Unregister all delegates from a EventHandler

EventHandlerHelper.cs

/// <summary>
/// Unregisters all delegates from an EventHandler.
/// </summary>
/// <param name="eventHandler">EventHandler to clear.</param>
public static void UnregisterAllDelegates(ref EventHandler eventHandler)
{
    // Cancel if already cleared.
    if (eventHandler == null)
        return;

    // Clear the EventHandler.
    var invocations = eventHandler.GetInvocationList();
    foreach (var invocation in invocations)
        eventHandler -= invocation as EventHandler;

    // Release the handler.
    eventHandler = null;
}

/// <summary>
/// Unregisters all delegates from an EventHandler.
/// </summary>
/// <param name="eventHandler">EventHandler to clear.</param>
/// <typeparam name="T">Type of EventHandler.</typeparam>
public static void UnregisterAllDelegates<T>(ref EventHandler<T> eventHandler)
{
    // Cancel if already cleared.
    if (eventHandler == null)
        return;

    // Clear the EventHandler.
    var invocations = eventHandler.GetInvocationList();
    foreach (var invocation in invocations)
        eventHandler -= invocation as EventHandler<T>;

    // Release the handler.
    eventHandler = null;
}