DataContractAttribute 類別

定義

命名空間:: System.Runtime.Serialization

組件:: System.Runtime.Serialization.dll, System.Runtime.Serialization.Primitives.dll

組件:: System.Runtime.Serialization.dll

組件:: netstandard.dll

重要

部分資訊涉及發行前產品，在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊，不做任何明確或隱含的瑕疵擔保。

指定型別會定義或實作資料合約，而且可由串行化程式串行化，例如 DataContractSerializer。若要使其類型可串行化，類型作者必須為其類型定義數據合約。

public ref class DataContractAttribute sealed : Attribute

[System.AttributeUsage(System.AttributeTargets.Class | System.AttributeTargets.Enum | System.AttributeTargets.Struct, AllowMultiple=false, Inherited=false)]
public sealed class DataContractAttribute : Attribute

[<System.AttributeUsage(System.AttributeTargets.Class | System.AttributeTargets.Enum | System.AttributeTargets.Struct, AllowMultiple=false, Inherited=false)>]
type DataContractAttribute = class
    inherit Attribute

Public NotInheritable Class DataContractAttribute
Inherits Attribute

繼承: Object

Attribute
DataContractAttribute

屬性: AttributeUsageAttribute

範例

以下範例序列化與反序列化一個已套用的類別PersonDataContractAttribute。請注意， Namespace 和 Name 屬性的值已設定為覆蓋預設設定的值。

namespace DataContractAttributeExample
{
    // Set the Name and Namespace properties to new values.
    [DataContract(Name = "Customer", Namespace = "http://www.contoso.com")]
    class Person : IExtensibleDataObject
    {
        // To implement the IExtensibleDataObject interface, you must also
        // implement the ExtensionData property.
        private ExtensionDataObject extensionDataObjectValue;
        public ExtensionDataObject ExtensionData
        {
            get
            {
                return extensionDataObjectValue;
            }
            set
            {
                extensionDataObjectValue = value;
            }
        }

        [DataMember(Name = "CustName")]
        internal string Name;

        [DataMember(Name = "CustID")]
        internal int ID;

        public Person(string newName, int newID)
        {
            Name = newName;
            ID = newID;
        }
    }

    class Test
    {
        public static void Main()
        {
            try
            {
                WriteObject("DataContractExample.xml");
                ReadObject("DataContractExample.xml");
                Console.WriteLine("Press Enter to end");
                Console.ReadLine();
            }
            catch (SerializationException se)
            {
                Console.WriteLine
                ("The serialization operation failed. Reason: {0}",
                  se.Message);
                Console.WriteLine(se.Data);
                Console.ReadLine();
            }
        }

        public static void WriteObject(string path)
        {
            // Create a new instance of the Person class and
            // serialize it to an XML file.
            Person p1 = new Person("Mary", 1);
            // Create a new instance of a StreamWriter
            // to read and write the data.
            FileStream fs = new FileStream(path,
            FileMode.Create);
            XmlDictionaryWriter writer = XmlDictionaryWriter.CreateTextWriter(fs);
            DataContractSerializer ser =
                new DataContractSerializer(typeof(Person));
            ser.WriteObject(writer, p1);
            Console.WriteLine("Finished writing object.");
            writer.Close();
            fs.Close();
        }
        public static void ReadObject(string path)
        {
            // Deserialize an instance of the Person class
            // from an XML file. First create an instance of the
            // XmlDictionaryReader.
            FileStream fs = new FileStream(path, FileMode.OpenOrCreate);
            XmlDictionaryReader reader =
                XmlDictionaryReader.CreateTextReader(fs, new XmlDictionaryReaderQuotas());

            // Create the DataContractSerializer instance.
            DataContractSerializer ser =
                new DataContractSerializer(typeof(Person));

            // Deserialize the data and read it from the instance.
            Person newPerson = (Person)ser.ReadObject(reader);
            Console.WriteLine("Reading this object:");
            Console.WriteLine(String.Format("{0}, ID: {1}",
            newPerson.Name, newPerson.ID));
            fs.Close();
        }
    }
}

Namespace DataContractAttributeExample
    ' Set the Name and Namespace properties to new values.
    <DataContract(Name := "Customer", [Namespace] := "http://www.contoso.com")>  _
    Class Person
        Implements IExtensibleDataObject
        ' To implement the IExtensibleDataObject interface, you must also
        ' implement the ExtensionData property.
        Private extensionDataObjectValue As ExtensionDataObject 
        
        Public Property ExtensionData() As ExtensionDataObject _
          Implements IExtensibleDataObject.ExtensionData
            Get
                Return extensionDataObjectValue
            End Get
            Set
                extensionDataObjectValue = value
            End Set
        End Property
        
