Object Object Object Object Class

定義

支援 .NET 類別階層架構中的所有類別,提供衍生類別的低階服務。Supports all classes in the .NET class hierarchy and provides low-level services to derived classes. 這是所有 .NET 類別的超基底類別,是類別階層架構的根。This is the ultimate base class of all .NET classes; it is the root of the type hierarchy.

public ref class Object
[System.Runtime.InteropServices.ClassInterface(System.Runtime.InteropServices.ClassInterfaceType.AutoDual)]
[System.Runtime.InteropServices.ComVisible(true)]
[System.Serializable]
public class Object
type obj = class
Public Class Object
屬性

範例

下列範例會定義點型別衍生自Object類別並覆寫的虛擬方法的許多Object類別。The following example defines a Point type derived from the Object class and overrides many of the virtual methods of the Object class. 此外,此範例示範如何呼叫許多靜態和執行個體方法的Object類別。In addition, the example shows how to call many of the static and instance methods of the Object class.

using namespace System;

// The Point class is derived from System.Object.
ref class Point
{
public:
    int x;
public:
    int y;

public:
    Point(int x, int y)
    {
        this->x = x;
        this->y = y;
    }

public:
    virtual bool Equals(Object^ obj) override
    {
        // If this and obj do not refer to the same type,
        // then they are not equal.
        if (obj->GetType() != this->GetType())
        {
            return false;
        }

        // Return true if  x and y fields match.
        Point^ other = (Point^) obj;
        return (this->x == other->x) && (this->y == other->y);
    }

    // Return the XOR of the x and y fields.
public:
    virtual int GetHashCode() override 
    {
        return x ^ y;
    }

    // Return the point's value as a string.
public:
    virtual String^ ToString() override 
    {
        return String::Format("({0}, {1})", x, y);
    }

    // Return a copy of this point object by making a simple
    // field copy.
public:
    Point^ Copy()
    {
        return (Point^) this->MemberwiseClone();
    }
};

int main()
{
    // Construct a Point object.
    Point^ p1 = gcnew Point(1, 2);

    // Make another Point object that is a copy of the first.
    Point^ p2 = p1->Copy();

    // Make another variable that references the first
    // Point object.
    Point^ p3 = p1;

    // The line below displays false because p1 and 
    // p2 refer to two different objects.
    Console::WriteLine(
        Object::ReferenceEquals(p1, p2));

    // The line below displays true because p1 and p2 refer
    // to two different objects that have the same value.
    Console::WriteLine(Object::Equals(p1, p2));

    // The line below displays true because p1 and 
    // p3 refer to one object.
    Console::WriteLine(Object::ReferenceEquals(p1, p3));

    // The line below displays: p1's value is: (1, 2)
    Console::WriteLine("p1's value is: {0}", p1->ToString());
}

// This code produces the following output.
//
// False
// True
// True
// p1's value is: (1, 2)
using System;

// The Point class is derived from System.Object.
class Point
{
    public int x, y;

    public Point(int x, int y) 
    {
        this.x = x;
        this.y = y;
    }
    
    public override bool Equals(object obj) 
    {
        // If this and obj do not refer to the same type, then they are not equal.
        if (obj.GetType() != this.GetType()) return false;

        // Return true if  x and y fields match.
        Point other = (Point) obj;
        return (this.x == other.x) && (this.y == other.y);
    }

    // Return the XOR of the x and y fields.
    public override int GetHashCode() 
    {
        return x ^ y;
    }

    // Return the point's value as a string.
    public override String ToString() 
    {
        return String.Format("({0}, {1})", x, y);
    }

    // Return a copy of this point object by making a simple field copy.
    public Point Copy() 
    {
        return (Point) this.MemberwiseClone();
    }
}

public sealed class App
{
    static void Main() 
    {
        // Construct a Point object.
        Point p1 = new Point(1,2);

