Object.GetType Object.GetType Object.GetType Object.GetType Method

定義

取得目前執行個體的 TypeGets the Type of the current instance.

public:
 Type ^ GetType();
public Type GetType ();
member this.GetType : unit -> Type
Public Function GetType () As Type

傳回

目前執行個體的確切執行階段類型。The exact runtime type of the current instance.

範例

下列程式碼範例示範GetType傳回目前的執行個體的執行階段類型。The following code example demonstrates that GetType returns the runtime type of the current instance.

using namespace System;

public ref class MyBaseClass {};

public ref class MyDerivedClass: MyBaseClass{};

int main()
{
   MyBaseClass^ myBase = gcnew MyBaseClass;
   MyDerivedClass^ myDerived = gcnew MyDerivedClass;
   Object^ o = myDerived;
   MyBaseClass^ b = myDerived;
   Console::WriteLine( "mybase: Type is {0}", myBase->GetType() );
   Console::WriteLine( "myDerived: Type is {0}", myDerived->GetType() );
   Console::WriteLine( "object o = myDerived: Type is {0}", o->GetType() );
   Console::WriteLine( "MyBaseClass b = myDerived: Type is {0}", b->GetType() );
}

/*

This code produces the following output.

mybase: Type is MyBaseClass
myDerived: Type is MyDerivedClass
object o = myDerived: Type is MyDerivedClass
MyBaseClass b = myDerived: Type is MyDerivedClass 

*/
using System;

public class MyBaseClass {
}

public class MyDerivedClass: MyBaseClass {
}

public class Test 
{
   public static void Main() 
   {
      MyBaseClass myBase = new MyBaseClass();
      MyDerivedClass myDerived = new MyDerivedClass();
      object o = myDerived;
      MyBaseClass b = myDerived;

      Console.WriteLine("mybase: Type is {0}", myBase.GetType());
      Console.WriteLine("myDerived: Type is {0}", myDerived.GetType());
      Console.WriteLine("object o = myDerived: Type is {0}", o.GetType());
      Console.WriteLine("MyBaseClass b = myDerived: Type is {0}", b.GetType());
   }
}
// The example displays the following output:
//    mybase: Type is MyBaseClass
//    myDerived: Type is MyDerivedClass
//    object o = myDerived: Type is MyDerivedClass
//    MyBaseClass b = myDerived: Type is MyDerivedClass 
' Define a base and a derived class.
Public Class MyBaseClass
End Class 

Public Class MyDerivedClass : Inherits MyBaseClass
End Class 

Public Class Test
    Public Shared Sub Main() 
        Dim base As New MyBaseClass()
        Dim derived As New MyDerivedClass()
        Dim o As Object = derived
        Dim b As MyBaseClass = derived
        
        Console.WriteLine("base.GetType returns {0}", base.GetType())
        Console.WriteLine("derived.GetType returns {0}", derived.GetType())
        Console.WriteLine("Dim o As Object = derived; o.GetType returns {0}", o.GetType())
        Console.WriteLine("Dim b As MyBaseClass = derived; b.Type returns {0}", b.GetType())
    End Sub 
End Class 
' The example displays the following output:
'    base.GetType returns MyBaseClass
'    derived.GetType returns MyDerivedClass
'    Dim o As Object = derived; o.GetType returns MyDerivedClass
'    Dim b As MyBaseClass = derived; b.Type returns MyDerivedClass

備註

因為System.Object是基底類別,在.NET 中的所有類型中,輸入系統GetType方法可以用來傳回Type代表所有的.NET 類型的物件。Because System.Object is the base class for all types in the .NET type system, the GetType method can be used to return Type objects that represent all .NET types. .NET 可辨識下列五種型別:.NET recognizes the following five categories of types:

兩個物件xy具有相同的執行階段類型Object.ReferenceEquals(x.GetType(),y.GetType())傳回trueFor two objects x and y that have identical runtime types, Object.ReferenceEquals(x.GetType(),y.GetType()) returns true. 下列範例會使用GetType方法使用ReferenceEquals方法來判斷兩個數值是否為兩個數字的值相同的型別。The following example uses the GetType method with the ReferenceEquals method to determine whether one numeric value is the same type as two other numeric values.

