DynamicObject 類別

定義

提供基底類別,以便指定在執行階段時的動態行為。Provides a base class for specifying dynamic behavior at run time. 這個類別必須是繼承類別,您無法直接將其執行個體化。This class must be inherited from; you cannot instantiate it directly.

public ref class DynamicObject : System::Dynamic::IDynamicMetaObjectProvider
[System.Serializable]
public class DynamicObject : System.Dynamic.IDynamicMetaObjectProvider
type DynamicObject = class
    interface IDynamicMetaObjectProvider
Public Class DynamicObject
Implements IDynamicMetaObjectProvider
繼承
DynamicObject
衍生
屬性
實作

範例

假設您想要提供替代語法來存取字典中的值,如此一來,您就可以撰寫 sampleDictionary.Text = "Sample text",而不是撰寫 sampleDictionary["Text"] = "Sample text" (在 Visual Basic 中sampleDictionary("Text") = "Sample text")。Assume that you want to provide alternative syntax for accessing values in a dictionary, so that instead of writing sampleDictionary["Text"] = "Sample text" (sampleDictionary("Text") = "Sample text" in Visual Basic), you can write sampleDictionary.Text = "Sample text". 此外,您想要讓此語法不區分大小寫,因此 sampleDictionary.Text 等同于 sampleDictionary.textAlso, you want this syntax to be case-insensitive, so that sampleDictionary.Text is equivalent to sampleDictionary.text.

下列程式碼範例示範衍生自 DynamicObject 類別的 DynamicDictionary 類別。The following code example demonstrates the DynamicDictionary class, which is derived from the DynamicObject class. DynamicDictionary 類別包含 Dictionary<string, object> 類型(在 Visual Basic 中Dictionary(Of String, Object))的物件,用來儲存索引鍵/值組,並覆寫 TrySetMemberTryGetMember 方法以支援新的語法。The DynamicDictionary class contains an object of the Dictionary<string, object> type (Dictionary(Of String, Object) in Visual Basic) to store the key-value pairs, and overrides the TrySetMember and TryGetMember methods to support the new syntax. 它也會提供 Count 屬性,其中會顯示字典包含多少動態屬性。It also provides a Count property, which shows how many dynamic properties the dictionary contains.

// The class derived from DynamicObject.
public class DynamicDictionary : DynamicObject
{
    // The inner dictionary.
    Dictionary<string, object> dictionary
        = new Dictionary<string, object>();

    // This property returns the number of elements
    // in the inner dictionary.
    public int Count
    {
        get
        {
            return dictionary.Count;
        }
    }

    // If you try to get a value of a property 
    // not defined in the class, this method is called.
    public override bool TryGetMember(
        GetMemberBinder binder, out object result)
    {
        // Converting the property name to lowercase
        // so that property names become case-insensitive.
        string name = binder.Name.ToLower();

        // If the property name is found in a dictionary,
        // set the result parameter to the property value and return true.
        // Otherwise, return false.
        return dictionary.TryGetValue(name, out result);
    }

    // If you try to set a value of a property that is
    // not defined in the class, this method is called.
    public override bool TrySetMember(
        SetMemberBinder binder, object value)
    {
        // Converting the property name to lowercase
        // so that property names become case-insensitive.
        dictionary[binder.Name.ToLower()] = value;

        // You can always add a value to a dictionary,
        // so this method always returns true.
        return true;
    }
}

class Program
{
    static void Main(string[] args)
    {
        // Creating a dynamic dictionary.
        dynamic person = new DynamicDictionary();

        // Adding new dynamic properties. 
        // The TrySetMember method is called.
        person.FirstName = "Ellen";
        person.LastName = "Adams";

        // Getting values of the dynamic properties.
        // The TryGetMember method is called.
        // Note that property names are case-insensitive.
        Console.WriteLine(person.firstname + " " + person.lastname);

        // Getting the value of the Count property.
        // The TryGetMember is not called, 
        // because the property is defined in the class.
        Console.WriteLine(
            "Number of dynamic properties:" + person.Count);

        // The following statement throws an exception at run time.
        // There is no "address" property,
        // so the TryGetMember method returns false and this causes a
        // RuntimeBinderException.
        // Console.WriteLine(person.address);
    }
}

// This example has the following output:
// Ellen Adams
// Number of dynamic properties: 2
' The class derived from DynamicObject.
Public Class DynamicDictionary
    Inherits DynamicObject

    ' The inner dictionary.
    Dim dictionary As New Dictionary(Of String, Object)

    ' This property returns the number of elements
    ' in the inner dictionary.
    ReadOnly Property Count As Integer
        Get
            Return dictionary.Count
        End Get
    End Property


    ' If you try to get a value of a property that is
    ' not defined in the class, this method is called.

