IGrouping<TKey,TElement>.Key Eigenschaft

Definition

Namespace:

System.Linq

Assemblys:

netstandard.dll, System.Linq.dll

Quelle:

Grouping.cs

Ruft den Schlüssel der IGrouping<TKey,TElement>.

public:
 property TKey Key { TKey get(); };

public TKey Key { get; }

member this.Key : 'Key

Public ReadOnly Property Key As TKey

Eigenschaftswert

TKey

Der Schlüssel des IGrouping<TKey,TElement>.

Beispiele

Im folgenden Beispiel wird veranschaulicht, wie Key die Eigenschaft verwendet wird, um jedes IGrouping<TKey,TElement> Objekt in einer Abfolge von IGrouping<TKey,TElement> Objekten zu bezeichnen. Die GroupBy<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>) Methode wird verwendet, um eine Abfolge von IGrouping<TKey,TElement> Objekten abzurufen. The foreach in Visual C# or For Each in Visual Basic loop then iterates through each IGrouping<TKey,TElement> object, outputting its key and the number of values it contains.

// Get a sequence of IGrouping objects.
IEnumerable<IGrouping<System.Reflection.MemberTypes, System.Reflection.MemberInfo>> memberQuery =
    typeof(String).GetMembers().
    GroupBy(member => member.MemberType);

// Output the key of each IGrouping object and the count of values.
foreach (IGrouping<System.Reflection.MemberTypes, System.Reflection.MemberInfo> group in memberQuery)
    Console.WriteLine("(Key) {0} (Member count) {1}", group.Key, group.Count());

// The output is similar to:
// (Key) Method (Member count) 113
// (Key) Constructor (Member count) 8
// (Key) Property (Member count) 2
// (Key) Field (Member count) 1

' Get a sequence of IGrouping objects.
Dim memberQuery As  _
IEnumerable(Of IGrouping(Of System.Reflection.MemberTypes, System.Reflection.MemberInfo)) = _
    Type.GetType("String").GetMembers(). _
    GroupBy(Function(ByVal member) member.MemberType)

' Output the key of each IGrouping object and the count of values.
For Each group As  _
IGrouping(Of System.Reflection.MemberTypes, System.Reflection.MemberInfo) In memberQuery
    MsgBox(String.Format("(Key) {0} (Member count) {1}", group.Key, group.Count()))
Next

' The output is similar to:
' (Key) Method (Member count) 113
' (Key) Constructor (Member count) 8
' (Key) Property (Member count) 2
' (Key) Field (Member count) 1

Hinweise

Der Schlüssel eines IGrouping<TKey,TElement> Elements stellt das Attribut dar, das für jeden Wert in der IGrouping<TKey,TElement>.