GZipStream Constructor (stream, mode)

DotNetZip

Ionic Zip Library v1.9.1.6 GZipStream Constructor (stream, mode)

Create a GZipStream using the specified CompressionMode.

Declaration Syntax

Visual Basic

Visual C++

public GZipStream(
	Stream stream,
	CompressionMode mode
)

Public Sub New ( _
	stream As Stream, _
	mode As CompressionMode _
)

public:
GZipStream(
	Stream^ stream, 
	CompressionMode mode
)

Parameters

stream (Stream): The stream which will be read or written.

mode (CompressionMode): Indicates whether the GZipStream will compress or decompress.

Remarks

When mode is CompressionMode.Compress, the GZipStream will use the default compression level.

As noted in the class documentation, the CompressionMode (Compress or Decompress) also establishes the "direction" of the stream. A GZipStream with CompressionMode.Compress works only through Write(). A GZipStream with CompressionMode.Decompress works only through Read().

Examples

This example shows how to use a GZipStream to compress data.

CopyC#

using (System.IO.Stream input = System.IO.File.OpenRead(fileToCompress))
{
    using (var raw = System.IO.File.Create(outputFile))
    {
        using (Stream compressor = new GZipStream(raw, CompressionMode.Compress))
        {
            byte[] buffer = new byte[WORKING_BUFFER_SIZE];
            int n;
            while ((n= input.Read(buffer, 0, buffer.Length)) != 0)
            {
                compressor.Write(buffer, 0, n);
            }
        }
    }
}

CopyVB.NET

Dim outputFile As String = (fileToCompress & ".compressed")
Using input As Stream = File.OpenRead(fileToCompress)
    Using raw As FileStream = File.Create(outputFile)
    Using compressor As Stream = New GZipStream(raw, CompressionMode.Compress)
        Dim buffer As Byte() = New Byte(4096) {}
        Dim n As Integer = -1
        Do While (n <> 0)
            If (n > 0) Then
                compressor.Write(buffer, 0, n)
            End If
            n = input.Read(buffer, 0, buffer.Length)
        Loop
    End Using
    End Using
End Using

Examples

This example shows how to use a GZipStream to uncompress a file.

CopyC#

private void GunZipFile(string filename)
{
    if (!filename.EndsWith(".gz))
        throw new ArgumentException("filename");
    var DecompressedFile = filename.Substring(0,filename.Length-3);
    byte[] working = new byte[WORKING_BUFFER_SIZE];
    int n= 1;
    using (System.IO.Stream input = System.IO.File.OpenRead(filename))
    {
        using (Stream decompressor= new Ionic.Zlib.GZipStream(input, CompressionMode.Decompress, true))
        {
            using (var output = System.IO.File.Create(DecompressedFile))
            {
                while (n !=0)
                {
                    n= decompressor.Read(working, 0, working.Length);
                    if (n > 0)
                    {
                        output.Write(working, 0, n);
                    }
                }
            }
        }
    }
}

CopyVB.NET

Private Sub GunZipFile(ByVal filename as String)
    If Not (filename.EndsWith(".gz)) Then
        Throw New ArgumentException("filename")
    End If
    Dim DecompressedFile as String = filename.Substring(0,filename.Length-3)
    Dim working(WORKING_BUFFER_SIZE) as Byte
    Dim n As Integer = 1
    Using input As Stream = File.OpenRead(filename)
        Using decompressor As Stream = new Ionic.Zlib.GZipStream(input, CompressionMode.Decompress, True)
            Using output As Stream = File.Create(UncompressedFile)
                Do
                    n= decompressor.Read(working, 0, working.Length)
                    If n > 0 Then
                        output.Write(working, 0, n)
                    End IF
                Loop While (n  > 0)
            End Using
        End Using
    End Using
End Sub

Assembly: Ionic.Zip (Module: Ionic.Zip) Version: 1.9.1.8 (1.9.1.8)

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