StreamingContextStates 列挙体
この列挙体には、メンバ値のビットごとの組み合わせを可能にする FlagsAttribute 属性が含まれています。
名前空間: System.Runtime.Serializationアセンブリ: mscorlib (mscorlib.dll 内)

<SerializableAttribute> _ <FlagsAttribute> _ <ComVisibleAttribute(True)> _ Public Enumeration StreamingContextStates
[SerializableAttribute] [FlagsAttribute] [ComVisibleAttribute(true)] public enum StreamingContextStates
[SerializableAttribute] [FlagsAttribute] [ComVisibleAttribute(true)] public enum class StreamingContextStates

メンバ名 | 説明 | |
---|---|---|
All | シリアル化データが、ほかの任意のコンテキストから送信または受信できることを指定します。 | |
Clone | オブジェクト グラフのクローンを作成することを指定します。クローンが作成されたグラフは、同じプロセス内で存在し続け、ハンドルまたはその他のアンマネージ リソースへの参照に安全にアクセスできることをユーザーは想定できます。 | |
CrossAppDomain | 転送元のコンテキストまたは転送先のコンテキストが異なる AppDomain であることを指定します。AppDomain については、「アプリケーション ドメイン」を参照してください。 | |
CrossMachine | 転送元のコンテキストまたは転送先のコンテキストが異なるコンピュータであることを指定します。 | |
CrossProcess | 転送元のコンテキストまたは転送先のコンテキストが、同じコンピュータ上の異なるプロセスであることを指定します。 | |
File | 転送元のコンテキストまたは転送先のコンテキストがファイルであることを指定します。ファイルはファイルを作成したプロセスよりも長く存在し、逆シリアル化で現在のプロセスから任意のデータにアクセスすることを要求するような方法ではオブジェクトがシリアル化されないことをユーザーは想定できます。 | |
Other | シリアル化コンテキストが未確認であることを指定します。 | |
Persistence | 転送元のコンテキストまたは転送先のコンテキストが永続化ストアであることを指定します。永続化ストアには、データベース、ファイル、またはほかのバッキング ストアが含まれます。永続化データはこのデータを作成したプロセスよりも長く存在し、逆シリアル化で現在のプロセスから任意のデータにアクセスすることを要求するような方法ではオブジェクトがシリアル化されないことをユーザーは想定できます。 | |
Remoting | 未確認の場所にあるコンテキストに対してデータがリモート処理されることを指定します。ユーザーは、このデータが同じコンピュータ上にあるかどうかを判断できません。 |

StreamingContextStates 列挙型 (Enum) の使用方法を示すコード例を次に示します。
Imports System Imports System.IO Imports System.Collections Imports System.Runtime.Serialization.Formatters.Binary Imports System.Runtime.Serialization Imports System.Runtime.InteropServices Imports System.Security.Permissions <Assembly: SecurityPermission( _ SecurityAction.RequestMinimum, Execution:=True)> ' This class includes several Win32 interop definitions. Friend Class Win32 Public Shared ReadOnly InvalidHandleValue As New IntPtr(-1) Public Const FILE_MAP_WRITE As Int32 = 2 Public Const PAGE_READWRITE As Int32 = &H4 <DllImport("Kernel32")> _ Public Shared Function CreateFileMapping(ByVal hFile As IntPtr, _ ByVal pAttributes As IntPtr, _ ByVal flProtect As Int32, _ ByVal dwMaximumSizeHigh As Int32, _ ByVal dwMaximumSizeLow As Int32, _ ByVal pName As String) As IntPtr End Function <DllImport("Kernel32")> _ Public Shared Function OpenFileMapping(ByVal dwDesiredAccess As Int32, _ ByVal bInheritHandle As Boolean, _ ByVal name As String) As IntPtr End Function <DllImport("Kernel32")> _ Public Shared Function CloseHandle(ByVal handle As IntPtr) As Boolean End Function <DllImport("Kernel32")> _ Public Shared Function MapViewOfFile(ByVal hFileMappingObject As IntPtr, _ ByVal dwDesiredAccess As Int32, _ ByVal dwFileOffsetHigh As Int32, _ ByVal dwFileOffsetLow As Int32, _ ByVal dwNumberOfBytesToMap As IntPtr) _ As IntPtr End Function <DllImport("Kernel32")> _ Public Shared Function UnmapViewOfFile(ByVal address As IntPtr) As Boolean End Function <DllImport("Kernel32")> _ Public Shared Function DuplicateHandle(ByVal hSourceProcessHandle As IntPtr, _ ByVal hSourceHandle As IntPtr, _ ByVal hTargetProcessHandle As IntPtr, _ ByRef lpTargetHandle As IntPtr, _ ByVal dwDesiredAccess As Int32, _ ByVal bInheritHandle As Boolean, _ ByVal dwOptions As Int32) As Boolean End Function Public Const DUPLICATE_CLOSE_SOURCE As Int32 = &H1 Public Const DUPLICATE_SAME_ACCESS As Int32 = &H2 <DllImport("Kernel32")> Public Shared Function GetCurrentProcess() As IntPtr End Function End Class ' This class wraps memory that can be simultaneously ' shared by multiple AppDomains and Processes. <Serializable()> Public NotInheritable Class SharedMemory Implements ISerializable Implements IDisposable ' The handle and string that identify ' the Windows file-mapping object. Private m_hFileMap As IntPtr = IntPtr.Zero Private m_name As String ' The address of the memory-mapped file-mapping object. Private m_address As IntPtr <SecurityPermissionAttribute(SecurityAction.LinkDemand, _ Flags:=SecurityPermissionFlag.UnmanagedCode)> _ Public Function GetByte(ByVal offset As Int32) As Byte Dim b(0) As Byte Marshal.Copy(New IntPtr(m_address.ToInt64() + offset), b, 0, 1) Return b(0) End Function <SecurityPermissionAttribute(SecurityAction.LinkDemand, _ Flags:=SecurityPermissionFlag.UnmanagedCode)> _ Public Sub SetByte(ByVal offset As Int32, ByVal value As Byte) Dim b(0) As Byte b(0) = value Marshal.Copy(b, 0, New IntPtr(m_address.ToInt64() + offset), 1) End Sub ' The constructors. Public Sub New(ByVal size As Int32) Me.New(size, Nothing) End Sub Public Sub New(ByVal size As Int32, ByVal name As String) m_hFileMap = Win32.CreateFileMapping(Win32.InvalidHandleValue, _ IntPtr.Zero, Win32.PAGE_READWRITE, 0, size, name) If (m_hFileMap.Equals(IntPtr.Zero)) Then _ Throw New Exception("Could not create memory-mapped file.") m_name = name m_address = Win32.MapViewOfFile(m_hFileMap, _ Win32.FILE_MAP_WRITE, 0, 0, IntPtr.Zero) End Sub ' The cleanup methods. Public Sub Dispose() Implements IDisposable.Dispose GC.SuppressFinalize(Me) Dispose(True) End Sub Private Sub Dispose(ByVal disposing As Boolean) Win32.UnmapViewOfFile(m_address) Win32.CloseHandle(m_hFileMap) m_address = IntPtr.Zero m_hFileMap = IntPtr.Zero End Sub Protected Overrides Sub Finalize() Dispose(False) End Sub ' Private helper methods. Private Shared Function AllFlagsSet(ByVal flags As Int32, _ ByVal flagsToTest As Int32) As Boolean Return (flags And flagsToTest) = flagsToTest End Function Private Shared Function AnyFlagsSet(ByVal flags As Int32, _ ByVal flagsToTest As Int32) As Boolean Return (flags And flagsToTest) <> 0 End Function ' The security attribute demands that code that calls ' this method have permission to perform serialization. <SecurityPermissionAttribute(SecurityAction.Demand, SerializationFormatter:=True)> _ Sub GetObjectData(ByVal info As SerializationInfo, _ ByVal context As StreamingContext) _ Implements ISerializable.GetObjectData ' The context's State member indicates where the object will be deserialized. ' A SharedMemory object cannot be serialized ' to any of the following destinations. Const InvalidDestinations As StreamingContextStates = _ StreamingContextStates.CrossMachine Or _ StreamingContextStates.File Or _ StreamingContextStates.Other Or _ StreamingContextStates.Persistence Or _ StreamingContextStates.Remoting If AnyFlagsSet(CType(context.State, Int32), _ CType(InvalidDestinations, Int32)) Then Throw New SerializationException("The SharedMemory object " & _ "cannot be serialized to any of the following streaming contexts: " _ & InvalidDestinations) End If Const DeserializableByHandle As StreamingContextStates = _ StreamingContextStates.Clone Or _ StreamingContextStates.CrossAppDomain If AnyFlagsSet(CType(context.State, Int32), _ CType(DeserializableByHandle, Int32)) Then info.AddValue("hFileMap", m_hFileMap) End If Const DeserializableByName As StreamingContextStates = _ StreamingContextStates.CrossProcess ' The same computer. If AnyFlagsSet(CType(context.State, Int32), CType(DeserializableByName, _ Int32)) Then If m_name = Nothing Then Throw New SerializationException("The SharedMemory object " & _ "cannot be serialized CrossProcess because it was not constructed " & _ "with a String name.") End If info.AddValue("name", m_name) End If End Sub Private Sub New(ByVal info As SerializationInfo, ByVal context As StreamingContext) ' The context's State member indicates where the object was serialized from. Const InvalidSources As StreamingContextStates = _ StreamingContextStates.CrossMachine Or _ StreamingContextStates.File Or _ StreamingContextStates.Other Or _ StreamingContextStates.Persistence Or _ StreamingContextStates.Remoting If AnyFlagsSet(CType(context.State, Int32), CType(InvalidSources, Int32)) Then Throw New SerializationException("The SharedMemory object " & _ "cannot be deserialized from any of the following stream contexts: " & _ InvalidSources) End If Const SerializedByHandle As StreamingContextStates = _ StreamingContextStates.Clone Or _ StreamingContextStates.CrossAppDomain ' The same process. If AnyFlagsSet(CType(context.State, Int32), _ CType(SerializedByHandle, Int32)) Then Try Win32.DuplicateHandle(Win32.GetCurrentProcess(), _ CType(info.GetValue("hFileMap", GetType(IntPtr)), IntPtr), _ Win32.GetCurrentProcess(), m_hFileMap, 0, False, _ Win32.DUPLICATE_SAME_ACCESS) Catch e As SerializationException Throw New SerializationException("A SharedMemory was not " & _ "serialized using any of the following streaming contexts: " & _ SerializedByHandle) End Try End If Const SerializedByName As StreamingContextStates = _ StreamingContextStates.CrossProcess ' The same computer. If AnyFlagsSet(CType(context.State, Int32), _ CType(SerializedByName, Int32)) Then Try m_name = info.GetString("name") Catch e As SerializationException Throw New SerializationException("A SharedMemory object " & _ "was not serialized using any of the following streaming contexts: " & _ SerializedByName) End Try m_hFileMap = Win32.OpenFileMapping(Win32.FILE_MAP_WRITE, False, m_name) End If If Not m_hFileMap.Equals(IntPtr.Zero) Then m_address = Win32.MapViewOfFile(m_hFileMap, _ Win32.FILE_MAP_WRITE, 0, 0, IntPtr.Zero) Else Throw New SerializationException("A SharedMemory object " & _ "could not be deserialized.") End If End Sub End Class Class App <STAThread()> Shared Sub Main() Serialize() Console.WriteLine() Deserialize() End Sub Shared Sub Serialize() ' Create a hashtable of values that will eventually be serialized. Dim sm As New SharedMemory(1024, "MyMemory") Dim x As Int32 For x = 0 To 99 sm.SetByte(x, x) Next Dim b(9) As Byte For x = 0 To b.Length - 1 b(x) = sm.GetByte(x) Next Console.WriteLine(BitConverter.ToString(b)) ' To serialize the hashtable (and its key/value pairs), you must first ' open a stream for writing. Use a file stream here. Dim fs As New FileStream("DataFile.dat", FileMode.Create) ' Construct a BinaryFormatter telling it where ' the objects will be serialized to. Dim formatter As New BinaryFormatter(Nothing, _ New StreamingContext(StreamingContextStates.CrossAppDomain)) Try formatter.Serialize(fs, sm) Catch e As SerializationException Console.WriteLine("Failed to serialize. Reason: " + e.Message) Throw Finally fs.Close() End Try End Sub Shared Sub Deserialize() ' Declare the hashtable reference. Dim sm As SharedMemory = Nothing ' Open the file containing the data that you want to deserialize. Dim fs As New FileStream("DataFile.dat", FileMode.Open) Try Dim Formatter As New BinaryFormatter(Nothing, _ New StreamingContext(StreamingContextStates.CrossAppDomain)) ' Deserialize the SharedMemory object from the file and ' assign the reference to the local variable. sm = DirectCast(Formatter.Deserialize(fs), SharedMemory) Catch e As SerializationException Console.WriteLine("Failed to deserialize. Reason: " & e.Message) Finally fs.Close() End Try ' To prove that the SharedMemory object deserialized correctly, ' display some of its bytes to the console. Dim b(9) As Byte Dim x As Int32 For x = 0 To b.Length - 1 b(x) = sm.GetByte(x) Next Console.WriteLine(BitConverter.ToString(b)) End Sub End Class
// Note: You must compile this file using the C# /unsafe switch. using System; using System.IO; using System.Collections; using System.Runtime.Serialization.Formatters.Binary; using System.Runtime.Serialization; using System.Runtime.InteropServices; using System.Security.Permissions; [assembly: SecurityPermission( SecurityAction.RequestMinimum, Execution = true)] // This class includes several Win32 interop definitions. internal class Win32 { public static readonly IntPtr InvalidHandleValue = new IntPtr(-1); public const UInt32 FILE_MAP_WRITE = 2; public const UInt32 PAGE_READWRITE = 0x04; [DllImport("Kernel32")] public static extern IntPtr CreateFileMapping(IntPtr hFile, IntPtr pAttributes, UInt32 flProtect, UInt32 dwMaximumSizeHigh, UInt32 dwMaximumSizeLow, String pName); [DllImport("Kernel32")] public static extern