Enumerable.Intersect Methode

Definition

Erzeugt die Schnittmenge zweier SequenzenProduces the set intersection of two sequences.

Überlädt

Intersect<TSource>(IEnumerable<TSource>, IEnumerable<TSource>, IEqualityComparer<TSource>)

Erzeugt mithilfe des angegebenen IEqualityComparer<T> zum Vergleichen von Werten die Schnittmenge von zwei SequenzenProduces the set intersection of two sequences by using the specified IEqualityComparer<T> to compare values.

Intersect<TSource>(IEnumerable<TSource>, IEnumerable<TSource>)

Erzeugt die Schnittmenge zweier Sequenzen mithilfe des Standardgleichheitsvergleichs zum Vergleichen von WertenProduces the set intersection of two sequences by using the default equality comparer to compare values.

Intersect<TSource>(IEnumerable<TSource>, IEnumerable<TSource>, IEqualityComparer<TSource>)

Erzeugt mithilfe des angegebenen IEqualityComparer<T> zum Vergleichen von Werten die Schnittmenge von zwei SequenzenProduces the set intersection of two sequences by using the specified IEqualityComparer<T> to compare values.

public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
 static System::Collections::Generic::IEnumerable<TSource> ^ Intersect(System::Collections::Generic::IEnumerable<TSource> ^ first, System::Collections::Generic::IEnumerable<TSource> ^ second, System::Collections::Generic::IEqualityComparer<TSource> ^ comparer);
public static System.Collections.Generic.IEnumerable<TSource> Intersect<TSource> (this System.Collections.Generic.IEnumerable<TSource> first, System.Collections.Generic.IEnumerable<TSource> second, System.Collections.Generic.IEqualityComparer<TSource> comparer);
public static System.Collections.Generic.IEnumerable<TSource> Intersect<TSource> (this System.Collections.Generic.IEnumerable<TSource> first, System.Collections.Generic.IEnumerable<TSource> second, System.Collections.Generic.IEqualityComparer<TSource>? comparer);
static member Intersect : seq<'Source> * seq<'Source> * System.Collections.Generic.IEqualityComparer<'Source> -> seq<'Source>
<Extension()>
Public Function Intersect(Of TSource) (first As IEnumerable(Of TSource), second As IEnumerable(Of TSource), comparer As IEqualityComparer(Of TSource)) As IEnumerable(Of TSource)

Typparameter

TSource

Der Typ der Elemente der Eingabesequenzen.The type of the elements of the input sequences.

Parameter

first
IEnumerable<TSource>

Ein IEnumerable<T>, dessen unterschiedliche Elemente auch in second vorhanden sind, wird zurückgegeben.An IEnumerable<T> whose distinct elements that also appear in second will be returned.

second
IEnumerable<TSource>

Ein IEnumerable<T>, dessen unterschiedliche Elemente auch in der ersten Sequenz vorhanden sind, wird zurückgegeben.An IEnumerable<T> whose distinct elements that also appear in the first sequence will be returned.

comparer
IEqualityComparer<TSource>

Ein IEqualityComparer<T> zum Vergleichen von Werten.An IEqualityComparer<T> to compare values.

Gibt zurück

IEnumerable<TSource>

Eine Sequenz, die die Elemente enthält, die die Schnittmenge von zwei Sequenzen bilden.A sequence that contains the elements that form the set intersection of two sequences.

Ausnahmen

first oder second ist null.first or second is null.

Beispiele

Im folgenden Beispiel wird gezeigt, wie ein Gleichheits Vergleich implementiert wird, der in der-Methode verwendet werden kann Intersect .The following example shows how to implement an equality comparer that can be used in the Intersect method.

public class Product
{
    public string Name { get; set; }
    public int Code { get; set; }
}

// Custom comparer for the Product class
class ProductComparer : IEqualityComparer<Product>
{
    // Products are equal if their names and product numbers are equal.
    public bool Equals(Product x, Product y)
    {

        //Check whether the compared objects reference the same data.
        if (Object.ReferenceEquals(x, y)) return true;

        //Check whether any of the compared objects is null.
        if (Object.ReferenceEquals(x, null) || Object.ReferenceEquals(y, null))
            return false;

        //Check whether the products' properties are equal.
        return x.Code == y.Code && x.Name == y.Name;
    }

