WriteBase64 Método (Byte[], Int32, Int32)
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XmlWriter.WriteBase64 (Método) (Byte[], Int32, Int32)

 

Cuando se invalida en una clase derivada, codifica los bytes binarios especificados en Base64 y escribe el texto resultante.

Espacio de nombres:   System.Xml
Ensamblado:  System.Xml (en System.Xml.dll)

public abstract void WriteBase64(
	byte[] buffer,
	int index,
	int count
)

Parámetros

buffer

Matriz de bytes que se va a codificar.

index

Posición en el búfer que indica el inicio de los bytes que se van a escribir.

count

Número de bytes que se van a escribir.

Exception Condition
ArgumentNullException

buffer is null.

ArgumentOutOfRangeException

index or count is less than zero.

-or-

The buffer length minus index is less than count.

InvalidOperationException

An XmlWriter method was called before a previous asynchronous operation finished.In this case, InvalidOperationException is thrown with the message “An asynchronous operation is already in progress.”

For example, the byte buffer may contain the binary contents of a GIF image.This clearly would not be valid XML.The Base64 encoding is designed to represent arbitrary byte sequences in a text form comprised of the 65 US-ASCII characters ([A-Za-z0-9+/=]) where each character encodes 6 bits of the binary data.For more information, see Requests for Comments (RFC) 1521 located on the Request for Comments Web site at http://www.rfc-editor.org/.

For the asynchronous version of this method, see WriteBase64Async.

The following example uses the WriteBase64 method to write Base64 data.The Base64 data is embedded within an <image> element.


public static void Base64EncodeImageFile() {

  int bufferSize = 1000;
  byte[] buffer = new byte[bufferSize];
  int readBytes = 0;

  using (XmlWriter writer = XmlWriter.Create("output.xml")) {

       FileStream inputFile = new FileStream(@"C:\artFiles\sunset.jpg",
                                                                    FileMode.OpenOrCreate, FileAccess.Read, FileShare.Read);
       writer.WriteStartDocument();
       writer.WriteStartElement("image");
       BinaryReader br = new BinaryReader(inputFile);
       Console.WriteLine("\r\nWriting Base64 data...");

       do {
          readBytes = br.Read(buffer, 0, bufferSize);
          writer.WriteBase64(buffer, 0, readBytes);
       } while (bufferSize <= readBytes);
       br.Close();

    writer.WriteEndElement();// </image>
    writer.WriteEndDocument();

  }
}

Universal Windows Platform
Disponible desde 4.5
.NET Framework
Disponible desde 1.1
Portable Class Library
Compatible con: portable .NET platforms
Silverlight
Disponible desde 2.0
Windows Phone Silverlight
Disponible desde 7.0
Windows Phone
Disponible desde 8.1
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