FromBase64Transform クラス

.NET Framework クラス ライブラリ リファレンス

FromBase64Transform クラス

base 64 から CryptoStream を変換します。

名前空間: System.Security.Cryptography
アセンブリ: mscorlib (mscorlib.dll 内)
構文

Visual Basic (宣言)

<ComVisibleAttribute(True)> _
Public Class FromBase64Transform
    Implements ICryptoTransform, IDisposable

Visual Basic (使用法)

Dim instance As FromBase64Transform

C#

[ComVisibleAttribute(true)] 
public class FromBase64Transform : ICryptoTransform,
 IDisposable

C++

[ComVisibleAttribute(true)] 
public ref class FromBase64Transform : ICryptoTransform,
 IDisposable

J#

/** @attribute ComVisibleAttribute(true) */ 
public class FromBase64Transform implements
 ICryptoTransform, IDisposable

JScript

ComVisibleAttribute(true) 
public class FromBase64Transform implements
 ICryptoTransform, IDisposable

解説

Base 64 Content-Transfer-Encoding は、任意のビット シーケンスをユーザーが判読できない形式で表します。

使用例

Visual Basic

Imports System
Imports System.IO
Imports System.Security.Cryptography

Namespace ToBase64Transform_Examples
    Class MyMainClass
        Public Shared Sub
 Main()
            'Insert your file names into this method call.
            DecodeFromFile("c:\encoded.txt", "c:\roundtrip.txt")
        End Sub 'Main

        Public Shared Sub
 DecodeFromFile(ByVal inFileName As String,
 ByVal outFileName As String)
            Dim myTransform As New
 FromBase64Transform(FromBase64TransformMode.IgnoreWhiteSpaces)

            Dim myOutputBytes(myTransform.OutputBlockSize - 1)
 As Byte

            'Open the input and output files.
            Dim myInputFile As New
 FileStream(inFileName, FileMode.Open, FileAccess.Read)
            Dim myOutputFile As New
 FileStream(outFileName, FileMode.Create, FileAccess.Write)

            'Retrieve the file contents into a byte array.
            Dim myInputBytes(myInputFile.Length - 1) As
 Byte
            myInputFile.Read(myInputBytes, 0, myInputBytes.Length)

            'Transform the data in chunks the size of InputBlockSize.
            Dim i As Integer
 = 0
            While myInputBytes.Length - i > 4 'myTransform.InputBlockSize
                myTransform.TransformBlock(myInputBytes, i, 4, myOutputBytes, 0)
 'myTransform.InputBlockSize
                i += 4 'myTransform.InputBlockSize
                myOutputFile.Write(myOutputBytes, 0, myTransform.OutputBlockSize)
            End While

            'Transform the final block of data.
            myOutputBytes = myTransform.TransformFinalBlock(myInputBytes, i, myInputBytes.Length
 - i)
            myOutputFile.Write(myOutputBytes, 0, myOutputBytes.Length)

            'Free up any used resources.
            myTransform.Clear()

            myInputFile.Close()
            myOutputFile.Close()
        End Sub 'DecodeFromFile
    End Class 'MyMainClass
End Namespace 'ToBase64Transform_Examples

C#

using System;
using System.IO;
using System.Security.Cryptography;

namespace ToBase64Transform_Examples
{
    class MyMainClass
    {
        public static void
 Main()
        {
            //Insert your file names into this method call.
            DecodeFromFile("c:\\encoded.txt", "c:\\roundtrip.txt");
        }

        public static void
 DecodeFromFile(string inFileName, string
 outFileName)
        {
            FromBase64Transform myTransform = new FromBase64Transform(FromBase64TransformMode.IgnoreWhiteSpaces);

            byte[] myOutputBytes = new byte[myTransform.OutputBlockSize];

            //Open the input and output files.
            FileStream myInputFile = new FileStream(inFileName,
 FileMode.Open, FileAccess.Read);
            FileStream myOutputFile = new FileStream(outFileName,
 FileMode.Create, FileAccess.Write);

            //Retrieve the file contents into a byte array.
            byte[] myInputBytes = new byte[myInputFile.Length];
            myInputFile.Read(myInputBytes, 0, myInputBytes.Length);

            //Transform the data in chunks the size of InputBlockSize.
            int i = 0;
            while(myInputBytes.Length - i > 4/*myTransform.InputBlockSize*/)
            {
                myTransform.TransformBlock(myInputBytes, i, 4/*myTransform.InputBlockSize*/,
 myOutputBytes, 0);
                i += 4/*myTransform.InputBlockSize*/;
                myOutputFile.Write(myOutputBytes, 0, myTransform.OutputBlockSize);
            }
            
            //Transform the final block of data.
            myOutputBytes = myTransform.TransformFinalBlock(myInputBytes, i, myInputBytes.Length
 - i);
            myOutputFile.Write(myOutputBytes, 0, myOutputBytes.Length);