    // If Equals() returns true for a pair of objects
    // then GetHashCode() must return the same value for these objects.

    public int GetHashCode(Product product)
    {
        //Check whether the object is null
        if (Object.ReferenceEquals(product, null)) return 0;

        //Get hash code for the Name field if it is not null.
        int hashProductName = product.Name == null ? 0 : product.Name.GetHashCode();

        //Get hash code for the Code field.
        int hashProductCode = product.Code.GetHashCode();

        //Calculate the hash code for the product.
        return hashProductName ^ hashProductCode;
    }
}
Public Class Product
    Public Property Name As String
    Public Property Code As Integer
End Class

' Custom comparer for the Product class
Public Class ProductComparer
    Implements IEqualityComparer(Of Product)

    Public Function Equals1(
        ByVal x As Product, 
        ByVal y As Product
        ) As Boolean Implements IEqualityComparer(Of Product).Equals

        ' Check whether the compared objects reference the same data.
        If x Is y Then Return True

        'Check whether any of the compared objects is null.
        If x Is Nothing OrElse y Is Nothing Then Return False

        ' Check whether the products' properties are equal.
        Return (x.Code = y.Code) AndAlso (x.Name = y.Name)
    End Function

    Public Function GetHashCode1(
        ByVal product As Product
        ) As Integer Implements IEqualityComparer(Of Product).GetHashCode

        ' Check whether the object is null.
        If product Is Nothing Then Return 0

        ' Get hash code for the Name field if it is not null.
        Dim hashProductName = 
            If(product.Name Is Nothing, 0, product.Name.GetHashCode())

        ' Get hash code for the Code field.
        Dim hashProductCode = product.Code.GetHashCode()

        ' Calculate the hash code for the product.
        Return hashProductName Xor hashProductCode
    End Function
End Class

Nachdem Sie diesen Vergleich implementiert haben, können Sie Sequenzen von Product Objekten in der- Intersect Methode verwenden, wie im folgenden Beispiel gezeigt:After you implement this comparer, you can use sequences of Product objects in the Intersect method, as shown in the following example:

Product[] store1 = { new Product { Name = "apple", Code = 9 },
                       new Product { Name = "orange", Code = 4 } };

Product[] store2 = { new Product { Name = "apple", Code = 9 },
                       new Product { Name = "lemon", Code = 12 } };
Dim store1() As Product = 
    {New Product With {.Name = "apple", .Code = 9}, 
     New Product With {.Name = "orange", .Code = 4}}

Dim store2() As Product = 
    {New Product With {.Name = "apple", .Code = 9}, 
     New Product With {.Name = "lemon", .Code = 12}}
// Get the products from the first array
// that have duplicates in the second array.

IEnumerable<Product> duplicates =
    store1.Intersect(store2, new ProductComparer());

foreach (var product in duplicates)
    Console.WriteLine(product.Name + " " + product.Code);

/*
    This code produces the following output:
    apple 9
*/
' Get the products from the first array 
' that have duplicates in the second array.

Dim duplicates = store1.Intersect(store2, New ProductComparer())

For Each product In duplicates
    Console.WriteLine(product.Name & " " & product.Code)
Next

' This code produces the following output:
'
' apple 9
' 

Hinweise

Diese Methode wird mithilfe von verzögerter Ausführung implementiert.This method is implemented by using deferred execution. Der unmittelbare Rückgabewert ist ein Objekt, das alle Informationen speichert, die zum Ausführen der Aktion erforderlich sind.The immediate return value is an object that stores all the information that is required to perform the action. Die durch diese Methode dargestellte Abfrage wird erst ausgeführt, wenn das Objekt durch Aufrufen der- GetEnumerator Methode direkt oder mithilfe von foreach in Visual c# oder in Visual Basic aufgezählt wird For Each .The query represented by this method is not executed until the object is enumerated either by calling its GetEnumerator method directly or by using foreach in Visual C# or For Each in Visual Basic.

Die Schnittmenge von zwei Sätzen a und B wird als der Satz definiert, der alle Elemente von enthält, die auch in B, aber keine anderen Elemente enthalten sind.The intersection of two sets A and B is defined as the set that contains all the elements of A that also appear in B, but no other elements.

