Type.IsInstanceOfType(Object) Metodo

Definizione

Spazio dei nomi:

System

Assembly:

System.Runtime.dll

Origine:

Type.cs

Determina se l'oggetto specificato è un'istanza dell'oggetto Type corrente.

public:
 virtual bool IsInstanceOfType(System::Object ^ o);

public virtual bool IsInstanceOfType (object? o);

abstract member IsInstanceOfType : obj -> bool
override this.IsInstanceOfType : obj -> bool

Public Overridable Function IsInstanceOfType (o As Object) As Boolean

Parametri

o

Object

Oggetto da confrontare con il tipo corrente.

Restituisce

Boolean

true se l'oggetto Type corrente è incluso nella gerarchia di ereditarietà dell'oggetto rappresentato da o oppure se l'oggetto Type corrente è un'interfaccia implementata da o. false se non viene soddisfatta nessuna di queste condizioni, se o è null oppure se l'oggetto Type corrente è un tipo generico aperto, ovvero la proprietà ContainsGenericParameters restituisce true.

Esempio

Nell'esempio seguente viene illustrato l'uso del metodo IsInstanceOfType.

using namespace System;

public interface class IExample{};

public ref class BaseClass: IExample{};

public ref class DerivedClass: BaseClass{};

void main()
{
   Type^ interfaceType = IExample::typeid;
   BaseClass^ base1 = gcnew BaseClass;
   Type^ base1Type = base1->GetType();
   BaseClass^ derived1 = gcnew DerivedClass;
   Type^ derived1Type = derived1->GetType();
   array<Int32>^ arr = gcnew array<Int32>(11);
   Type^ arrayType = Array::typeid;

   Console::WriteLine("Is Int32[] an instance of the Array class? {0}.",
                      arrayType->IsInstanceOfType( arr ) );
   Console::WriteLine("Is myclass an instance of BaseClass? {0}.",
                      base1Type->IsInstanceOfType( base1 ) );
   Console::WriteLine("Is myderivedclass an instance of BaseClass? {0}.",
                      base1Type->IsInstanceOfType( derived1 ) );
   Console::WriteLine("Is myclass an instance of IExample? {0}.",
                      interfaceType->IsInstanceOfType( base1 ) );
   Console::WriteLine("Is myderivedclass an instance of IExample? {0}.",
                      interfaceType->IsInstanceOfType( derived1 ) );
}
// The example displays the following output:
//    Is int[] an instance of the Array class? True.
//    Is base1 an instance of BaseClass? True.
//    Is derived1 an instance of BaseClass? True.
//    Is base1 an instance of IExample? True.
//    Is derived1 an instance of IExample? True.

using System;

public interface IExample {}

public class BaseClass : IExample {}

public class DerivedClass : BaseClass {}

public class Example
{
    public static void Main()
    {
        var interfaceType = typeof(IExample);
        var base1 = new BaseClass();
        var base1Type = base1.GetType();
        var derived1 = new DerivedClass();
        var derived1Type = derived1.GetType();
        int[] arr = new int[11];

        Console.WriteLine("Is int[] an instance of the Array class? {0}.",
                           typeof(Array).IsInstanceOfType(arr));
        Console.WriteLine("Is base1 an instance of BaseClass? {0}.",
                          base1Type.IsInstanceOfType(base1));
        Console.WriteLine("Is derived1 an instance of BaseClass? {0}.",
                          base1Type.IsInstanceOfType(derived1));
        Console.WriteLine("Is base1 an instance of IExample? {0}.",
                          interfaceType.IsInstanceOfType(base1));
        Console.WriteLine("Is derived1 an instance of IExample? {0}.",
                          interfaceType.IsInstanceOfType(derived1));
    }
}
// The example displays the following output:
//    Is int[] an instance of the Array class? True.
//    Is base1 an instance of BaseClass? True.
//    Is derived1 an instance of BaseClass? True.
//    Is base1 an instance of IExample? True.
//    Is derived1 an instance of IExample? True.

open System

type IExample = interface end

type BaseClass() = interface IExample

type DerivedClass() = inherit BaseClass()

let interfaceType = typeof<IExample>
let base1 = BaseClass()
let base1Type = base1.GetType()
let derived1 = DerivedClass()
let derived1Type = derived1.GetType()
let arr = Array.zeroCreate<int> 11

printfn $"Is int[] an instance of the Array class? {typeof<Array>.IsInstanceOfType arr}."
printfn $"Is base1 an instance of BaseClass? {base1Type.IsInstanceOfType base1}."
printfn $"Is derived1 an instance of BaseClass? {base1Type.IsInstanceOfType derived1}."
printfn $"Is base1 an instance of IExample? {interfaceType.IsInstanceOfType base1}."
printfn $"Is derived1 an instance of IExample? {interfaceType.IsInstanceOfType derived1}."
// The example displays the following output:
//    Is int[] an instance of the Array class? True.
//    Is base1 an instance of BaseClass? True.
//    Is derived1 an instance of BaseClass? True.
//    Is base1 an instance of IExample? True.
//    Is derived1 an instance of IExample? True.

Public Interface IExample
End Interface

Public Class BaseClass : Implements IExample
End Class

Public Class DerivedClass : Inherits BaseClass
End Class

Public Module Example
    Public Sub Main()
        Dim interfaceType As Type = GetType(IExample)
        Dim base1 As New BaseClass()
        Dim base1Type As Type = base1.GetType()
        Dim derived1 = New DerivedClass()
        Dim derived1Type As Type = derived1.GetType()
        Dim arr(10) As Integer

        Console.WriteLine("Is int[] an instance of the Array class? {0}.",
                           GetType(Array).IsInstanceOfType(arr))
        Console.WriteLine("Is base1 an instance of BaseClass? {0}.",
                          base1Type.IsInstanceOfType(base1))
        Console.WriteLine("Is derived1 an instance of BaseClass? {0}.",
                          base1Type.IsInstanceOfType(derived1))
        Console.WriteLine("Is base1 an instance of IExample? {0}.",
                          interfaceType.IsInstanceOfType(base1))
        Console.WriteLine("Is derived1 an instance of IExample? {0}.",
                          interfaceType.IsInstanceOfType(derived1))
    End Sub
End Module
' The example displays the following output:
'    Is int[] an instance of the Array class? True.
'    Is base1 an instance of BaseClass? True.
'    Is derived1 an instance of BaseClass? True.
'    Is base1 an instance of IExample? True.
'    Is derived1 an instance of IExample? True.

Commenti

Questo metodo può essere sottoposto a override da una classe derivata.

Nota

Un tipo costruito non è un'istanza della relativa definizione di tipo generico. Ovvero, MyGenericList<int> (MyGenericList(Of Integer) in Visual Basic) non è un'istanza di MyGenericList<T> (MyGenericList(Of T) in Visual Basic).