using System;

public class Example
{
   public static void Main()
   {
      int n1 = 12;
      int n2 = 82;
      long n3 = 12;
      
      Console.WriteLine("n1 and n2 are the same type: {0}",
                        Object.ReferenceEquals(n1.GetType(), n2.GetType()));
      Console.WriteLine("n1 and n3 are the same type: {0}",
                        Object.ReferenceEquals(n1.GetType(), n3.GetType()));
   }
}
// The example displays the following output:
//       n1 and n2 are the same type: True
//       n1 and n3 are the same type: False      
Module Example
   Public Sub Main()
      Dim n1 As Integer = 12
      Dim n2 As Integer = 82
      Dim n3 As Long = 12
      
      Console.WriteLine("n1 and n2 are the same type: {0}",
                        Object.ReferenceEquals(n1.GetType(), n2.GetType()))
      Console.WriteLine("n1 and n3 are the same type: {0}",
                        Object.ReferenceEquals(n1.GetType(), n3.GetType()))
   End Sub
End Module
' The example displays the following output:
'       n1 and n2 are the same type: True
'       n1 and n3 are the same type: False      

注意

若要判斷物件是否為特定的型別,您可以使用您語言的型別比較關鍵字,或建構。To determine whether an object is a specific type, you can use your language's type comparison keyword or construct. 例如,您可以使用TypeOf…Is在 Visual Basic 中建構或isC# 中的關鍵字。For example, you can use the TypeOf…Is construct in Visual Basic or the is keyword in C#.

GetType方法繼承自所有的型別衍生自ObjectThe GetType method is inherited by all types that derive from Object. 這表示,除了使用您自己的語言比較關鍵字,您可以使用GetType方法,以判斷特定物件的型別,如下列範例所示。This means that, in addition to using your own language's comparison keyword, you can use the GetType method to determine the type of a particular object, as the following example shows.

using System;

public class Example
{
   public static void Main()
   {
      object[] values = { (int) 12, (long) 10653, (byte) 12, (sbyte) -5,
                         16.3, "string" }; 
      foreach (var value in values) {
         Type t = value.GetType();
         if (t.Equals(typeof(byte)))
            Console.WriteLine("{0} is an unsigned byte.", value);
         else if (t.Equals(typeof(sbyte)))
            Console.WriteLine("{0} is a signed byte.", value);
         else if (t.Equals(typeof(int)))   
            Console.WriteLine("{0} is a 32-bit integer.", value);
         else if (t.Equals(typeof(long)))   
            Console.WriteLine("{0} is a 32-bit integer.", value);
         else if (t.Equals(typeof(double)))
            Console.WriteLine("{0} is a double-precision floating point.", 
                              value);
         else
            Console.WriteLine("'{0}' is another data type.", value);
      }
   }
}
// The example displays the following output:
//    12 is a 32-bit integer.
//    10653 is a 32-bit integer.
//    12 is an unsigned byte.
//    -5 is a signed byte.
//    16.3 is a double-precision floating point.
//    'string' is another data type.
Module Example
   Public Sub Main()
      Dim values() As Object = { 12, CLng(10653), CByte(12), 
                                 CSbyte(-5), 16.3, "string" } 
      For Each value In values
         Dim t AS Type = value.GetType()
         If t.Equals(GetType(Byte))
            Console.WriteLine("{0} is an unsigned byte.", value)
         ElseIf t.Equals(GetType(SByte))
            Console.WriteLine("{0} is a signed byte.", value)
         ElseIf t.Equals(GetType(Integer))   
            Console.WriteLine("{0} is a 32-bit integer.", value)
         ElseIf t.Equals(GetType(Long))   
            Console.WriteLine("{0} is a 32-bit integer.", value)
         ElseIf t.Equals(GetType(Double))
            Console.WriteLine("{0} is a double-precision floating point.", 
                              value)
         Else
            Console.WriteLine("'{0}' is another data type.", value)
         End If   
      Next      
   End Sub
End Module
' The example displays the following output:
'       12 is a 32-bit integer.
'       10653 is a 32-bit integer.
'       12 is an unsigned byte.
'       -5 is a signed byte.
'       16.3 is a double-precision floating point.
'       'string' is another data type.

Type物件會公開目前的類別相關聯的中繼資料ObjectThe Type object exposes the metadata associated with the class of the current Object.

適用於

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