XmlTextWriter.WriteBase64(Byte[], Int32, Int32) Method
Definition
Important
Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.
Encodes the specified binary bytes as base64 and writes out the resulting text.
public:
override void WriteBase64(cli::array <System::Byte> ^ buffer, int index, int count);public override void WriteBase64 (byte[] buffer, int index, int count);override this.WriteBase64 : byte[] * int * int -> unitPublic Overrides Sub WriteBase64 (buffer As Byte(), index As Integer, count As Integer)Parameters
- buffer
- Byte[]
Byte array to encode.
- index
- Int32
The position within the buffer indicating the start of the bytes to write.
- count
- Int32
The number of bytes to write.
Exceptions
buffer is null.
The buffer length minus index is less than count.
index or count is less than zero.
The WriteState is Closed.
Examples
The following example encodes an input file using WriteBase64 and generates a temporary XML file. The temporary XML file is decoded using the ReadBase64 method and compared to the original file.
#using <System.Xml.dll>
using namespace System;
using namespace System::IO;
using namespace System::Xml;
using namespace System::Text;
ref class TestBase64
{
private:
static int bufferSize = 4096;
public:
// Use the WriteBase64 method to create an XML document. The object
// passed by the user is encoded and included in the document.
void EncodeXmlFile( String^ xmlFileName, FileStream^ fileOld )
{
array<Byte>^buffer = gcnew array<Byte>(bufferSize);
int readByte = 0;
XmlTextWriter^ xw = gcnew XmlTextWriter( xmlFileName,Encoding::UTF8 );
xw->WriteStartDocument();
xw->WriteStartElement( "root" );
// Create a Char writer.
BinaryReader^ br = gcnew BinaryReader( fileOld );
// Set the file pointer to the end.
try
{
do
{
readByte = br->Read( buffer, 0, bufferSize );
xw->WriteBase64( buffer, 0, readByte );
}
while ( bufferSize <= readByte );
}
catch ( Exception^ ex )
{
EndOfStreamException^ ex1 = gcnew EndOfStreamException;
if ( ex1->Equals( ex ) )
Console::WriteLine( "We are at end of file" );
else
Console::WriteLine( ex );
}
xw->WriteEndElement();
xw->WriteEndDocument();
xw->Flush();
xw->Close();
}
// Use the ReadBase64 method to decode the new XML document
// and generate the original object.
void DecodeOrignalObject( String^ xmlFileName, FileStream^ fileNew )
{
array<Byte>^buffer = gcnew array<Byte>(bufferSize);
int readByte = 0;
// Create a file to write the bmp back.
BinaryWriter^ bw = gcnew BinaryWriter( fileNew );
XmlTextReader^ tr = gcnew XmlTextReader( xmlFileName );
tr->MoveToContent();
Console::WriteLine( tr->Name );
do
{
readByte = tr->ReadBase64( buffer, 0, bufferSize );
bw->Write( buffer, 0, readByte );
}
while ( readByte >= bufferSize );
bw->Flush();
}
// Compare the two files.
bool CompareResult( FileStream^ fileOld, FileStream^ fileNew )
{
int readByteOld = 0;
int readByteNew = 0;
int count;
int readByte = 0;
array<Byte>^bufferOld = gcnew array<Byte>(bufferSize);
array<Byte>^bufferNew = gcnew array<Byte>(bufferSize);
BinaryReader^ binaryReaderOld = gcnew BinaryReader( fileOld );
BinaryReader^ binaryReaderNew = gcnew BinaryReader( fileNew );
binaryReaderOld->BaseStream->Seek( 0, SeekOrigin::Begin );
binaryReaderNew->BaseStream->Seek( 0, SeekOrigin::Begin );
do
{
readByteOld = binaryReaderOld->Read( bufferOld, 0, bufferSize );
readByteNew = binaryReaderNew->Read( bufferNew, 0, bufferSize );
if ( readByteOld != readByteNew )
return false;
for ( count = 0; count < bufferSize; ++count )
if ( bufferOld[ count ] != bufferNew[ count ] )
return false;
}
while ( count < readByte );
return true;
}
// Display the usage statement.
void Usage()
{
Console::WriteLine( "TestBase64 sourceFile, targetFile \n" );
Console::WriteLine( "For example: TestBase64 winlogon.bmp, target.bmp\n" );
}
};
int main()
{
array<String^>^args = Environment::GetCommandLineArgs();
TestBase64^ testBase64 = gcnew TestBase64;
// Check that the usage is correct.