IntPtr OpenFileMapping(UInt32 dwDesiredAccess, Boolean bInheritHandle, String name); [DllImport("Kernel32")] public static extern Boolean CloseHandle(IntPtr handle); [DllImport("Kernel32")] public static extern IntPtr MapViewOfFile(IntPtr hFileMappingObject, UInt32 dwDesiredAccess, UInt32 dwFileOffsetHigh, UInt32 dwFileOffsetLow, IntPtr dwNumberOfBytesToMap); [DllImport("Kernel32")] public static extern Boolean UnmapViewOfFile(IntPtr address); [DllImport("Kernel32")] public static extern Boolean DuplicateHandle(IntPtr hSourceProcessHandle, IntPtr hSourceHandle, IntPtr hTargetProcessHandle, ref IntPtr lpTargetHandle, UInt32 dwDesiredAccess, Boolean bInheritHandle, UInt32 dwOptions); public const UInt32 DUPLICATE_CLOSE_SOURCE = 0x00000001; public const UInt32 DUPLICATE_SAME_ACCESS = 0x00000002; [DllImport("Kernel32")] public static extern IntPtr GetCurrentProcess(); } // This class wraps memory that can be simultaneously // shared by multiple AppDomains and Processes. [Serializable] public sealed class SharedMemory : ISerializable, IDisposable { // The handle and string that identify // the Windows file-mapping object. private IntPtr m_hFileMap = IntPtr.Zero; private String m_name; // The address of the memory-mapped file-mapping object. private IntPtr m_address; public unsafe Byte* Address { get { return (Byte*)m_address; } } // The constructors. public SharedMemory(Int32 size) : this(size, null) { } public SharedMemory(Int32 size, String name) { m_hFileMap = Win32.CreateFileMapping(Win32.InvalidHandleValue, IntPtr.Zero, Win32.PAGE_READWRITE, 0, unchecked((UInt32)size), name); if (m_hFileMap == IntPtr.Zero) throw new Exception("Could not create memory-mapped file."); m_name = name; m_address = Win32.MapViewOfFile(m_hFileMap, Win32.FILE_MAP_WRITE, 0, 0, IntPtr.Zero); } // The cleanup methods. public void Dispose() { GC.SuppressFinalize(this); Dispose(true); } private void Dispose(Boolean disposing) { Win32.UnmapViewOfFile(m_address); Win32.CloseHandle(m_hFileMap); m_address = IntPtr.Zero; m_hFileMap = IntPtr.Zero; } ~SharedMemory() { Dispose(false); } // Private helper methods. private static Boolean AllFlagsSet(Int32 flags, Int32 flagsToTest) { return (flags & flagsToTest) == flagsToTest; } private static Boolean AnyFlagsSet(Int32 flags, Int32 flagsToTest) { return (flags & flagsToTest) != 0; } // The security attribute demands that code that calls // this method have permission to perform serialization. [SecurityPermissionAttribute(SecurityAction.Demand, SerializationFormatter = true)] void ISerializable.GetObjectData(SerializationInfo info, StreamingContext context) { // The context's State member indicates // where the object will be deserialized. // A SharedMemory object cannot be serialized // to any of the following destinations. const StreamingContextStates InvalidDestinations = StreamingContextStates.CrossMachine | StreamingContextStates.File | StreamingContextStates.Other | StreamingContextStates.Persistence | StreamingContextStates.Remoting; if (AnyFlagsSet((Int32)context.State, (Int32)InvalidDestinations)) throw new SerializationException("The SharedMemory object " + "cannot be serialized to any of the following streaming contexts: " + InvalidDestinations); const StreamingContextStates DeserializableByHandle = StreamingContextStates.Clone | // The same process. StreamingContextStates.CrossAppDomain; if (AnyFlagsSet((Int32)context.State, (Int32)DeserializableByHandle)) info.AddValue("hFileMap", m_hFileMap); const StreamingContextStates DeserializableByName = // The same computer. StreamingContextStates.CrossProcess; if (AnyFlagsSet((Int32)context.State, (Int32)DeserializableByName)) { if (m_name == null) throw new SerializationException("The SharedMemory object " + "cannot be serialized CrossProcess because it was not constructed " + "with a String name."); info.AddValue("name", m_name); } } // The security attribute demands that code that calls // this method have permission to perform