        // Make another Point object that is a copy of the first.
        Point p2 = p1.Copy();

        // Make another variable that references the first Point object.
        Point p3 = p1;

        // The line below displays false because p1 and p2 refer to two different objects.
        Console.WriteLine(Object.ReferenceEquals(p1, p2));

        // The line below displays true because p1 and p2 refer to two different objects that have the same value.
        Console.WriteLine(Object.Equals(p1, p2));
      
        // The line below displays true because p1 and p3 refer to one object.
        Console.WriteLine(Object.ReferenceEquals(p1, p3));
        
        // The line below displays: p1's value is: (1, 2)
        Console.WriteLine("p1's value is: {0}", p1.ToString());
    }
}

// This code example produces the following output:
//
// False
// True
// True
// p1's value is: (1, 2)
//
' The Point class is derived from System.Object.
Class Point
    Public x, y As Integer
    
    Public Sub New(ByVal x As Integer, ByVal y As Integer) 
        Me.x = x
        Me.y = y
    End Sub
    
    Public Overrides Function Equals(ByVal obj As Object) As Boolean 
        ' If Me and obj do not refer to the same type, then they are not equal.
        Dim objType As Type = obj.GetType()
        Dim meType  As Type = Me.GetType()
        If Not objType.Equals(meType) Then
            Return False
        End If 
        ' Return true if  x and y fields match.
        Dim other As Point = CType(obj, Point)
        Return Me.x = other.x AndAlso Me.y = other.y
    End Function 

    ' Return the XOR of the x and y fields.
    Public Overrides Function GetHashCode() As Integer 
        Return (x << 1) XOr y
    End Function 

    ' Return the point's value as a string.
    Public Overrides Function ToString() As String 
        Return String.Format("({0}, {1})", x, y)
    End Function

    ' Return a copy of this point object by making a simple field copy.
    Public Function Copy() As Point 
        Return CType(Me.MemberwiseClone(), Point)
    End Function
End Class  

NotInheritable Public Class App
    Shared Sub Main() 
        ' Construct a Point object.
        Dim p1 As New Point(1, 2)
        
        ' Make another Point object that is a copy of the first.
        Dim p2 As Point = p1.Copy()
        
        ' Make another variable that references the first Point object.
        Dim p3 As Point = p1
        
        ' The line below displays false because p1 and p2 refer to two different objects.
        Console.WriteLine([Object].ReferenceEquals(p1, p2))

        ' The line below displays true because p1 and p2 refer to two different objects 
        ' that have the same value.
        Console.WriteLine([Object].Equals(p1, p2))

        ' The line below displays true because p1 and p3 refer to one object.
        Console.WriteLine([Object].ReferenceEquals(p1, p3))
        
        ' The line below displays: p1's value is: (1, 2)
        Console.WriteLine("p1's value is: {0}", p1.ToString())
    
    End Sub
End Class
' This example produces the following output:
'
' False
' True
' True
' p1's value is: (1, 2)
'

備註

語言通常不需要宣告繼承自類別Object因為繼承是隱含的。Languages typically do not require a class to declare inheritance from Object because the inheritance is implicit.

因為在.NET 中的所有類別都衍生自Object,每個方法中定義Object類別是所有的物件中的可用系統中。Because all classes in .NET are derived from Object, every method defined in the Object class is available in all objects in the system. 衍生類別並覆寫其中一些方法,包括:Derived classes can and do override some of these methods, including:

  • Equals -支援的物件之間的比較。Equals - Supports comparisons between objects.

  • Finalize -自動收回物件前,請執行清除作業。Finalize - Performs cleanup operations before an object is automatically reclaimed.

  • GetHashCode 產生對應至物件的值數目,以支援雜湊資料表的使用。GetHashCode - Generates a number corresponding to the value of the object to support the use of a hash table.

  • ToString -製造人類看得懂的文字字串描述類別的執行個體。ToString - Manufactures a human-readable text string that describes an instance of the class.