    Public Overrides Function TryGetMember(
        ByVal binder As System.Dynamic.GetMemberBinder,
        ByRef result As Object) As Boolean

        ' Converting the property name to lowercase
        ' so that property names become case-insensitive.
        Dim name As String = binder.Name.ToLower()

        ' If the property name is found in a dictionary,
        ' set the result parameter to the property value and return true.
        ' Otherwise, return false.
        Return dictionary.TryGetValue(name, result)
    End Function

    Public Overrides Function TrySetMember(
        ByVal binder As System.Dynamic.SetMemberBinder,
        ByVal value As Object) As Boolean

        ' Converting the property name to lowercase
        ' so that property names become case-insensitive.
        dictionary(binder.Name.ToLower()) = value

        ' You can always add a value to a dictionary,
        ' so this method always returns true.
        Return True
    End Function
End Class

Sub Main()
    ' Creating a dynamic dictionary.
    Dim person As Object = New DynamicDictionary()

    ' Adding new dynamic properties.
    ' The TrySetMember method is called.
    person.FirstName = "Ellen"
    person.LastName = "Adams"

    ' Getting values of the dynamic properties.
    ' The TryGetMember method is called.
    ' Note that property names are now case-insensitive,
    ' although they are case-sensitive in C#.
    Console.WriteLine(person.firstname & " " & person.lastname)

    ' Getting the value of the Count property.
    ' The TryGetMember is not called, 
    ' because the property is defined in the class.
    Console.WriteLine("Number of dynamic properties:" & person.Count)

    ' The following statement throws an exception at run time.
    ' There is no "address" property,
    ' so the TryGetMember method returns false and this causes
    ' a MissingMemberException.
    ' Console.WriteLine(person.address)
End Sub
' This examples has the following output:
' Ellen Adams
' Number of dynamic properties: 2

如需更多範例,請參閱C#常見問題 blog 上的使用 DynamicObject 建立包裝函式。For more examples, see Creating Wrappers with DynamicObject on the C# Frequently Asked Questions blog.

備註

[DynamicObject] 類別可讓您定義可以對動態物件執行哪些作業,以及如何執行這些作業。The DynamicObject class enables you to define which operations can be performed on dynamic objects and how to perform those operations. 例如,您可以定義當您嘗試取得或設定物件屬性、呼叫方法,或執行加法和乘法等標準數學運算時,會發生什麼事。For example, you can define what happens when you try to get or set an object property, call a method, or perform standard mathematical operations such as addition and multiplication.

如果您想要為程式庫建立更方便的通訊協定,這個類別會很有用。This class can be useful if you want to create a more convenient protocol for a library. 例如,如果您的程式庫使用者必須使用類似 Scriptobj.SetProperty("Count", 1)的語法,您可以提供使用更簡單語法的功能,例如 scriptobj.Count = 1For example, if users of your library have to use syntax like Scriptobj.SetProperty("Count", 1), you can provide the ability to use much simpler syntax, like scriptobj.Count = 1.

您無法直接建立 DynamicObject 類別的實例。You cannot directly create an instance of the DynamicObject class. 若要執行動態行為,您可能會想要繼承自 DynamicObject 類別,並覆寫必要的方法。To implement the dynamic behavior, you may want to inherit from the DynamicObject class and override necessary methods. 例如,如果您只需要設定和取得屬性的作業,您可以只覆寫 TrySetMemberTryGetMember 方法。For example, if you need only operations for setting and getting properties, you can override just the TrySetMember and TryGetMember methods.