Wenn das Objekt, das von dieser Methode zurückgegeben wird, aufgelistet wird, werden Intersect in beiden Sequenzen in der Reihenfolge, in der Sie angezeigt werden, unterschiedliche Elemente erzeugt first .When the object returned by this method is enumerated, Intersect yields distinct elements occurring in both sequences in the order in which they appear in first.

Wenn comparer null den Wert hat, wird der Standard Gleichheits Vergleich Default verwendet, um Werte zu vergleichen.If comparer is null, the default equality comparer, Default, is used to compare values.

Gilt für:

Intersect<TSource>(IEnumerable<TSource>, IEnumerable<TSource>)

Erzeugt die Schnittmenge zweier Sequenzen mithilfe des Standardgleichheitsvergleichs zum Vergleichen von WertenProduces the set intersection of two sequences by using the default equality comparer to compare values.

public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
 static System::Collections::Generic::IEnumerable<TSource> ^ Intersect(System::Collections::Generic::IEnumerable<TSource> ^ first, System::Collections::Generic::IEnumerable<TSource> ^ second);
public static System.Collections.Generic.IEnumerable<TSource> Intersect<TSource> (this System.Collections.Generic.IEnumerable<TSource> first, System.Collections.Generic.IEnumerable<TSource> second);
static member Intersect : seq<'Source> * seq<'Source> -> seq<'Source>
<Extension()>
Public Function Intersect(Of TSource) (first As IEnumerable(Of TSource), second As IEnumerable(Of TSource)) As IEnumerable(Of TSource)

Typparameter

TSource

Der Typ der Elemente der Eingabesequenzen.The type of the elements of the input sequences.

Parameter

first
IEnumerable<TSource>

Ein IEnumerable<T>, dessen unterschiedliche Elemente auch in second vorhanden sind, wird zurückgegeben.An IEnumerable<T> whose distinct elements that also appear in second will be returned.

second
IEnumerable<TSource>

Ein IEnumerable<T>, dessen unterschiedliche Elemente auch in der ersten Sequenz vorhanden sind, wird zurückgegeben.An IEnumerable<T> whose distinct elements that also appear in the first sequence will be returned.

Gibt zurück

IEnumerable<TSource>

Eine Sequenz, die die Elemente enthält, die die Schnittmenge von zwei Sequenzen bilden.A sequence that contains the elements that form the set intersection of two sequences.

Ausnahmen

first oder second ist null.first or second is null.

Beispiele

Im folgenden Codebeispiel wird veranschaulicht, wie verwendet wird, Intersect<TSource>(IEnumerable<TSource>, IEnumerable<TSource>) um die Elemente zurückzugeben, die in jeder der beiden Sequenzen von ganzen Zahlen angezeigt werden.The following code example demonstrates how to use Intersect<TSource>(IEnumerable<TSource>, IEnumerable<TSource>) to return the elements that appear in each of two sequences of integers.

int[] id1 = { 44, 26, 92, 30, 71, 38 };
int[] id2 = { 39, 59, 83, 47, 26, 4, 30 };

IEnumerable<int> both = id1.Intersect(id2);

foreach (int id in both)
    Console.WriteLine(id);

/*
 This code produces the following output:

 26
 30
*/
' Create two integer arrays.
Dim id1() As Integer = {44, 26, 92, 30, 71, 38}
Dim id2() As Integer = {39, 59, 83, 47, 26, 4, 30}

' Find the set intersection of the two arrays.
Dim intersection As IEnumerable(Of Integer) = id1.Intersect(id2)

Dim output As New System.Text.StringBuilder
For Each id As Integer In intersection
    output.AppendLine(id)
Next

' Display the output.
Console.WriteLine(output.ToString)

' This code produces the following output:
'
' 26
' 30

Wenn Sie Sequenzen von Objekten eines benutzerdefinierten Datentyps vergleichen möchten, müssen Sie die IEquatable<T> generische-Schnittstelle in einer Hilfsklasse implementieren.If you want to compare sequences of objects of some custom data type, you have to implement the IEquatable<T> generic interface in a helper class. Im folgenden Codebeispiel wird veranschaulicht, wie diese Schnittstelle in einem benutzerdefinierten Datentyp implementiert und die GetHashCode -und-Methoden überschrieben werden Equals .The following code example shows how to implement this interface in a custom data type and override GetHashCode and Equals methods.