效能考量Performance Considerations

如果您正在設計的類別,例如集合、 必須處理任何類型的物件,您可以建立接受的執行個體的類別成員Object類別。If you are designing a class, such as a collection, that must handle any type of object, you can create class members that accept instances of the Object class. 不過,boxing 和 unboxing 類型的程序會帶來效能成本。However, the process of boxing and unboxing a type carries a performance cost. 如果您知道您的新類別會經常處理特定實值型別則您可以使用其中一個策略的 boxing 成本降到最低。If you know your new class will frequently handle certain value types you can use one of two tactics to minimize the cost of boxing.

  • 建立一般的方法可接受Object型別和一組特定類型的方法多載接受預期類別經常處理每一個實值型別。Create a general method that accepts an Object type, and a set of type-specific method overloads that accept each value type you expect your class to frequently handle. 如果特定類型的方法可接受呼叫的參數型別,就會發生任何 boxing,並叫用特定類型的方法。If a type-specific method exists that accepts the calling parameter type, no boxing occurs and the type-specific method is invoked. 如果沒有任何方法引數的比對呼叫的參數型別,參數會經過 boxing 處理,並叫用一般方法。If there is no method argument that matches the calling parameter type, the parameter is boxed and the general method is invoked.

  • 設計您的類型和其成員使用泛型。Design your type and its members to use generics. 當您建立您的類別的執行個體,並指定泛型型別引數時,common language runtime 就會建立封閉式的泛型型別。The common language runtime creates a closed generic type when you create an instance of your class and specify a generic type argument. 泛型方法型別特定,沒有 boxing 呼叫的參數就可以叫用。The generic method is type-specific and can be invoked without boxing the calling parameter.

雖然有時候是必要開發接受及傳回的一般用途類別Object類型,可以改善效能,也提供特定類型的類別來處理常使用的型別。Although it is sometimes necessary to develop general purpose classes that accept and return Object types, you can improve performance by also providing a type-specific class to handle a frequently used type. 比方說,提供特定設定和取得布林值的類別,可消除 boxing 和 unboxing 的布林值的成本。For example, providing a class that is specific to setting and getting Boolean values eliminates the cost of boxing and unboxing Boolean values.

建構函式

Object() Object() Object() Object()

初始化 Object 類別的新執行個體。Initializes a new instance of the Object class.

方法

Equals(Object) Equals(Object) Equals(Object) Equals(Object)

判斷指定的物件是否等於目前的物件。Determines whether the specified object is equal to the current object.

Equals(Object, Object) Equals(Object, Object) Equals(Object, Object) Equals(Object, Object)

判斷指定的物件執行個體是否視為相等。Determines whether the specified object instances are considered equal.

Finalize() Finalize() Finalize() Finalize()

允許物件在記憶體回收進行回收之前,嘗試釋放資源並執行其他清除作業。Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.

GetHashCode() GetHashCode() GetHashCode() GetHashCode()

做為預設雜湊函式。Serves as the default hash function.

GetType() GetType() GetType() GetType()

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

MemberwiseClone() MemberwiseClone() MemberwiseClone() MemberwiseClone()

建立目前 Object 的淺層複本 (Shallow Copy)。Creates a shallow copy of the current Object.

ReferenceEquals(Object, Object) ReferenceEquals(Object, Object) ReferenceEquals(Object, Object) ReferenceEquals(Object, Object)

判斷指定的 Object 執行個體是否為相同的執行個體。Determines whether the specified Object instances are the same instance.

ToString() ToString() ToString() ToString()

傳回代表目前物件的字串。Returns a string that represents the current object.

適用於

執行緒安全性

公用靜態 (Shared Visual Basic 中) 的這種類型的成員都是安全執行緒。Public static (Shared in Visual Basic) members of this type are thread safe. 不保證執行個體成員是安全執行緒。Instance members are not guaranteed to be thread-safe.