在C#中,若要為衍生自 DynamicObject 類別的類別實例啟用動態行為,您必須使用 dynamic 關鍵字。In C#, to enable dynamic behavior for instances of classes derived from the DynamicObject class, you must use the dynamic keyword. 如需詳細資訊,請參閱使用動態類型For more information, see Using Type dynamic.

在 Visual Basic 中,晚期繫結支援動態作業。In Visual Basic, dynamic operations are supported by late binding. 如需詳細資訊,請參閱早期和晚期繫結For more information, see Early and Late Binding.

下列程式碼範例示範如何建立衍生自 DynamicObject 類別之類別的實例。The following code example demonstrates how to create an instance of a class that is derived from the DynamicObject class.

public class SampleDynamicObject : DynamicObject {}  
//...  
dynamic sampleObject = new SampleDynamicObject ();  
Public Class SampleDynamicObject   
    Inherits DynamicObject  
'...  
Dim sampleObject As Object = New SampleDynamicObject()  

您也可以將自己的成員新增至衍生自 DynamicObject 類別的類別。You can also add your own members to classes derived from the DynamicObject class. 如果您的類別定義屬性,同時也會覆寫 TrySetMember 方法,則動態語言執行時間(DLR)會先使用語言系結器來尋找類別中屬性的靜態定義。If your class defines properties and also overrides the TrySetMember method, the dynamic language runtime (DLR) first uses the language binder to look for a static definition of a property in the class. 如果沒有這類屬性,DLR 會呼叫 TrySetMember 方法。If there is no such property, the DLR calls the TrySetMember method.

DynamicObject 類別會執行 DLR 介面 IDynamicMetaObjectProvider,讓您能夠在支援 DLR 互通性模型的語言之間共用 DynamicObject 類別的實例。The DynamicObject class implements the DLR interface IDynamicMetaObjectProvider, which enables you to share instances of the DynamicObject class between languages that support the DLR interoperability model. 例如,您可以在中C#建立 DynamicObject 類別的實例,然後將它傳遞至 IronPython 函數。For example, you can create an instance of the DynamicObject class in C# and then pass it to an IronPython function. 如需詳細資訊,請參閱動態語言執行時間總覽For more information, see Dynamic Language Runtime Overview.

注意

如果您有一個簡單的案例,就是您需要只能在執行時間加入和移除成員,但不需要定義特定作業,而且沒有靜態成員的物件,請使用 ExpandoObject 類別。If you have a simple scenario in which you need an object that can only add and remove members at run time but that does not need to define specific operations and does not have static members, use the ExpandoObject class.

如果您有更先進的案例,您需要定義動態物件如何參與互通性通訊協定,或者您需要管理 DLR 快速動態分派快取,請建立您自己的 IDynamicMetaObjectProvider 介面的執行。If you have a more advanced scenario in which you need to define how dynamic objects participate in the interoperability protocol, or you need to manage DLR fast dynamic dispatch caching, create your own implementation of the IDynamicMetaObjectProvider interface.

建構函式

DynamicObject()

讓衍生型別得以初始化 DynamicObject 型別的新執行個體。Enables derived types to initialize a new instance of the DynamicObject type.

方法

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.

(繼承來源 Object)
GetDynamicMemberNames()

傳回所有動態成員名稱的列舉型別。Returns the enumeration of all dynamic member names.

GetHashCode()

作為預設雜湊函數。Serves as the default hash function.

(繼承來源 Object)
GetMetaObject(Expression)

提供分派給動態虛擬方法的 DynamicMetaObjectProvides a DynamicMetaObject that dispatches to the dynamic virtual methods. 此物件可以封裝在另一個 DynamicMetaObject 內部,以提供個別動作的自訂行為。The object can be encapsulated inside another DynamicMetaObject to provide custom behavior for individual actions. 這個方法支援語言實作者適用的動態語言執行階段基礎結構,但不建議直接在程式碼中使用。This method supports the Dynamic Language Runtime infrastructure for language implementers and it is not intended to be used directly from your code.

GetType()

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

(繼承來源 Object)
MemberwiseClone()

建立目前 Object 的淺層複製。Creates a shallow copy of the current Object.

