MoreLinq
ExceptBy<(Of <(<'TSource, TKey>)>)> Method (first, second, keySelector)
NamespacesMoreLinqMoreEnumerableExceptBy<(Of <<'(TSource, TKey>)>>)(IEnumerable<(Of <<'(TSource>)>>), IEnumerable<(Of <<'(TSource>)>>), Func<(Of <<'(TSource, TKey>)>>))
Returns the set of elements in the first sequence which aren't in the second sequence, according to a given key selector.
Declaration Syntax
C#Visual BasicVisual C++
public static IEnumerable<TSource> ExceptBy<TSource, TKey>(
	this IEnumerable<TSource> first,
	IEnumerable<TSource> second,
	Func<TSource, TKey> keySelector
)
<ExtensionAttribute> _
Public Shared Function ExceptBy(Of TSource, TKey) ( _
	first As IEnumerable(Of TSource), _
	second As IEnumerable(Of TSource), _
	keySelector As Func(Of TSource, TKey) _
) As IEnumerable(Of TSource)
public:
[ExtensionAttribute]
generic<typename TSource, typename TKey>
static IEnumerable<TSource>^ ExceptBy(
	IEnumerable<TSource>^ first, 
	IEnumerable<TSource>^ second, 
	Func<TSource, TKey>^ keySelector
)
Generic Template Parameters
TSource
The type of the elements in the input sequences.
TKey
The type of the key returned by keySelector.
Parameters
first (IEnumerable<(Of <(<'TSource>)>)>)
The sequence of potentially included elements.
second (IEnumerable<(Of <(<'TSource>)>)>)
The sequence of elements whose keys may prevent elements in first from being returned.
keySelector (Func<(Of <(<'TSource, TKey>)>)>)
The mapping from source element to key.
Return Value
A sequence of elements from first whose key was not also a key for any element in second.
Usage Note
In Visual Basic and C#, you can call this method as an instance method on any object of type IEnumerable<(Of <(<'TSource>)>)>. When you use instance method syntax to call this method, omit the first parameter.
Remarks
This is a set operation; if multiple elements in first have equal keys, only the first such element is returned. This operator uses deferred execution and streams the results, although a set of keys from second is immediately selected and retained.

Assembly: MoreLinq (Module: MoreLinq.dll) Version: 1.0.16006.0 (1.0.16006.1845)