public void UndoService_Uses_WeakReferences()
{
// Create a root, but don't keep any references to the object that it is for.
UndoRoot undoRoot = null;
WeakReference wrDoc = GetWeakReference(out undoRoot);
// Confirm the object is still alive.
Assert.IsNotNull(undoRoot);
Assert.IsTrue(wrDoc.IsAlive);
// Force a GC to collect the document used for the undo root.
// Don't do this in normal code... this is just for testing.
GC.Collect(1, GCCollectionMode.Forced, true);
// Confirm the RootDocument was collected.
// This shows that we're not leaking memory via the UndoService's _Roots dictionary.
Assert.IsFalse(wrDoc.IsAlive);
Assert.IsNull(wrDoc.Target);
// Inline function.
// This method is part of UndoService_Uses_WeakReferences.
// Code is in a separate method so that the variables are properly scoped
// which allows the GC call to work properly.
WeakReference GetWeakReference(out UndoRoot undoRoot)
{
var document = new RootDocument(); // Constructed, but not returned.
undoRoot = UndoService.Current[document]; // This creates a weakly referenced undo root.
return(new WeakReference(document)); // Return a weak reference so that we can test if the document was collected.
}
}
public void TestSetup()
{
Document1 = new RootDocument();
Document1.A = new ChildA()
{
Name = "Document1.ChildA", UndoableSometimes = "Value1"
};
Document1.Bs.Add(new ChildB()
{
Name = "Document1.ChildB[0]"
});
Document1.Bs.Add(new ChildB()
{
Name = "Document1.ChildB[1]"
});
Document1.Bs.Add(new ChildB()
{
Name = "Document1.ChildB[2]"
});
Document1.KeyValuePairs[0] = new ChildA()
{
Name = "Document1.ChildA.0"
};
Document1.KeyValuePairs[1] = new ChildA()
{
Name = "Document1.ChildA.1"
};
Document1.KeyValuePairs[2] = new ChildA()
{
Name = "Document1.ChildA.2"
};
Assert.IsNotNull(Document1.A.Root);
Assert.AreSame(Document1, Document1.A.Root);
Assert.AreSame(Document1, Document1.Bs[0].Root);
Assert.AreSame(Document1, Document1.Bs[1].Root);
Assert.AreSame(Document1, Document1.Bs[2].Root);
Document2 = new RootDocument();
Document2.A = new ChildA()
{
Name = "Document2.ChildA", UndoableSometimes = "Value2"
};
Document2.Bs.Add(new ChildB()
{
Name = "Document2.ChildB[0]"
});
Document2.Bs.Add(new ChildB()
{
Name = "Document2.ChildB[1]"
});
Document2.Bs.Add(new ChildB()
{
Name = "Document2.ChildB[2]"
});
UndoService.Current.Clear();
}