(繼承來源 Object)
ToString()

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

(繼承來源 Object)
TryBinaryOperation(BinaryOperationBinder, Object, Object)

提供二進位運算的實作。Provides implementation for binary operations. 衍生自 DynamicObject 類別的類別可以覆寫這個方法,以指定加法和乘法這類運算的動態行為。Classes derived from the DynamicObject class can override this method to specify dynamic behavior for operations such as addition and multiplication.

TryConvert(ConvertBinder, Object)

提供型別轉換作業的實作。Provides implementation for type conversion operations. 衍生自 DynamicObject 類別的類別可以覆寫這個方法,以指定物件型別轉換作業的動態行為。Classes derived from the DynamicObject class can override this method to specify dynamic behavior for operations that convert an object from one type to another.

TryCreateInstance(CreateInstanceBinder, Object[], Object)

提供作業的實作,這些作業會初始化動態物件的新執行個體。Provides the implementation for operations that initialize a new instance of a dynamic object. 這個方法並不適用於 C# 或 Visual Basic。This method is not intended for use in C# or Visual Basic.

TryDeleteIndex(DeleteIndexBinder, Object[])

提供依索引刪除物件之作業的實作。Provides the implementation for operations that delete an object by index. 這個方法並不適用於 C# 或 Visual Basic。This method is not intended for use in C# or Visual Basic.

TryDeleteMember(DeleteMemberBinder)

提供刪除物件成員之作業的實作。Provides the implementation for operations that delete an object member. 這個方法並不適用於 C# 或 Visual Basic。This method is not intended for use in C# or Visual Basic.

TryGetIndex(GetIndexBinder, Object[], Object)

提供依索引取得值之作業的實作。Provides the implementation for operations that get a value by index. 衍生自 DynamicObject 類別的類別可以覆寫這個方法,以指定索引作業的動態行為。Classes derived from the DynamicObject class can override this method to specify dynamic behavior for indexing operations.

TryGetMember(GetMemberBinder, Object)

提供取得成員值之作業的實作。Provides the implementation for operations that get member values. 衍生自 DynamicObject 類別的類別可以覆寫這個方法,以指定取得屬性值這類作業的動態行為。Classes derived from the DynamicObject class can override this method to specify dynamic behavior for operations such as getting a value for a property.

TryInvoke(InvokeBinder, Object[], Object)

提供叫用物件之作業的實作。Provides the implementation for operations that invoke an object. 衍生自 DynamicObject 類別的類別可以覆寫這個方法,以指定叫用物件或委派這類作業的動態行為。Classes derived from the DynamicObject class can override this method to specify dynamic behavior for operations such as invoking an object or a delegate.

TryInvokeMember(InvokeMemberBinder, Object[], Object)

提供叫用成員之作業的實作。Provides the implementation for operations that invoke a member. 衍生自 DynamicObject 類別的類別可以覆寫這個方法,以指定呼叫方法這類作業的動態行為。Classes derived from the DynamicObject class can override this method to specify dynamic behavior for operations such as calling a method.

TrySetIndex(SetIndexBinder, Object[], Object)

提供依索引設定值之作業的實作。Provides the implementation for operations that set a value by index. 衍生自 DynamicObject 類別的類別可以覆寫這個方法,以指定依指定之索引存取物件之作業的動態行為。Classes derived from the DynamicObject class can override this method to specify dynamic behavior for operations that access objects by a specified index.

TrySetMember(SetMemberBinder, Object)

提供設定成員值之作業的實作。Provides the implementation for operations that set member values. 衍生自 DynamicObject 類別的類別可以覆寫這個方法,以指定設定屬性值這類作業的動態行為。Classes derived from the DynamicObject class can override this method to specify dynamic behavior for operations such as setting a value for a property.

TryUnaryOperation(UnaryOperationBinder, Object)

提供一元運算的實作。Provides implementation for unary operations. 衍生自 DynamicObject 類別的類別可以覆寫這個方法,以指定負號、遞增或遞減這類運算的動態行為。Classes derived from the DynamicObject class can override this method to specify dynamic behavior for operations such as negation, increment, or decrement.

適用於