        <DataMember(Name := "CustName")>  _
        Friend Name As String
        
        <DataMember(Name := "CustID")>  _
        Friend ID As Integer
        
        
        Public Sub New(ByVal newName As String, ByVal newID As Integer) 
            Name = newName
            ID = newID
        
        End Sub 
    End Class 
    
    
    Class Test
        
        Public Shared Sub Main() 
            Try
                WriteObject("DataContractExample.xml")
                ReadObject("DataContractExample.xml")
                Console.WriteLine("Press Enter to end")
                Console.ReadLine()
            Catch se As SerializationException
                Console.WriteLine("The serialization operation failed. Reason: {0}", _
                   se.Message)
                Console.WriteLine(se.Data)
                Console.ReadLine()
            End Try
        
        End Sub 
        
        
        Public Shared Sub WriteObject(ByVal path As String) 
            ' Create a new instance of the Person class and 
            ' serialize it to an XML file.
            Dim p1 As New Person("Mary", 1)
            ' Create a new instance of a StreamWriter
            ' to read and write the data.
            Dim fs As New FileStream(path, FileMode.Create)
            Dim writer As XmlDictionaryWriter = XmlDictionaryWriter.CreateTextWriter(fs)
            Dim ser As New DataContractSerializer(GetType(Person))
            ser.WriteObject(writer, p1)
            Console.WriteLine("Finished writing object.")
            writer.Close()
            fs.Close()
        
        End Sub 
        
        Public Shared Sub ReadObject(ByVal path As String) 
            ' Deserialize an instance of the Person class 
            ' from an XML file. First create an instance of the 
            ' XmlDictionaryReader.
            Dim fs As New FileStream(path, FileMode.OpenOrCreate)
            Dim reader As XmlDictionaryReader = XmlDictionaryReader. _
              CreateTextReader(fs, New XmlDictionaryReaderQuotas())
            
            ' Create the DataContractSerializer instance.
            Dim ser As New DataContractSerializer(GetType(Person))
            
            ' Deserialize the data and read it from the instance.
            Dim newPerson As Person = CType(ser.ReadObject(reader), Person)
            Console.WriteLine("Reading this object:")
            Console.WriteLine(String.Format("{0}, ID: {1}", newPerson.Name, newPerson.ID))
            fs.Close()
        
        End Sub 
    End Class 
End Namespace

備註

欲了解更多關於此 API 的資訊，請參閱 DataContractAttribute 的補充 API 備註。

建構函式

名稱	Description
DataContractAttribute()	初始化 DataContractAttribute 類別的新執行個體。

屬性

名稱	Description
IsNameSetExplicitly	讀取是否 Name 被明確設定。
IsNamespaceSetExplicitly	讀取是否 Namespace 被明確設定。
IsReference	取得或設定值，這個值表示是否要保留物件參考資料。
IsReferenceSetExplicitly	讀取是否 IsReference 被明確設定。
Name	取得或設定該型別的資料合約名稱。
Namespace	取得或設定型別之資料合約的命名空間。
TypeId	在衍生類別中實作時，取得這個 Attribute的唯一標識碼。 (繼承來源 Attribute)

方法

名稱	Description
Equals(Object)	傳回值，這個值表示這個實例是否等於指定的物件。 (繼承來源 Attribute)
GetHashCode()	傳回這個實例的哈希碼。 (繼承來源 Attribute)
GetType()	取得目前實例的 Type。 (繼承來源 Object)
IsDefaultAttribute()	在衍生類別中覆寫時，指出這個實例的值是否為衍生類別的預設值。 (繼承來源 Attribute)
Match(Object)	在衍生類別中覆寫時，傳回值，指出這個實例是否等於指定的物件。 (繼承來源 Attribute)
MemberwiseClone()	建立目前 Object的淺層複本。 (繼承來源 Object)
ToString()	傳回表示目前物件的字串。 (繼承來源 Object)

明確介面實作

名稱	Description
_Attribute.GetIDsOfNames(Guid, IntPtr, UInt32, UInt32, IntPtr)	將一組名稱對應至一組對應的分派識別項 (Dispatch Identifier)。 (繼承來源 Attribute)
_Attribute.GetTypeInfo(UInt32, UInt32, IntPtr)	擷取物件的型別資訊，可用來取得介面的類型資訊。 (繼承來源 Attribute)
_Attribute.GetTypeInfoCount(UInt32)	擷取物件提供的類型資訊介面數目 (0 或 1)。 (繼承來源 Attribute)
_Attribute.Invoke(UInt32, Guid, UInt32, Int16, IntPtr, IntPtr, IntPtr, IntPtr)	提供物件所公開屬性和方法的存取權。 (繼承來源 Attribute)

適用於

另請參閱

意見反應

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