public static void Remove()
{
var strings = new WeakRefCollection <string>();
strings.Add("a");
Assert.True(strings.Remove("a"));
Assert.False(strings.Remove("a"));
// comparer parameter is actually used
strings.Add("b");
Assert.True(strings.Remove("B", StringComparer.OrdinalIgnoreCase));
}
public static void Add()
{
var collection = new WeakRefCollection <int[]>();
var array = new int[0];
collection.Add(new WeakReference <int[]>(array));
collection.Add(array); // can store multiple weak references to the same object
Assert.Throws <ArgumentNullException>(() => collection.Add((WeakReference <int[]>)null));
Assert.Throws <ArgumentNullException>(() => collection.Add((int[])null));
}
/// <summary>
/// Enqueues <see cref="UnhandledExceptionEvent"/> for unhandled exceptions thrown on the specified <see cref="Dispatcher"/>.
/// </summary>
/// <param name="dispatcher">The dispatcher to catch unhandled exceptions from, or <c>null</c> for the UI dispatcher.</param>
/// <param name="raiseEvents"><c>true</c> to make sure unhandled exceptions are enqueued; <c>false</c> to make sure they are not.</param>
public static void RaiseUnhandledExceptionEventsFromDispatcher(Dispatcher dispatcher = null, bool raiseEvents = true)
{
if (dispatcher.NullReference())
{
dispatcher = Application.Current?.Dispatcher;
if (dispatcher.NullReference())
{
throw new InvalidOperationException("Could not determine UI dispatcher! (Application.Current is not available)");
}
}
lock ( dispatchersRaisingUnhandledEvents )
{
if (raiseEvents)
{
if (!dispatchersRaisingUnhandledEvents.Contains(dispatcher))
{
dispatchersRaisingUnhandledEvents.Add(dispatcher);
dispatcher.UnhandledException += OnDispatcherUnhandledException;
}
}
else
{
if (dispatchersRaisingUnhandledEvents.Remove(dispatcher))
{
dispatcher.UnhandledException -= OnDispatcherUnhandledException;
}
}
}
}
public static void Contains()
{
var strings = new WeakRefCollection <string>();
strings.Add("a");
// comparer is used as expected
Assert.True(strings.Contains("a", StringComparer.Ordinal));
Assert.False(strings.Contains("A", StringComparer.Ordinal));
Assert.True(strings.Contains("A", StringComparer.OrdinalIgnoreCase));
// null check
Assert.False(strings.Contains(null)); // obvious, since you can't add null
// default comparer (EqualityComparer<T>.Default)
var collection = new WeakRefCollection <AlwaysEqual>();
var item1 = new AlwaysEqual();
var item2 = new AlwaysEqual();
collection.Add(item1);
Assert.True(collection.Contains(item1));
Assert.True(collection.Contains(item2));
Assert.True(collection.Contains(item1, ReferenceEqualityComparer <AlwaysEqual> .Default));
Assert.False(collection.Contains(item2, ReferenceEqualityComparer <AlwaysEqual> .Default));
}
internal static void AddDeviceContext(DeviceContext dc)
{
if (activeDeviceContexts == null)
{
activeDeviceContexts = new WeakRefCollection
{
RefCheckThreshold = 20
};
}
if (!activeDeviceContexts.Contains(dc))
{
dc.Disposing += new EventHandler(OnDcDisposing);
activeDeviceContexts.Add(dc);
}
}