if ( args->Length < 3 )
{
testBase64->Usage();
return 1;
}
FileStream^ fileOld = gcnew FileStream( args[ 1 ],FileMode::OpenOrCreate,FileAccess::Read,FileShare::Read );
testBase64->EncodeXmlFile( "temp.xml", fileOld );
FileStream^ fileNew = gcnew FileStream( args[ 2 ],FileMode::Create,FileAccess::ReadWrite,FileShare::ReadWrite );
testBase64->DecodeOrignalObject( "temp.xml", fileNew );
// Compare the two files.
if ( testBase64->CompareResult( fileOld, fileNew ) )
Console::WriteLine( "The recreated binary file {0} is the same as {1}", args[ 2 ], args[ 1 ] );
else
Console::WriteLine( "The recreated binary file {0} is not the same as {1}", args[ 2 ], args[ 1 ] );
fileOld->Flush();
fileNew->Flush();
fileOld->Close();
fileNew->Close();
return 0;
}
using System;
using System.IO;
using System.Xml;
using System.Text;
public static class TestBase64
{
private const int bufferSize = 4096;
public static void Main(string[] args)
{
// Check that the usage string is correct.
if (args.Length < 2)
{
TestBase64.Usage();
return;
}
var fileOld = new FileStream(args[0], FileMode.OpenOrCreate, FileAccess.Read, FileShare.Read);
TestBase64.EncodeXmlFile("temp.xml", fileOld);
var fileNew = new FileStream(args[1], FileMode.Create, FileAccess.ReadWrite, FileShare.ReadWrite);
TestBase64.DecodeOrignalObject("temp.xml", fileNew);
// Compare the two files.
if (TestBase64.CompareResult(fileOld, fileNew))
{
Console.WriteLine($"The recreated binary file {args[1]} is the same as {args[0]}");
}
else
{
Console.WriteLine($"The recreated binary file {args[1]} is not the same as {args[0]}");
}
fileOld.Flush();
fileNew.Flush();
fileOld.Close();
fileNew.Close();
}
// Use the WriteBase64 method to create an XML document. The object
// passed by the user is encoded and included in the document.
public static void EncodeXmlFile(string xmlFileName, FileStream fileOld)
{
var buffer = new byte[bufferSize];
int readByte = 0;
var xw = new XmlTextWriter(xmlFileName, Encoding.UTF8);
xw.WriteStartDocument();
xw.WriteStartElement("root");
// Create a Char writer.
var br = new BinaryReader(fileOld);
// Set the file pointer to the end.
try
{
do
{
readByte = br.Read(buffer, 0, bufferSize);
xw.WriteBase64(buffer, 0, readByte);
} while (bufferSize <= readByte);
}
catch (Exception ex)
{
var ex1 = new EndOfStreamException();
if (ex1.Equals(ex))
{
Console.WriteLine("We are at end of file");
}
else
{
Console.WriteLine(ex);
}
}
xw.WriteEndElement();
xw.WriteEndDocument();
xw.Flush();
xw.Close();
}
// Use the ReadBase64 method to decode the new XML document
// and generate the original object.
public static void DecodeOrignalObject(string xmlFileName, FileStream fileNew)
{
var buffer = new byte[bufferSize];
int readByte = 0;
// Create a file to write the bmp back.
var bw = new BinaryWriter(fileNew);
var tr = new XmlTextReader(xmlFileName);
tr.MoveToContent();
Console.WriteLine(tr.Name);
do
{
readByte=tr.ReadBase64(buffer, 0, bufferSize);
bw.Write(buffer, 0, readByte);
} while(readByte >= bufferSize);
bw.Flush();
}
// Compare the two files.
public static bool CompareResult(FileStream fileOld, FileStream fileNew) {
int readByteOld = 0;
int readByteNew = 0;
int count, readByte =0 ;
var bufferOld = new byte[bufferSize];
var bufferNew = new byte[bufferSize];
var binaryReaderOld = new BinaryReader(fileOld);
var binaryReaderNew = new BinaryReader(fileNew);
binaryReaderOld.BaseStream.Seek(0, SeekOrigin.Begin);
binaryReaderNew.BaseStream.Seek(0, SeekOrigin.Begin);
do
{
readByteOld = binaryReaderOld.Read(bufferOld, 0, bufferSize);
readByteNew = binaryReaderNew.Read(bufferNew, 0, bufferSize);
if (readByteOld != readByteNew)
{
return false;
}
for (count = 0; count < bufferSize; count++)
{
if (bufferOld[count] != bufferNew[count])
{
return false;
}
}
} while (count < readByte);
return true;
}
// Display the usage statement.
public static void Usage()
{
Console.WriteLine("TestBase64 sourceFile, targetFile \n");
Console.WriteLine("For example: TestBase64 winlogon.bmp, target.bmp\n");
}
}
Imports System.IO
Imports System.Xml
Imports System.Text
Public Module TestBase64
Private Const bufferSize As Integer = 4096
Public Sub Main()
Dim args As String() = System.Environment.GetCommandLineArgs()
' Check that the usage string is correct.
