventHandler(value);
}

void OnActionEvent(string message) => _weakActionEventManager.RaiseEvent(message, nameof(ActionEvent));

API