public void removeWhere_numElements(int numElementsToRemove)
{
var collection = new MyObservableCollection <int>();
List <int> removedItems = new List <int>();
collection.ItemDetached += (sender, oldItem, index) =>
{
removedItems.Add(oldItem);
};
int maxCount = 30;
collection.AddRange(Enumerable.Range(0, maxCount));
int initCount = collection.Count;
int multiple = 3;
collection.RemoveWhere(val =>
{
int remainder;
int div = Math.DivRem(val, multiple, out remainder);
return(remainder == 0);
}, numElementsToRemove);
Assert.IsTrue(collection.Count == initCount - numElementsToRemove);
var xRemovedItems = Enumerable.Range(0, numElementsToRemove)
.Select(val => val * multiple)
.ToArray();
Assert.AreEqual(removedItems.Count, xRemovedItems.Length);
Assert.IsTrue(!removedItems.Except(xRemovedItems).Any());
Assert.IsTrue(!xRemovedItems.Except(removedItems).Any());
Enumerable.Range(0, maxCount)
.Except(xRemovedItems)
.ForEach(val => Assert.IsTrue(collection.Contains(val)));
xRemovedItems.ForEach(val => Assert.IsFalse(collection.Contains(val)));
}
public void RemoveWhereTest()
{
var collection = new MyObservableCollection <int>();
collection.AddRange(Enumerable.Range(0, 31));
collection.RemoveWhere(val =>
{
int remainder;
int div = Math.DivRem(val, 3, out remainder);
return(remainder == 0);
});
collection.ForEach(val =>
{
int remainder;
int div = Math.DivRem(val, 3, out remainder);
Assert.IsFalse(remainder == 0);
});
}