Assembly : mscorlib (dans mscorlib.dll)
SyntaxePublic Function Contains ( _ item As T _ ) As Boolean
Dim instance As List(Of T) Dim item As T Dim returnValue As Boolean returnValue = instance.Contains(item)
public bool Contains ( T item )
public: virtual bool Contains ( T item ) sealed
public final boolean Contains (
T item
)
public final function Contains ( item : T ) : boolean
Paramètres
- item
Objet à trouver dans List. La valeur peut être référence Null (Nothing en Visual Basic) pour les types référence.
Valeur de retour
true si item existe dans List ; sinon, false.
NotesCette méthode détermine l'égalité à l'aide du comparateur d'égalité par défaut EqualityComparer.Default pour T, le type de valeurs dans la liste.
Cette méthode effectue une recherche linéaire ; par conséquent, cette méthode est une opération O(n), où n est égal à Count.
ExempleL'exemple de code suivant montre la méthode Contains et de nombreuses autres propriétés et méthodes de la classe générique List. Une fois la liste remplie, la méthode Contains est utilisée pour rechercher un élément.
Imports System Imports System.Collections.Generic Public Class Example Public Shared Sub Main() Dim dinosaurs As New List(Of String) Console.WriteLine(vbLf & "Capacity: {0}", dinosaurs.Capacity) dinosaurs.Add("Tyrannosaurus") dinosaurs.Add("Amargasaurus") dinosaurs.Add("Mamenchisaurus") dinosaurs.Add("Deinonychus") dinosaurs.Add("Compsognathus") Console.WriteLine() For Each dinosaur As String In dinosaurs Console.WriteLine(dinosaur) Next Console.WriteLine(vbLf & "Capacity: {0}", dinosaurs.Capacity) Console.WriteLine("Count: {0}", dinosaurs.Count) Console.WriteLine(vbLf & "Contains(""Deinonychus""): {0}", _ dinosaurs.Contains("Deinonychus")) Console.WriteLine(vbLf & "Insert(2, ""Compsognathus"")") dinosaurs.Insert(2, "Compsognathus") Console.WriteLine() For Each dinosaur As String In dinosaurs Console.WriteLine(dinosaur) Next Console.WriteLine(vbLf & "dinosaurs(3): {0}", dinosaurs(3)) Console.WriteLine(vbLf & "Remove(""Compsognathus"")") dinosaurs.Remove("Compsognathus") Console.WriteLine() For Each dinosaur As String In dinosaurs Console.WriteLine(dinosaur) Next dinosaurs.TrimExcess() Console.WriteLine(vbLf & "TrimExcess()") Console.WriteLine("Capacity: {0}", dinosaurs.Capacity) Console.WriteLine("Count: {0}", dinosaurs.Count) dinosaurs.Clear() Console.WriteLine(vbLf & "Clear()") Console.WriteLine("Capacity: {0}", dinosaurs.Capacity) Console.WriteLine("Count: {0}", dinosaurs.Count) End Sub End Class ' This code example produces the following output: ' 'Capacity: 0 ' 'Tyrannosaurus 'Amargasaurus 'Mamenchisaurus 'Deinonychus 'Compsognathus ' 'Capacity: 8 'Count: 5 ' 'Contains("Deinonychus"): True ' 'Insert(2, "Compsognathus") ' 'Tyrannosaurus 'Amargasaurus 'Compsognathus 'Mamenchisaurus 'Deinonychus 'Compsognathus ' 'dinosaurs(3): Mamenchisaurus ' 'Remove("Compsognathus") ' 'Tyrannosaurus 'Amargasaurus 'Mamenchisaurus 'Deinonychus 'Compsognathus ' 'TrimExcess() 'Capacity: 5 'Count: 5 ' 'Clear() 'Capacity: 5 'Count: 0
using System; using System.Collections.Generic; public class Example { public static void Main() { List<string> dinosaurs = new List<string>(); Console.WriteLine("\nCapacity: {0}", dinosaurs.Capacity); dinosaurs.Add("Tyrannosaurus"); dinosaurs.Add("Amargasaurus"); dinosaurs.Add("Mamenchisaurus"); dinosaurs.Add("Deinonychus"); dinosaurs.Add("Compsognathus"); Console.WriteLine(); foreach(string dinosaur in dinosaurs) { Console.WriteLine(dinosaur); } Console.WriteLine("\nCapacity: {0}", dinosaurs.Capacity); Console.WriteLine("Count: {0}", dinosaurs.Count); Console.WriteLine("\nContains(\"Deinonychus\"): {0}", dinosaurs.Contains("Deinonychus")); Console.WriteLine("\nInsert(2, \"Compsognathus\")"); dinosaurs.Insert(2, "Compsognathus"); Console.WriteLine(); foreach(string dinosaur in dinosaurs) { Console.WriteLine(dinosaur); } Console.WriteLine("\ndinosaurs[3]: {0}", dinosaurs[3]); Console.WriteLine("\nRemove(\"Compsognathus\")"); dinosaurs.Remove("Compsognathus"); Console.WriteLine(); foreach(string dinosaur in dinosaurs) { Console.WriteLine(dinosaur); } dinosaurs.TrimExcess(); Console.WriteLine("\nTrimExcess()"); Console.WriteLine("Capacity: {0}", dinosaurs.Capacity); Console.WriteLine("Count: {0}", dinosaurs.Count); dinosaurs.Clear(); Console.WriteLine("\nClear()"); Console.WriteLine("Capacity: {0}", dinosaurs.Capacity); Console.WriteLine("Count: {0}", dinosaurs.Count); } } /* This code example produces the following output: Capacity: 0 Tyrannosaurus Amargasaurus Mamenchisaurus Deinonychus Compsognathus Capacity: 8 Count: 5 Contains("Deinonychus"): True Insert(2, "Compsognathus") Tyrannosaurus Amargasaurus Compsognathus Mamenchisaurus Deinonychus Compsognathus dinosaurs[3]: Mamenchisaurus Remove("Compsognathus") Tyrannosaurus Amargasaurus Mamenchisaurus Deinonychus Compsognathus TrimExcess() Capacity: 5 Count: 5 Clear() Capacity: 5 Count: 0 */
using namespace System; using namespace System::Collections::Generic; void main() { List<String^>^ dinosaurs = gcnew List<String^>(); Console::WriteLine("\nCapacity: {0}", dinosaurs->Capacity); dinosaurs->Add("Tyrannosaurus"); dinosaurs->Add("Amargasaurus"); dinosaurs->Add("Mamenchisaurus"); dinosaurs->Add("Deinonychus"); dinosaurs->Add("Compsognathus"); Console::WriteLine(); for each(String^ dinosaur in dinosaurs ) { Console::WriteLine(dinosaur); } Console::WriteLine("\nCapacity: {0}", dinosaurs->Capacity); Console::WriteLine("Count: {0}", dinosaurs->Count); Console::WriteLine("\nContains(\"Deinonychus\"): {0}", dinosaurs->Contains("Deinonychus")); Console::WriteLine("\nInsert(2, \"Compsognathus\")"); dinosaurs->Insert(2, "Compsognathus"); Console::WriteLine(); for each(String^ dinosaur in dinosaurs ) { Console::WriteLine(dinosaur); } Console::WriteLine("\ndinosaurs[3]: {0}", dinosaurs[3]); Console::WriteLine("\nRemove(\"Compsognathus\")"); dinosaurs->Remove("Compsognathus"); Console::WriteLine(); for each(String^ dinosaur in dinosaurs ) { Console::WriteLine(dinosaur); } dinosaurs->TrimExcess(); Console::WriteLine("\nTrimExcess()"); Console::WriteLine("Capacity: {0}", dinosaurs->Capacity); Console::WriteLine("Count: {0}", dinosaurs->Count); dinosaurs->Clear(); Console::WriteLine("\nClear()"); Console::WriteLine("Capacity: {0}", dinosaurs->Capacity); Console::WriteLine("Count: {0}", dinosaurs->Count); } /* This code example produces the following output: Capacity: 0 Tyrannosaurus Amargasaurus Mamenchisaurus Deinonychus Compsognathus Capacity: 8 Count: 5 Contains("Deinonychus"): True Insert(2, "Compsognathus") Tyrannosaurus Amargasaurus Compsognathus Mamenchisaurus Deinonychus Compsognathus dinosaurs[3]: Mamenchisaurus Remove("Compsognathus") Tyrannosaurus Amargasaurus Mamenchisaurus Deinonychus Compsognathus TrimExcess() Capacity: 5 Count: 5 Clear() Capacity: 5 Count: 0 */
Plates-formesWindows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile pour Pocket PC, Windows Mobile pour Smartphone, Windows Server 2003, Windows XP Édition Media Center, Windows XP Professionnel Édition x64, Windows XP SP2, Windows XP Starter Edition
Le .NET Framework ne prend pas en charge toutes les versions de chaque plate-forme. Pour obtenir la liste des versions prises en charge, consultez Configuration requise.
Outils (masquer)
S'enregistrer
Liste des Membres
Qui est en ligne?
FAQ