Write Method (Byte[])

BinaryWriter.Write Method (Byte[])


Writes a byte array to the underlying stream.

Namespace:   System.IO
Assembly:  mscorlib (in mscorlib.dll)

public virtual void Write(
	byte[] buffer


Type: System.Byte[]

A byte array containing the data to write.

Exception Condition

An I/O error occurs.


The stream is closed.


buffer is null.

For a list of common I/O tasks, see Common I/O Tasks.

The following code example shows how to write binary data using memory as a backing store, and then verify that the data was written correctly.

using System;
using System.IO;

class BinaryRW
    static void Main()
        const int arrayLength = 1000;

        // Create random data to write to the stream.
        byte[] dataArray = new byte[arrayLength];
        new Random().NextBytes(dataArray);

        BinaryWriter binWriter = new BinaryWriter(new MemoryStream());

        // Write the data to the stream.
        Console.WriteLine("Writing the data.");

        // Create the reader using the stream from the writer.
        BinaryReader binReader = 
            new BinaryReader(binWriter.BaseStream);

        // Set Position to the beginning of the stream.
        binReader.BaseStream.Position = 0;

        // Read and verify the data.
        byte[] verifyArray = binReader.ReadBytes(arrayLength);
        if(verifyArray.Length != arrayLength)
            Console.WriteLine("Error writing the data.");
        for(int i = 0; i < arrayLength; i++)
            if(verifyArray[i] != dataArray[i])
                Console.WriteLine("Error writing the data.");
        Console.WriteLine("The data was written and verified.");

Universal Windows Platform
Available since 4.5
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
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