Read Method

DeflateStream.Read Method (Byte[], Int32, Int32)


Reads a number of decompressed bytes into the specified byte array.

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

public override int Read(
	byte[] array,
	int offset,
	int count


Type: System.Byte[]

The array to store decompressed bytes.

Type: System.Int32

The byte offset in array at which the read bytes will be placed.

Type: System.Int32

The maximum number of decompressed bytes to read.

Return Value

Type: System.Int32

The number of bytes that were read into the byte array.

Exception Condition

array is null.


The CompressionMode value was Compress when the object was created.

- or -

The underlying stream does not support reading.


offset or count is less than zero.


array length minus the index starting point is less than count.


The data is in an invalid format.


The stream is closed.

The following example shows how to compress and decompress bytes by using the Read and Write methods.

using System;
using System.Text;
using System.IO;
using System.IO.Compression;

namespace ExampleConsoleApplication
    class Program
        static void Main(string[] args)
            UnicodeEncoding uniEncode = new UnicodeEncoding();

            byte[] bytesToCompress = uniEncode.GetBytes("example text to compress and decompress");
            Console.WriteLine("starting with: " + uniEncode.GetString(bytesToCompress));

            using (FileStream fileToCompress = File.Create("examplefile.gz"))
                using (DeflateStream compressionStream = new DeflateStream(fileToCompress, CompressionMode.Compress))
                    compressionStream.Write(bytesToCompress, 0, bytesToCompress.Length);

            byte[] decompressedBytes = new byte[bytesToCompress.Length];
            using (FileStream fileToDecompress = File.Open("examplefile.gz", FileMode.Open))
                using (DeflateStream decompressionStream = new DeflateStream(fileToDecompress, CompressionMode.Decompress))
                    decompressionStream.Read(decompressedBytes, 0, bytesToCompress.Length);

            Console.WriteLine("ending with: " + uniEncode.GetString(decompressedBytes));

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