Sample Class to Decompress (Unzip) files in Xamarin.Android.

Decompress.cs

using System;
using Android.Util; 
using Java.IO;
using Java.Util.Zip;

namespace ZipManager
{
	public class Decompress
	{
		String _zipFile; 
		String _location; 

		public Decompress(String zipFile, String location)
		{ 
			_zipFile = zipFile; 
			_location = location; 
			DirChecker(""); 
		}

		void DirChecker(String dir)
		{ 
			var file = new File(_location + dir); 

			if(!file.IsDirectory) { 
				file.Mkdirs ();
			} 
		}

		public void UnZip()
		{
			try
			{
				var fileInputStream = new FileInputStream(_zipFile); 
				var zipInputStream = new ZipInputStream(fileInputStream); 
				ZipEntry zipEntry = null; 

				while((zipEntry = zipInputStream.NextEntry)!=null)
				{
					Log.Verbose("Decompress", "UnZipping : "=zipEntry.Name);

					if(zipEntry.IsDirectory)
					{
						DirChecker(zipEntry.Name);
					}
					else
					{
						var fileOutputStream = new FileOutputStream(_location + zipEntry.Name);

						for (int i = zipInputStream.Read(); i != -1; i = zipInputStream.Read())
						{
							fileOutputStream.Write(i);
						}

						zipInputStream.CloseEntry();
						fileOutputStream.Close();
					}
				}
				zipInputStream.Close();
			}
			catch (Exception ex)
			{
				Log.Error ("Decompress", "UnZip", ex);
			}
		}

	}
}

DecompressZipManager.cs

/// <summary>
/// 
///   Sample shows unzipping  'ZipFile.zip'
///   and store in '/sdcard/unzip/'.
/// 
/// </summary>

String zipFile = Android.OS.Environment.ExternalStorageDirectory+"/ZipFile.zip";
String unZipLocation = Android.OS.Environment.ExternalStorageDirectory+"/unzip/";

Decompress decompress = new Decompress (zipFile, unZipLocation);
decompress.UnZip ();