StreamingContext.Context StreamingContext.Context StreamingContext.Context StreamingContext.Context Property

定义

获取指定为附加上下文的一部分的上下文。Gets context specified as part of the additional context.

public:
 property System::Object ^ Context { System::Object ^ get(); };
public object Context { get; }
member this.Context : obj
Public ReadOnly Property Context As Object

属性值

指定为附加上下文一部分的上下文。The context specified as part of the additional context.

示例

下面的示例创建的实例StreamingContext类使用stateadditional参数。The following example creates an instance of the StreamingContext class using the state and additional parameters. 此代码还显示对象和检索的值的反序列化Context属性。The code also shows the deserialization of an object and retrieving the value of the Context property.

using System;
using System.Text;
using System.Runtime.Serialization.Formatters.Binary;
using System.Runtime.Serialization;
using System.IO;
using System.Security.Permissions;

namespace StreamingContextExample
{
    class Program
    {
        static void Main(string[] args)
        {
            try
            {
                SerializeAndDeserialize();
            }
            catch (System.Exception exc)
            {
                Console.WriteLine(exc.Message);
            }
            finally
            {
                Console.WriteLine("Press <Enter> to exit....");
                Console.ReadLine();
            }
        }
        static void SerializeAndDeserialize()
        {
            object myObject = DateTime.Now;
            // Create a StreamingContext that includes a
            // a DateTime. 
            StreamingContext sc = new StreamingContext(
                StreamingContextStates.CrossProcess, myObject);
            BinaryFormatter bf = new BinaryFormatter(null, sc);
            MemoryStream ms = new MemoryStream(new byte[2048]);
            bf.Serialize(ms, new MyClass());
            ms.Seek(0, SeekOrigin.Begin);
            MyClass f = (MyClass)bf.Deserialize(ms);
            Console.WriteLine("\t MinValue: {0} \n\t MaxValue: {1}", 
                f.MinValue , f.MaxValue);
            Console.WriteLine("StreamingContext.State: {0}", 
                sc.State);

            DateTime myDateTime = (DateTime)sc.Context;
            Console.WriteLine("StreamingContext.Context: {0}",
                myDateTime.ToLongTimeString());
        }
    }

    [Serializable]
    [SecurityPermission(SecurityAction.Demand, SerializationFormatter = true)]
    class MyClass : ISerializable
    {
        private int minValue_value;
        private int maxValue_value;

        public MyClass()
        {
            minValue_value = int.MinValue;
            maxValue_value = int.MaxValue;
        }

        public int MinValue
        {
            get { return minValue_value; }
            set { minValue_value = value;}
        }

        public int MaxValue
        {
            get { return maxValue_value; }
            set { maxValue_value = value; }
        }

        void ISerializable.GetObjectData(SerializationInfo si, StreamingContext context)
        {
            si.AddValue("minValue", minValue_value);
            si.AddValue("maxValue", maxValue_value);
        }

        protected MyClass(SerializationInfo si, StreamingContext context)
        {
            minValue_value = (int)si.GetValue("minValue", typeof(int));
            maxValue_value = (int)si.GetValue("maxValue", typeof(int));            
        }
    }
}
Imports System
Imports System.Text
Imports System.Runtime.Serialization.Formatters.Binary
Imports System.Runtime.Serialization
Imports System.IO
Imports System.Security.Permissions


Class Program
    
    Shared Sub Main(ByVal args() As String) 
        Try
            SerializeAndDeserialize()
        Catch exc As System.Exception
            Console.WriteLine(exc.Message)
        Finally
            Console.WriteLine("Press <Enter> to exit....")
            Console.ReadLine()
        End Try
    
    End Sub 
    
    Shared Sub SerializeAndDeserialize() 
        Dim myObject As Object = DateTime.Now
        ' Create a StreamingContext that includes a
        ' a DateTime. 
        Dim sc As New StreamingContext(StreamingContextStates.CrossProcess, myObject)
        Dim bf As New BinaryFormatter(Nothing, sc)
        Dim ms As New MemoryStream(New Byte(2047) {})
        bf.Serialize(ms, New [MyClass]())
        ms.Seek(0, SeekOrigin.Begin)
        Dim f As [MyClass] = CType(bf.Deserialize(ms), [MyClass])
        Console.WriteLine(vbTab + " MinValue: {0} " + vbLf + vbTab + " MaxValue: {1}", f.MinValue, f.MaxValue)
        Console.WriteLine("StreamingContext.State: {0}", sc.State)
        
        Dim myDateTime As DateTime = CType(sc.Context, DateTime)
        Console.WriteLine("StreamingContext.Context: {0}", myDateTime.ToLongTimeString())
    
    End Sub 
End Class 

<Serializable(), SecurityPermission(SecurityAction.Demand, SerializationFormatter := True)>  _
Class [MyClass]
    Implements ISerializable
    Private minValue_value As Integer
    Private maxValue_value As Integer
    
    Public Sub New() 
        minValue_value = Integer.MinValue
        maxValue_value = Integer.MaxValue    
    End Sub     
    
    Public Property MinValue() As Integer 
        Get
            Return minValue_value
        End Get
        Set
            minValue_value = value
        End Set
    End Property 
    
    Public Property MaxValue() As Integer 
        Get
            Return maxValue_value
        End Get
        Set
            maxValue_value = value
        End Set
    End Property
     
    Sub GetObjectData(ByVal si As SerializationInfo, ByVal context As StreamingContext)  Implements ISerializable.GetObjectData
        si.AddValue("minValue", minValue_value)
        si.AddValue("maxValue", maxValue_value)
    
    End Sub   
    
    Protected Sub New(ByVal si As SerializationInfo, ByVal context As StreamingContext) 
        minValue_value = Fix(si.GetValue("minValue", GetType(Integer)))
        maxValue_value = Fix(si.GetValue("maxValue", GetType(Integer)))
    End Sub 
End Class 

注解

可以为 nullCan be null.

适用于

另请参阅