            //Free up any used resources.
            myTransform.Clear();

            myInputFile.Close();
            myOutputFile.Close();
        }
    }
}

C++

using namespace System;
using namespace System::IO;
using namespace System::Security::Cryptography;
class MyMainClass
{
public:
   static void DecodeFromFile( String^ inFileName,
 String^ outFileName )
   {
      FromBase64Transform^ myTransform = gcnew FromBase64Transform( FromBase64TransformMode::IgnoreWhiteSpaces
 );
      array<Byte>^myOutputBytes = gcnew array<Byte>(myTransform->OutputBlockSize);
      
      //Open the input and output files.
      FileStream^ myInputFile = gcnew FileStream( inFileName,FileMode::Open,FileAccess::Read
 );
      FileStream^ myOutputFile = gcnew FileStream( outFileName,FileMode::Create,FileAccess::Write
 );
      
      //Retrieve the file contents into a Byte array.
      array<Byte>^myInputBytes = gcnew array<Byte>(myInputFile->Length);
      myInputFile->Read( myInputBytes, 0, myInputBytes->Length );
      
      //Transform the data in chunks the size of InputBlockSize.
      int i = 0;
      while ( myInputBytes->Length - i > 4 )
      {
         myTransform->TransformBlock( myInputBytes, i, 4, myOutputBytes, 0 );
         
         /*myTransform->InputBlockSize*/
         i += 4;
         
         /*myTransform->InputBlockSize*/
         myOutputFile->Write( myOutputBytes, 0, myTransform->OutputBlockSize
 );
      }

      
      //Transform the final block of data.
      myOutputBytes = myTransform->TransformFinalBlock( myInputBytes, i, myInputBytes->Length
 - i );
      myOutputFile->Write( myOutputBytes, 0, myOutputBytes->Length );
      
      //Free up any used resources.
      myTransform->Clear();
      myInputFile->Close();
      myOutputFile->Close();
   }

};

int main()
{
   MyMainClass * m = new MyMainClass;
   
   //Insert your file names into this method call.
   m->DecodeFromFile(  "c:\\encoded.txt",  "c:\\roundtrip.txt"
 );
}

J#

package ToBase64Transform_Examples; 
import System.*;
import System.IO.*;
import System.Security.Cryptography.*;

class MyMainClass
{
    public static void main(String[]
 args)
    {
        // Insert your file names into this method call.
        DecodeFromFile("c:\\encoded.txt", "c:\\roundtrip.txt");
    } //main

    public static void DecodeFromFile(String
 inFileName, String outFileName)
    {
        FromBase64Transform myTransform = 
            new FromBase64Transform(FromBase64TransformMode.IgnoreWhiteSpaces);
        ubyte myOutputBytes[] = new ubyte[myTransform.get_OutputBlockSize()];

        // Open the input and output files.
        FileStream myInputFile = 
            new FileStream(inFileName, FileMode.Open, FileAccess.Read);
        FileStream myOutputFile = 
            new FileStream(outFileName, FileMode.Create, FileAccess.Write);

        // Retrieve the file contents into a byte array.
        // const int temp = 2;
        ubyte myInputBytes[] = 
            new ubyte[(new Long(myInputFile.get_Length())).intValue()];
        myInputFile.Read(myInputBytes, 0, myInputBytes.length);

        // Transform the data in chunks the size of InputBlockSize.
        int i = 0;
        while (myInputBytes.length - i > 4/*myTransform.InputBlockSize*/)
 {
            myTransform.TransformBlock(myInputBytes, i, 
                4/*myTransform.InputBlockSize*/, myOutputBytes, 0);
            i += 4 /*myTransform.InputBlockSize*/;
            myOutputFile.Write(myOutputBytes, 0, 
                myTransform.get_OutputBlockSize());
        }

        // Transform the final block of data.
        myOutputBytes = myTransform.TransformFinalBlock(myInputBytes, 
            i, myInputBytes.length - i);
        myOutputFile.Write(myOutputBytes, 0, myOutputBytes.length);

        // Free up any used resources.
        myTransform.Clear();
        myInputFile.Close();
        myOutputFile.Close();
    } //DecodeFromFile
} //MyMainClass   

継承階層

System.Object
  System.Security.Cryptography.FromBase64Transform

スレッド セーフ

この型の public static (Visual Basic では Shared) メンバはすべて、スレッド セーフです。インスタンス メンバの場合は、スレッド セーフであるとは限りません。

プラットフォーム

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

開発プラットフォームの中には、.NET Framework によってサポートされていないバージョンがあります。サポートされているバージョンについては、「システム要件」を参照してください。

バージョン情報

.NET Framework
サポート対象 : 2.0、1.1、1.0

参照

関連項目
FromBase64Transform メンバ
System.Security.Cryptography 名前空間
その他の技術情報
暗号サービス