Type.Equals Metodo

public:
 bool Equals(Type ^ o);

public:
 virtual bool Equals(Type ^ o);

public bool Equals (Type o);

public virtual bool Equals (Type? o);

public virtual bool Equals (Type o);

override this.Equals : Type -> bool

Public Function Equals (o As Type) As Boolean

Public Overridable Function Equals (o As Type) As Boolean

Parametri

Restituisce

Boolean

true se il tipo di sistema sottostante di o coincide con il tipo di sistema sottostante dell'oggetto Type corrente; in caso contrario, false.true if the underlying system type of o is the same as the underlying system type of the current Type; otherwise, false.

Implementazioni

Esempio

Nell'esempio seguente viene usato Equals per confrontare due tipi.The following example uses Equals to compare two types.

using System;
using System.Reflection;

class Example
{
    public static void Main()
    {

        Type a = typeof(System.String);
        Type b = typeof(System.Int32);

        Console.WriteLine("{0} == {1}: {2}", a, b, a.Equals(b));

        // The Type objects in a and b are not equal,
        // because they represent different types.

        a = typeof(Example);
        b = new Example().GetType();

        Console.WriteLine("{0} is equal to {1}: {2}", a, b, a.Equals(b));

        // The Type objects in a and b are equal,
        // because they both represent type Example.

        b = typeof(Type);

        Console.WriteLine("typeof({0}).Equals(typeof({1})): {2}", a, b, a.Equals(b));

        // The Type objects in a and b are not equal,
        // because variable a represents type Example
        // and variable b represents type Type.

        //Console.ReadLine();
    }
}

//
/* This code example produces the following output:
    System.String == System.Int32: False
    Example is equal to Example: True
    typeof(Example).Equals(typeof(System.Type)): False
*/

Imports System.Reflection



Class Example
    
    Public Shared Sub Main() 
        
        Dim a As Type = GetType(System.String)
        Dim b As Type = GetType(System.Int32)
        
        Console.WriteLine("{0} = {1}: {2}", a, b, a.Equals(b))
        ' The Type objects in a and b are not equal,
        ' because they represent different types.

        a = GetType(Example)
        b = New Example().GetType()
        Console.WriteLine("{0} is equal to {1}: {2}", a, b, a.Equals(b))
        ' The Type objects in a and b are equal,
        ' because they both represent type Example.

        b = GetType(Type)
        Console.WriteLine("typeof({0}).Equals(typeof({1})): {2}", a, b, a.Equals(b))
        ' The Type objects in a and b are not equal,
        ' because variable a represents type Example
        ' and variable b represents type Type.

        'Console.ReadLine()
    
    End Sub 
End Class
'
' This code example produces the following output:
'    System.String = System.Int32: False
'    Example is equal to Example: True
'    typeof(Example).Equals(typeof(System.Type)): False
'

Vedi anche

• UnderlyingSystemType

public:
 override bool Equals(System::Object ^ o);

public override bool Equals (object o);

public override bool Equals (object? o);

override this.Equals : obj -> bool

Public Overrides Function Equals (o As Object) As Boolean

Parametri

Restituisce

Boolean

true se il tipo di sistema sottostante di o coincide con il tipo di sistema sottostante dell'oggetto Type corrente; in caso contrario, false.true if the underlying system type of o is the same as the underlying system type of the current Type; otherwise, false. Questo metodo restituisce false anche quando:This method also returns false if:

• o è null.

o is null.

Impossibile eseguire il cast o la conversione di o in un oggetto Type.

o cannot be cast or converted to a Type object.

Implementazioni

Esempio

Nell'esempio seguente viene utilizzato Equals(Object) per confrontare varie Type istanze di oggetti con varie Object istanze.The following example uses Equals(Object) to compare various Type object instances with various Object instances.

using System;
using System.Collections.Generic;
using System.Reflection;

public class Example
{
   public static void Main()
   {
      Type t =typeof(int);
      Object obj1 = typeof(int).GetTypeInfo();
      IsEqualTo(t, obj1);

      Object obj2 = typeof(String);
      IsEqualTo(t, obj2);
      
      t = typeof(Object);
      Object obj3 = typeof(Object);
      IsEqualTo(t, obj3);
      
      t = typeof(List<>);
      Object obj4 = (new List<String>()).GetType();
      IsEqualTo(t, obj4);
      
      t = typeof(Type);
      Object obj5 = null;
      IsEqualTo(t, obj5);
   }
   
   private static void IsEqualTo(Type t, Object inst)
   {
      Type t2 = inst as Type;
      if (t2 != null)
         Console.WriteLine("{0} = {1}: {2}", t.Name, t2.Name,
                           t.Equals(t2));
      else
         Console.WriteLine("Cannot cast the argument to a type.");

      Console.WriteLine();                        
   }
}
// The example displays the following output:
//       Int32 = Int32: True
//       
//       Int32 = String: False
//       
//       Object = Object: True
//       
//       List`1 = List`1: False
//       
//       Cannot cast the argument to a type.

Imports System.Collections.Generic
Imports System.Reflection

Module Example
   Public Sub Main()
      Dim t As Type = GetType(Integer)
      Dim obj1 As Object = GetType(Integer).GetTypeInfo()
      IsEqualTo(t, obj1)

      Dim obj2 As Object = GetType(String)
      IsEqualTo(t, obj2)
      
      t = GetType(Object)
      Dim obj3 As Object = GetType(Object)
      IsEqualTo(t, obj3)
      
      t = GetType(List(Of ))
      Dim obj4 As Object = (New List(Of String())).GetType()
      IsEqualTo(t, obj4)
      
      t = GetType(Type)
      Dim obj5 As Object = Nothing
      IsEqualTo(t, obj5)
   End Sub
   
   Private Sub IsEqualTo(t As Type, inst As Object)
      Dim t2 As Type = TryCast(inst, Type)
      If t2 IsNot Nothing Then
         Console.WriteLine("{0} = {1}: {2}", t.Name, t2.Name,
                           t.Equals(t2))
      Else
         Console.WriteLine("Cannot cast the argument to a type.")
      End If
      Console.WriteLine()                        
   End Sub
End Module
' The example displays the following output:
'       Int32 = Int32: True
'       
'       Int32 = String: False
'       
'       Object = Object: True
'       
'       List`1 = List`1: False
'       
'       Cannot cast the argument to a type.

In particolare, vale la pena notare l'esempio:Two things are particularly worth noting about the example:

• Confronto di un Type oggetto che rappresenta un integer con un TypeInfo oggetto che rappresenta un valore restituito integer true perché TypeInfo è derivato da Type .The comparison of a Type object that represents an integer with a TypeInfo object that represents an integer return true because TypeInfo is derived from Type.

• Il confronto di un Type oggetto che rappresenta un IList<T> oggetto, ovvero un tipo generico aperto, con un List(Of String) oggetto, ovvero un tipo generico chiuso, restituisce false .The comparison of a Type object that represents a IList<T> object (an open generic type) with a List(Of String) object (a closed generic type) returns false.

Commenti

Questo metodo esegue l'override di Object.Equals.This method overrides Object.Equals. Esegue il cast o a un oggetto di tipo Type e chiama il Type.Equals(Type) metodo.It casts o to an object of type Type and calls the Type.Equals(Type) method.

Vedi anche

• UnderlyingSystemType