serialization. [SecurityPermissionAttribute(SecurityAction.Demand, SerializationFormatter = true)] private SharedMemory(SerializationInfo info, StreamingContext context) { // The context's State member indicates // where the object was serialized from. const StreamingContextStates InvalidSources = StreamingContextStates.CrossMachine | StreamingContextStates.File | StreamingContextStates.Other | StreamingContextStates.Persistence | StreamingContextStates.Remoting; if (AnyFlagsSet((Int32)context.State, (Int32)InvalidSources)) throw new SerializationException("The SharedMemory object " + "cannot be deserialized from any of the following stream contexts: " + InvalidSources); const StreamingContextStates SerializedByHandle = StreamingContextStates.Clone | // The same process. StreamingContextStates.CrossAppDomain; if (AnyFlagsSet((Int32)context.State, (Int32)SerializedByHandle)) { try { Win32.DuplicateHandle(Win32.GetCurrentProcess(), (IntPtr)info.GetValue("hFileMap", typeof(IntPtr)), Win32.GetCurrentProcess(), ref m_hFileMap, 0, false , Win32.DUPLICATE_SAME_ACCESS); } catch (SerializationException) { throw new SerializationException("A SharedMemory was not serialized " + "using any of the following streaming contexts: " + SerializedByHandle); } } const StreamingContextStates SerializedByName = // The same computer. StreamingContextStates.CrossProcess; if (AnyFlagsSet((Int32)context.State, (Int32)SerializedByName)) { try { m_name = info.GetString("name"); } catch (SerializationException) { throw new SerializationException("A SharedMemory object was not " + "serialized using any of the following streaming contexts: " + SerializedByName); } m_hFileMap = Win32.OpenFileMapping(Win32.FILE_MAP_WRITE, false, m_name); } if (m_hFileMap != IntPtr.Zero) { m_address = Win32.MapViewOfFile(m_hFileMap, Win32.FILE_MAP_WRITE, 0, 0, IntPtr.Zero); } else { throw new SerializationException("A SharedMemory object could not " + "be deserialized."); } } } class App { [STAThread] static void Main(string[] args) { Serialize(); Console.WriteLine(); Deserialize(); } unsafe static void Serialize() { // Create a hashtable of values that will eventually be serialized. SharedMemory sm = new SharedMemory(1024, "JeffMemory"); for (Int32 x = 0; x < 100; x++) *(sm.Address + x) = (Byte)x; Byte[] b = new Byte[10]; for (Int32 x = 0; x < b.Length; x++) b[x] = *(sm.Address + x); Console.WriteLine(BitConverter.ToString(b)); // To serialize the SharedMemory object, // you must first open a stream for writing. // Use a file stream here. FileStream fs = new FileStream("DataFile.dat", FileMode.Create); // Construct a BinaryFormatter and tell it where // the objects will be serialized to. BinaryFormatter formatter = new BinaryFormatter(null , new StreamingContext(StreamingContextStates.CrossAppDomain)); try { formatter.Serialize(fs, sm); } catch (SerializationException e) { Console.WriteLine("Failed to serialize. Reason: " + e.Message); throw; } finally { fs.Close(); } } unsafe static void Deserialize() { // Declare a SharedMemory reference. SharedMemory sm = null; // Open the file containing the data that you want to deserialize. FileStream fs = new FileStream("DataFile.dat", FileMode.Open); try { BinaryFormatter formatter = new BinaryFormatter(null , new StreamingContext(StreamingContextStates.CrossAppDomain)); // Deserialize the SharedMemory object from the file and // assign the reference to the local variable. sm = (SharedMemory)formatter.Deserialize(fs); } catch (SerializationException e) { Console.WriteLine("Failed to deserialize. Reason: " + e.Message); throw; } finally { fs.Close(); } // To prove that the SharedMemory object deserialized correctly, // display some of its bytes to the console. Byte[] b = new Byte[10]; for (Int32 x = 0; x < b.Length; x++) b[x] = *(sm.Address + x); Console.WriteLine(BitConverter.ToString(b)); } }

Windows 98, Windows 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
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