zipping & unzipping files in C#

Question

Friends, I need to zip & unzip files programmatically in C#. Are there any classes in .NET framework to do this(Like java.util.zip.* in Java)? Any suggestions on how to proceed?

Administrator · Answer

Hi, I don't know about .NET specifically, but this is a port of a VB call to zlib (you can get the zlib library itself from loads of places) using System; using System.IO; using System.Runtime.InteropServices; namespace Compression { /// /// Provides interfaces to Compress/Decompress strings byte arrays /// public class StringCompression { public StringCompression() { // // TODO: Add constructor logic here // } // // Do not need it for just ten byes !!!! // [DllImport("\develop\CompTest\lib\zlib.dll",SetLastError=true)] private static extern int compress2( [MarshalAs(UnmanagedType.LPArray)] byte[] dest, ref int destLen, [MarshalAs(UnmanagedType.LPArray)] byte[] src, int srcLen, int level ); [DllImport("\develop\CompTest\lib\zlib.dll",SetLastError=true)] private static extern int uncompress( [MarshalAs(UnmanagedType.LPArray)] byte[] dest, ref int destLen, [MarshalAs(UnmanagedType.LPArray)] byte[] src, int srcLen ); /// /// C# Implementation of VB ReDim function /// /// /// /// private static byte[] ReDim( byte[] aData, long lLength ) { byte[] aRetVal = new byte[lLength]; for ( long l = 0; l < aData.Length && l < lLength ; l++ ) { aRetVal[l] = aData[l]; } return aRetVal; } public static String DecompressString2ByteArray(byte[] aData) { // // Indexing is a bit different in c#, than it is in VB that is why // we have to add +1 here and there ... // if (aData.Length < 10) return ""; string res; res = ""; try { System.Text.ASCIIEncoding objAsc = new System.Text.ASCIIEncoding(); // // For ten byte memory move, it is not worth // importing and calling another .dll, just do it ! // byte[] aSize = new byte[9+1]; long pos = aData.Length - (9 + 1); for (int i =0; i < 10; i ++) { aSize[i] = aData[pos+i]; } int lSize; lSize = int.Parse (objAsc.GetString(aSize)); byte[] aBuffer = new byte [lSize]; uncompress ( aBuffer, ref lSize,aData, aData.Length -(9+1) ); res = objAsc.GetString(aBuffer); } catch (System.ExecutionEngineException eex ) { String s = eex.StackTrace; res = ""; } catch ( Exception ex ) { String s = ex.StackTrace; res = ""; } finally { } return res; } public static byte[] CompressString2ByteArray(String inpstr) { System.Text.ASCIIEncoding objAsc = new System.Text.ASCIIEncoding(); byte[] aData = objAsc.GetBytes(inpstr); byte[] aCompData = new byte[0]; int lLenght, lBufferSize; lLenght = inpstr.Length; lBufferSize = inpstr.Length; //FileLog( "BufferSize before: " + lBufferSize.ToString() ); lBufferSize = lBufferSize + (int)(lBufferSize * 0.01) + 12; //FileLog( "BufferSize after: " + lBufferSize.ToString() ); // // Indexing is a bit different in c#, than it is in VB that is why // we have to add +1 here and there ... // try { aCompData = new byte[lBufferSize]; compress2 ( aCompData, ref lBufferSize,aData, lLenght, 9 ); string len; len = lLenght.ToString().PadLeft (10,'0'); aCompData = ReDim( aCompData, lBufferSize + (9 + 1)); byte[] aLenght = objAsc.GetBytes(len); // // For ten byte memory move, it is not worth // importing and calling another .dll, just do it ! // long pos = aCompData.Length - (9 + 1); for (int i =0; i < 10; i ++) { aCompData[pos+i] = aLenght [i]; } } catch (System.ExecutionEngineException eex ) { String s = eex.StackTrace; aCompData = null; } catch ( Exception ex ) { String s = ex.StackTrace; aCompData = null; } finally { } //FileLog("Compression result : " + objAsc.GetString( aCompData ) ); return aCompData; } } }

zipping & unzipping files in C#

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