If args.Length < 3
TestBase64.Usage()
Return
End If
Dim fileOld As New FileStream(args(1), FileMode.OpenOrCreate, FileAccess.Read, FileShare.Read)
TestBase64.EncodeXmlFile("temp.xml", fileOld)
Dim fileNew As New FileStream(args(2), FileMode.Create, FileAccess.ReadWrite, FileShare.ReadWrite)
TestBase64.DecodeOrignalObject("temp.xml", fileNew)
' Compare the two files.
If TestBase64.CompareResult(fileOld, fileNew)
Console.WriteLine($"The recreated binary file {args(2)} is the same as {args(1)}")
Else
Console.WriteLine($"The recreated binary file {args(2)} is not the same as {args(1)}")
End If
fileOld.Flush()
fileNew.Flush()
fileOld.Close()
fileNew.Close()
End Sub
' Use the WriteBase64 method to create an XML document. The object
' passed by the user is encoded and included in the document.
Public Sub EncodeXmlFile(xmlFileName As String, fileOld As FileStream)
Dim buffer(bufferSize - 1) As Byte
Dim readByte As Integer = 0
Dim xw As New XmlTextWriter(xmlFileName, Encoding.UTF8)
xw.WriteStartDocument()
xw.WriteStartElement("root")
' Create a Char writer.
Dim br As New BinaryReader(fileOld)
' Set the file pointer to the end.
Try
Do
readByte = br.Read(buffer, 0, bufferSize)
xw.WriteBase64(buffer, 0, readByte)
Loop While (bufferSize <= readByte)
Catch ex As Exception
Dim ex1 As New EndOfStreamException()
If (ex1.Equals(ex))
Console.WriteLine("We are at end of file")
Else
Console.WriteLine(ex)
End If
End Try
xw.WriteEndElement()
xw.WriteEndDocument()
xw.Flush()
xw.Close()
End Sub
' Use the ReadBase64 method to decode the new XML document
' and generate the original object.
Public Sub DecodeOrignalObject(xmlFileName As String, fileNew As FileStream)
Dim buffer(bufferSize - 1) As Byte
Dim readByte As Integer = 0
' Create a file to write the bmp back.
Dim bw As New BinaryWriter(fileNew)
Dim tr As New XmlTextReader(xmlFileName)
tr.MoveToContent()
Console.WriteLine(tr.Name)
Do
readByte = tr.ReadBase64(buffer, 0, bufferSize)
bw.Write(buffer, 0, readByte)
Loop While (readByte >= bufferSize)
bw.Flush()
End Sub
' Compare the two files.
Public Function CompareResult(fileOld As FileStream, fileNew As FileStream) As Boolean
Dim readByteOld As Integer = 0
Dim readByteNew As Integer = 0
Dim count As Integer
Dim readByte as integer = 0
Dim bufferOld(bufferSize - 1) As Byte
Dim bufferNew(bufferSize - 1) As Byte
Dim binaryReaderOld As New BinaryReader(fileOld)
Dim binaryReaderNew As New BinaryReader(fileNew)
binaryReaderOld.BaseStream.Seek(0, SeekOrigin.Begin)
binaryReaderNew.BaseStream.Seek(0, SeekOrigin.Begin)
Do
readByteOld = binaryReaderOld.Read(bufferOld, 0, bufferSize)
readByteNew = binaryReaderNew.Read(bufferNew, 0, bufferSize)
If readByteOld <> readByteNew
Return False
End If
For count = 0 To bufferSize - 1
If bufferOld(count) <> bufferNew(count)
Return False
End If
Next
Loop While (count < readByte)
Return True
End Function
' Display the usage statement.
Public Sub Usage()
Console.WriteLine("TestBase64 sourceFile, targetFile")
Console.WriteLine("For example: TestBase64 winlogon.bmp, target.bmp")
End Sub
End Module
Remarks
Note
Starting with the .NET Framework 2.0, we recommend that you create XmlWriter instances by using the XmlWriter.Create method and the XmlWriterSettings class to take advantage of new functionality.
Applies to
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