public class ProductA: IEquatable<ProductA>
{
    public string Name { get; set; }
    public int Code { get; set; }

    public bool Equals(ProductA other)
    {
        if (other is null)
            return false;

        return this.Name == other.Name && this.Code == other.Code;
    }

    public override bool Equals(object obj) => Equals(obj as ProductA);
    public override int GetHashCode() => (Name, Code).GetHashCode();
}
Public Class ProductA
    Inherits IEquatable(Of ProductA)

    Public Property Name As String
    Public Property Code As Integer

    Public Function Equals(ByVal other As ProductA) As Boolean
        If other Is Nothing Then Return False
        Return Me.Name = other.Name AndAlso Me.Code = other.Code
    End Function

    Public Overrides Function Equals(ByVal obj As Object) As Boolean
        Return Equals(TryCast(obj, ProductA))
    End Function

    Public Overrides Function GetHashCode() As Integer
        Return (Name, Code).GetHashCode()
    End Function

End Class

Nachdem Sie diese Schnittstelle implementiert haben, können Sie Sequenzen von ProductA Objekten in der- Intersect Methode verwenden, wie im folgenden Beispiel gezeigt:After you implement this interface, you can use sequences of ProductA objects in the Intersect method, as shown in the following example:

ProductA[] store1 = { new ProductA { Name = "apple", Code = 9 },
                       new ProductA { Name = "orange", Code = 4 } };

ProductA[] store2 = { new ProductA { Name = "apple", Code = 9 },
                       new ProductA { Name = "lemon", Code = 12 } };
Dim store1() As ProductA = 
    {New Product With {.Name = "apple", .Code = 9}, 
     New Product With {.Name = "orange", .Code = 4}}

Dim store2() As ProductA = 
    {New Product With {.Name = "apple", .Code = 9}, 
     New Product With {.Name = "lemon", .Code = 12}}
// Get the products from the first array
// that have duplicates in the second array.

IEnumerable<ProductA> duplicates =
    store1.Intersect(store2);

foreach (var product in duplicates)
    Console.WriteLine(product.Name + " " + product.Code);

/*
    This code produces the following output:
    apple 9
*/
' Get the products from the first array 
' that have duplicates in the second array.

Dim duplicates = store1.Intersect(store2)

For Each product In duplicates
    Console.WriteLine(product.Name & " " & product.Code)
Next

' This code produces the following output:
'
' apple 9
' 

Hinweise

Diese Methode wird mithilfe von verzögerter Ausführung implementiert.This method is implemented by using deferred execution. Der unmittelbare Rückgabewert ist ein Objekt, das alle Informationen speichert, die zum Ausführen der Aktion erforderlich sind.The immediate return value is an object that stores all the information that is required to perform the action. Die durch diese Methode dargestellte Abfrage wird erst ausgeführt, wenn das Objekt durch Aufrufen der- GetEnumerator Methode direkt oder mithilfe von foreach in Visual c# oder in Visual Basic aufgezählt wird For Each .The query represented by this method is not executed until the object is enumerated either by calling its GetEnumerator method directly or by using foreach in Visual C# or For Each in Visual Basic.

Die Schnittmenge von zwei Sätzen a und B wird als der Satz definiert, der alle Elemente von enthält, die auch in B, aber keine anderen Elemente enthalten sind.The intersection of two sets A and B is defined as the set that contains all the elements of A that also appear in B, but no other elements.

Wenn das Objekt, das von dieser Methode zurückgegeben wird, aufgelistet wird, werden Intersect in beiden Sequenzen in der Reihenfolge, in der Sie angezeigt werden, unterschiedliche Elemente erzeugt first .When the object returned by this method is enumerated, Intersect yields distinct elements occurring in both sequences in the order in which they appear in first.

Der Standard Gleichheits Vergleich, Default , wird verwendet, um Werte der Typen zu vergleichen.The default equality comparer, Default, is used to compare values of the types. Um einen benutzerdefinierten Datentyp zu vergleichen, müssen Sie die Equals -Methode und die-Methode überschreiben GetHashCode und optional die IEquatable<T> generische-Schnittstelle im benutzerdefinierten Typ implementieren.To compare a custom data type, you need to override the Equals and the GetHashCode methods, and optionally implement the IEquatable<T> generic interface in the custom type. Weitere Informationen finden Sie in den Ausführungen zur Default-Eigenschaft.For more information, see the Default property.

Gilt für: