Added ImageFileCache, removed TileImageLoader.CreateCache.

Caching/FileDbCache/FileDbCache.cs

@@ -12,7 +12,7 @@ namespace Caching
     /// <summary>
     /// ObjectCache implementation based on EzTools FileDb - http://www.eztools-software.com/tools/filedb/.
     /// </summary>
-    public class FileDbCache : ObjectCache, IDisposable
+    public class FileDbCache : ObjectCache
     {
         private const string keyField = "Key";
         private const string valueField = "Value";
@@ -67,7 +67,7 @@ namespace Caching
             }
 
             this.name = name;
-            path = Path.Combine(directory, name);
+            path = Path.Combine(directory, name.Trim());
 
             if (string.IsNullOrEmpty(Path.GetExtension(path)))
             {
@@ -91,6 +91,11 @@ namespace Caching
             {
                 CreateDatabase();
             }
+
+            if (fileDb.IsOpen)
+            {
+                AppDomain.CurrentDomain.ProcessExit += OnProcessExit;
+            }
         }
 
         public bool AutoFlush
@@ -406,12 +411,45 @@ namespace Caching
             }
         }
 
-        public void Dispose()
+        public void Close()
+        {
+            if (fileDb.IsOpen)
+            {
+                fileDb.Close();
+                AppDomain.CurrentDomain.ProcessExit -= OnProcessExit;
+            }
+        }
+
+        private void OnProcessExit(object sender, EventArgs e)
+        {
+            Close();
+        }
+
+        private void CreateDatabase()
         {
             if (fileDb.IsOpen)
             {
                 fileDb.Close();
             }
+
+            if (File.Exists(path))
+            {
+                File.Delete(path);
+            }
+            else
+            {
+                Directory.CreateDirectory(Path.GetDirectoryName(path));
+            }
+
+            fileDb.Create(path,
+                new Field[]
+            {
+                new Field(keyField, DataTypeEnum.String) { IsPrimaryKey = true },
+                new Field(valueField, DataTypeEnum.Byte) { IsArray = true },
+                new Field(expiresField, DataTypeEnum.DateTime)
+            });
+
+            Trace.TraceInformation("FileDbCache: Created database {0}", path);
         }
 
         private bool RepairDatabase()
@@ -420,47 +458,19 @@ namespace Caching
             {
                 fileDb.Reindex();
             }
-            catch (Exception ex)
+            catch (Exception ex1)
             {
-                Trace.TraceWarning("FileDbCache: FileDb.Reindex() failed: {0}", ex.Message);
+                Trace.TraceWarning("FileDbCache: FileDb.Reindex() failed: {0}", ex1.Message);
-                return CreateDatabase();
-            }
 
-            return true;
+                try
-        }
-
-        private bool CreateDatabase()
-        {
-            if (fileDb.IsOpen)
-            {
-                fileDb.Close();
-            }
-
-            try
-            {
-                if (File.Exists(path))
                 {
-                    File.Delete(path);
+                    CreateDatabase();
                 }
-                else
+                catch (Exception ex2)
                 {
-                    Directory.CreateDirectory(Path.GetDirectoryName(path));
+                    Trace.TraceWarning("FileDbCache: Creating database {0} failed: {1}", path, ex2.Message);
+                    return false;
                 }
-
-                fileDb.Create(path,
-                    new Field[]
-                {
-                    new Field(keyField, DataTypeEnum.String) { IsPrimaryKey = true },
-                    new Field(valueField, DataTypeEnum.Byte) { IsArray = true },
-                    new Field(expiresField, DataTypeEnum.DateTime)
-                });
-
-                Trace.TraceInformation("FileDbCache: Created database {0}", path);
-            }
-            catch (Exception ex)
-            {
-                Trace.TraceWarning("FileDbCache: Creating database failed: {0}", ex.Message);
-                return false;
             }
 
             return true;

Caching/ImageFileCache/ImageFileCache.cs

@@ -0,0 +1,293 @@
+using System;
+using System.Collections.Generic;
+using System.Collections.Specialized;
+using System.Diagnostics;
+using System.IO;
+using System.Linq;
+using System.Runtime.Caching;
+
+namespace Caching
+{
+    /// <summary>
+    /// ObjectCache implementation based on local image files.
+    /// The only valid data type for cached values is a byte[], which contains
+    /// an 8-byte binary UTC time (as created by DateTime.ToBinary), followed
+    /// by a PNG, JPEG, BMP, GIF, TIFF or WMP image buffer.
+    /// </summary>
+    public class ImageFileCache : ObjectCache
+    {
+        private readonly string name;
+        private readonly string directory;
+
+        public ImageFileCache(string name, NameValueCollection config)
+            : this(name, config["directory"])
+        {
+        }
+
+        public ImageFileCache(string name, string directory)
+        {
+            if (string.IsNullOrWhiteSpace(name))
+            {
+                throw new ArgumentException("The parameter name must not be null or empty or only white-space.");
+            }
+
+            if (string.IsNullOrWhiteSpace(directory))
+            {
+                throw new ArgumentException("The parameter directory must not be null or empty or only white-space.");
+            }
+
+            this.name = name;
+            this.directory = Path.Combine(directory, name.Trim());
+            Directory.CreateDirectory(this.directory);
+
+            Trace.TraceInformation("Created ImageFileCache in {0}", this.directory);
+        }
+
+        public override string Name
+        {
+            get { return name; }
+        }
+
+        public override DefaultCacheCapabilities DefaultCacheCapabilities
+        {
+            get { return DefaultCacheCapabilities.InMemoryProvider; }
+        }
+
+        public override object this[string key]
+        {
+            get { return Get(key); }
+            set { Set(key, value, null); }
+        }
+
+        protected override IEnumerator<KeyValuePair<string, object>> GetEnumerator()
+        {
+            throw new NotSupportedException("LocalFileCache does not support the ability to enumerate items.");
+        }
+
+        public override CacheEntryChangeMonitor CreateCacheEntryChangeMonitor(IEnumerable<string> keys, string regionName = null)
+        {
+            throw new NotSupportedException("LocalFileCache does not support the ability to create change monitors.");
+        }
+
+        public override long GetCount(string regionName = null)
+        {
+            throw new NotSupportedException("LocalFileCache does not support the ability to count items.");
+        }
+
+        public override bool Contains(string key, string regionName = null)
+        {
+            if (regionName != null)
+            {
+                throw new NotSupportedException("The parameter regionName must be null.");
+            }
+
+            try
+            {
+                return MemoryCache.Default.Contains(key) || FindFile(GetPath(key)) != null;
+            }
+            catch
+            {
+                return false;
+            }
+        }
+
+        public override object Get(string key, string regionName = null)
+        {
+            if (regionName != null)
+            {
+                throw new NotSupportedException("The parameter regionName must be null.");
+            }
+
+            var value = MemoryCache.Default.Get(key);
+
+            if (value == null)
+            {
+                try
+                {
+                    var path = FindFile(GetPath(key));
+
+                    if (path != null)
+                    {
+                        long creationTime = File.GetLastWriteTimeUtc(path).ToBinary();
+
+                        using (FileStream fileStream = new FileStream(path, FileMode.Open))
+                        using (MemoryStream memoryStream = new MemoryStream((int)(fileStream.Length + 8)))
+                        {
+                            memoryStream.Write(BitConverter.GetBytes(creationTime), 0, 8);
+                            fileStream.CopyTo(memoryStream);
+                            value = memoryStream.GetBuffer();
+                        }
+                    }
+                }
+                catch
+                {
+                }
+            }
+
+            return value;
+        }
+
+        public override CacheItem GetCacheItem(string key, string regionName = null)
+        {
+            var value = Get(key, regionName);
+            return value != null ? new CacheItem(key, value) : null;
+        }
+
+        public override IDictionary<string, object> GetValues(IEnumerable<string> keys, string regionName = null)
+        {
+            if (regionName != null)
+            {
+                throw new NotSupportedException("The parameter regionName must be null.");
+            }
+
+            var values = new Dictionary<string, object>();
+
+            foreach (string key in keys)
+            {
+                values[key] = Get(key);
+            }
+
+            return values;
+        }
+
+        public override void Set(string key, object value, CacheItemPolicy policy, string regionName = null)
+        {
+            if (regionName != null)
+            {
+                throw new NotSupportedException("The parameter regionName must be null.");
+            }
+
+            var buffer = value as byte[];
+
+            if (buffer == null)
+            {
+                throw new NotSupportedException("The parameter value must be a byte[].");
+            }
+
+            MemoryCache.Default.Set(key, buffer, policy);
+
+            var extension = GetFileExtension(buffer);
+
+            if (extension != null)
+            {
+                var path = GetPath(key) + extension;
+                Directory.CreateDirectory(Path.GetDirectoryName(path));
+
+                using (FileStream fileStream = new FileStream(path, FileMode.Create))
+                {
+                    fileStream.Write(buffer, 8, buffer.Length - 8);
+                }
+            }
+        }
+
+        public override void Set(CacheItem item, CacheItemPolicy policy)
+        {
+            Set(item.Key, item.Value, policy, item.RegionName);
+        }
+
+        public override void Set(string key, object value, DateTimeOffset absoluteExpiration, string regionName = null)
+        {
+            Set(key, value, new CacheItemPolicy { AbsoluteExpiration = absoluteExpiration }, regionName);
+        }
+
+        public override object AddOrGetExisting(string key, object value, CacheItemPolicy policy, string regionName = null)
+        {
+            var oldValue = Get(key, regionName);
+            Set(key, value, policy);
+            return oldValue;
+        }
+
+        public override CacheItem AddOrGetExisting(CacheItem item, CacheItemPolicy policy)
+        {
+            var oldItem = GetCacheItem(item.Key, item.RegionName);
+            Set(item, policy);
+            return oldItem;
+        }
+
+        public override object AddOrGetExisting(string key, object value, DateTimeOffset absoluteExpiration, string regionName = null)
+        {
+            return AddOrGetExisting(key, value, new CacheItemPolicy { AbsoluteExpiration = absoluteExpiration }, regionName);
+        }
+
+        public override object Remove(string key, string regionName = null)
+        {
+            var oldValue = Get(key, regionName);
+            MemoryCache.Default.Remove(key);
+
+            try
+            {
+                var path = FindFile(GetPath(key));
+
+                if (path != null)
+                {
+                    File.Delete(path);
+                }
+            }
+            catch
+            {
+            }
+
+            return oldValue;
+        }
+
+        private string GetPath(string key)
+        {
+            return Path.Combine(directory, key);
+        }
+
+        private static string FindFile(string path)
+        {
+            if (!string.IsNullOrEmpty(Path.GetExtension(path)))
+            {
+                return path;
+            }
+
+            string directoryName = Path.GetDirectoryName(path);
+
+            if (Directory.Exists(directoryName))
+            {
+                return Directory.EnumerateFiles(directoryName, Path.GetFileName(path) + ".*").FirstOrDefault();
+            }
+
+            return null;
+        }
+
+        private static readonly Tuple<string, byte[]>[] fileTypes = new Tuple<string, byte[]>[]
+        {
+            new Tuple<string, byte[]>(".png", new byte[] { 0x89, 0x50, 0x4E, 0x47, 0xD, 0xA, 0x1A, 0xA }),
+            new Tuple<string, byte[]>(".jpg", new byte[] { 0xFF, 0xD8, 0xFF, 0xE0, 0, 0x10, 0x4A, 0x46, 0x49, 0x46, 0 }),
+            new Tuple<string, byte[]>(".bmp", new byte[] { 0x42, 0x4D }),
+            new Tuple<string, byte[]>(".gif", new byte[] { 0x47, 0x49, 0x46 }),
+            new Tuple<string, byte[]>(".tif", new byte[] { 0x49, 0x49, 42, 0 }),
+            new Tuple<string, byte[]>(".tif", new byte[] { 0x4D, 0x4D, 0, 42 }),
+            new Tuple<string, byte[]>(".wdp", new byte[] { 0x49, 0x49, 0xBC }),
+        };
+
+        private static string GetFileExtension(byte[] buffer)
+        {
+            string extension = null;
+            DateTime creationTime = DateTime.FromBinary(BitConverter.ToInt64(buffer, 0));
+
+            if (creationTime.Kind == DateTimeKind.Utc && creationTime <= DateTime.UtcNow)
+            {
+                Func<Tuple<string, byte[]>, bool> match =
+                    t =>
+                    {
+                        int i = 0;
+                        if (t.Item2.Length + 8 <= buffer.Length)
+                        {
+                            while (i < t.Item2.Length && t.Item2[i] == buffer[i + 8])
+                            {
+                                i++;
+                            }
+                        }
+                        return i == t.Item2.Length;
+                    };
+
+                extension = fileTypes.Where(match).Select(t => t.Item1).FirstOrDefault();
+            }
+
+            return extension;
+        }
+    }
+}

Caching/ImageFileCache/ImageFileCache.csproj

@@ -0,0 +1,50 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <PropertyGroup>
+    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+    <ProductVersion>8.0.30703</ProductVersion>
+    <SchemaVersion>2.0</SchemaVersion>
+    <ProjectGuid>{86470440-FEE2-4120-AF5A-3762FB9C536F}</ProjectGuid>
+    <OutputType>Library</OutputType>
+    <AppDesignerFolder>Properties</AppDesignerFolder>
+    <RootNamespace>Caching</RootNamespace>
+    <AssemblyName>ImageFileCache</AssemblyName>
+    <TargetFrameworkVersion>v4.0</TargetFrameworkVersion>
+    <FileAlignment>512</FileAlignment>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
+    <DebugSymbols>true</DebugSymbols>
+    <DebugType>full</DebugType>
+    <Optimize>false</Optimize>
+    <OutputPath>bin\Debug\</OutputPath>
+    <DefineConstants>DEBUG;TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
+    <DebugType>none</DebugType>
+    <Optimize>true</Optimize>
+    <OutputPath>bin\Release\</OutputPath>
+    <DefineConstants>TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <ItemGroup>
+    <Reference Include="System" />
+    <Reference Include="System.Core" />
+    <Reference Include="System.Runtime.Caching" />
+  </ItemGroup>
+  <ItemGroup>
+    <Compile Include="ImageFileCache.cs" />
+    <Compile Include="Properties\AssemblyInfo.cs" />
+  </ItemGroup>
+  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
+  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
+       Other similar extension points exist, see Microsoft.Common.targets.
+  <Target Name="BeforeBuild">
+  </Target>
+  <Target Name="AfterBuild">
+  </Target>
+  -->
+</Project>

Caching/ImageFileCache/Properties/AssemblyInfo.cs

@@ -0,0 +1,36 @@
+using System.Reflection;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+
+// General Information about an assembly is controlled through the following 
+// set of attributes. Change these attribute values to modify the information
+// associated with an assembly.
+[assembly: AssemblyTitle("ImageFileCache")]
+[assembly: AssemblyDescription("ObjectCache implementation based on local image files")]
+[assembly: AssemblyConfiguration("")]
+[assembly: AssemblyCompany("")]
+[assembly: AssemblyProduct("ImageFileCache")]
+[assembly: AssemblyCopyright("Copyright © 2012 Clemens Fischer")]
+[assembly: AssemblyTrademark("")]
+[assembly: AssemblyCulture("")]
+
+// Setting ComVisible to false makes the types in this assembly not visible 
+// to COM components.  If you need to access a type in this assembly from 
+// COM, set the ComVisible attribute to true on that type.
+[assembly: ComVisible(false)]
+
+// The following GUID is for the ID of the typelib if this project is exposed to COM
+[assembly: Guid("0483659a-9743-41a2-9505-9c1a4d9ecc06")]
+
+// Version information for an assembly consists of the following four values:
+//
+//      Major Version
+//      Minor Version 
+//      Build Number
+//      Revision
+//
+// You can specify all the values or you can default the Build and Revision Numbers 
+// by using the '*' as shown below:
+// [assembly: AssemblyVersion("1.0.*")]
+[assembly: AssemblyVersion("1.0.0.0")]
+[assembly: AssemblyFileVersion("1.0.0.0")]

MapControl.sln

@@ -9,6 +9,8 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SampleApplication", "Sample
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SurfaceApplication", "SampleApps\SurfaceApplication\SurfaceApplication.csproj", "{6285FB9D-B7EA-469A-B464-224077967167}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ImageFileCache", "Caching\ImageFileCache\ImageFileCache.csproj", "{86470440-FEE2-4120-AF5A-3762FB9C536F}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -59,6 +61,16 @@ Global
 		{6285FB9D-B7EA-469A-B464-224077967167}.Release|Mixed Platforms.ActiveCfg = Release|Any CPU
 		{6285FB9D-B7EA-469A-B464-224077967167}.Release|Mixed Platforms.Build.0 = Release|Any CPU
 		{6285FB9D-B7EA-469A-B464-224077967167}.Release|x86.ActiveCfg = Release|Any CPU
+		{86470440-FEE2-4120-AF5A-3762FB9C536F}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{86470440-FEE2-4120-AF5A-3762FB9C536F}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{86470440-FEE2-4120-AF5A-3762FB9C536F}.Debug|Mixed Platforms.ActiveCfg = Debug|Any CPU
+		{86470440-FEE2-4120-AF5A-3762FB9C536F}.Debug|Mixed Platforms.Build.0 = Debug|Any CPU
+		{86470440-FEE2-4120-AF5A-3762FB9C536F}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{86470440-FEE2-4120-AF5A-3762FB9C536F}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{86470440-FEE2-4120-AF5A-3762FB9C536F}.Release|Any CPU.Build.0 = Release|Any CPU
+		{86470440-FEE2-4120-AF5A-3762FB9C536F}.Release|Mixed Platforms.ActiveCfg = Release|Any CPU
+		{86470440-FEE2-4120-AF5A-3762FB9C536F}.Release|Mixed Platforms.Build.0 = Release|Any CPU
+		{86470440-FEE2-4120-AF5A-3762FB9C536F}.Release|x86.ActiveCfg = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE

MapControl/TileImageLoader.cs

@@ -5,14 +5,12 @@
 using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
-using System.Collections.Specialized;
 using System.Diagnostics;
 using System.IO;
 using System.Linq;
 using System.Net;
 using System.Runtime.Caching;
 using System.Threading;
-using System.Windows;
 using System.Windows.Media.Imaging;
 using System.Windows.Threading;
 
@@ -26,6 +24,17 @@ namespace MapControl
         private readonly TileLayer tileLayer;
         private readonly ConcurrentQueue<Tile> pendingTiles = new ConcurrentQueue<Tile>();
 
+        /// <summary>
+        /// Default Name of an ObjectCache instance that is assigned to the Cache property.
+        /// </summary>
+        public static readonly string DefaultCacheName = "TileCache";
+
+        /// <summary>
+        /// Default value for the directory where an ObjectCache instance may save cached data.
+        /// </summary>
+        public static readonly string DefaultCacheDirectory =
+            Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.CommonApplicationData), "MapControl");
+
         /// <summary>
         /// The ObjectCache used to cache tile images.
         /// The default is System.Runtime.Caching.MemoryCache.Default.
@@ -48,53 +57,11 @@ namespace MapControl
         /// </summary>
         public static TimeSpan CacheUpdateAge { get; set; }
 
-        /// <summary>
-        /// Creates an instance of the ObjectCache-derived type T and sets the static Cache
-        /// property to this instance. Class T must (like System.Runtime.Caching.MemoryCache)
-        /// provide a constructor with two parameters, first a string that gets the name of
-        /// the cache instance, second a NameValueCollection that gets the config parameter.
-        /// If config is null, a new NameValueCollection is created. If config does not already
-        /// contain an entry with key "directory", a new entry is added with this key and a
-        /// value that specifies the path to an application data directory where the cache
-        /// implementation may store persistent cache data files.
-        /// </summary>
-        public static void CreateCache<T>(NameValueCollection config = null) where T : ObjectCache
-        {
-            if (config == null)
-            {
-                config = new NameValueCollection(1);
-            }
-
-            if (config["directory"] == null)
-            {
-                config["directory"] = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.CommonApplicationData), "MapControl");
-            }
-
-            try
-            {
-                Cache = (ObjectCache)Activator.CreateInstance(typeof(T), "TileCache", config);
-            }
-            catch (Exception ex)
-            {
-                Trace.TraceWarning("Could not create instance of type {0} with String and NameValueCollection constructor parameters: {1}", typeof(T), ex.Message);
-                throw;
-            }
-        }
-
         static TileImageLoader()
         {
             Cache = MemoryCache.Default;
             CacheExpiration = TimeSpan.FromDays(30d);
             CacheUpdateAge = TimeSpan.FromDays(1d);
-
-            Application.Current.Exit += (o, e) =>
-            {
-                IDisposable disposableCache = Cache as IDisposable;
-                if (disposableCache != null)
-                {
-                    disposableCache.Dispose();
-                }
-            };
         }
 
         internal TileImageLoader(TileLayer tileLayer)
@@ -151,7 +118,7 @@ namespace MapControl
                             Cache.Remove(key);
                             pendingTiles.Enqueue(tile);
                         }
-                        else if (GetCreationTime(imageBuffer) + CacheUpdateAge < DateTime.UtcNow)
+                        else if (IsCacheOutdated(imageBuffer))
                         {
                             // update cached image
                             outdatedTiles.Add(tile);
@@ -206,21 +173,15 @@ namespace MapControl
                 using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
                 using (Stream responseStream = response.GetResponseStream())
                 {
-                    if (response.ContentLength > 0)
+                    long length = response.ContentLength;
+                    long creationTime = DateTime.UtcNow.ToBinary();
+
+                    using (MemoryStream memoryStream = length > 0 ? new MemoryStream((int)length + 8) : new MemoryStream())
                     {
-                        using (MemoryStream memoryStream = new MemoryStream((int)response.ContentLength + 8))
+                        memoryStream.Write(BitConverter.GetBytes(creationTime), 0, 8);
-                        {
+                        responseStream.CopyTo(memoryStream);
-                            CopyWithCreationTime(responseStream, memoryStream);
+
-                            buffer = memoryStream.GetBuffer();
+                        buffer = length > 0 ? memoryStream.GetBuffer() : memoryStream.ToArray();
-                        }
-                    }
-                    else
-                    {
-                        using (MemoryStream memoryStream = new MemoryStream())
-                        {
-                            CopyWithCreationTime(responseStream, memoryStream);
-                            buffer = memoryStream.ToArray();
-                        }
                     }
                 }
 
@@ -245,13 +206,20 @@ namespace MapControl
             return buffer;
         }
 
-        private bool CreateTileImage(Tile tile, byte[] buffer)
+        private bool IsCacheOutdated(byte[] imageBuffer)
+        {
+            long creationTime = BitConverter.ToInt64(imageBuffer, 0);
+
+            return DateTime.FromBinary(creationTime) + CacheUpdateAge < DateTime.UtcNow;
+        }
+
+        private bool CreateTileImage(Tile tile, byte[] imageBuffer)
         {
             BitmapImage bitmap = new BitmapImage();
 
             try
             {
-                using (Stream stream = new MemoryStream(buffer, 0, buffer.Length - 8, false))
+                using (Stream stream = new MemoryStream(imageBuffer, 8, imageBuffer.Length - 8, false))
                 {
                     bitmap.BeginInit();
                     bitmap.CacheOption = BitmapCacheOption.OnLoad;
@@ -270,17 +238,6 @@ namespace MapControl
             return true;
         }
 
-        private static DateTime GetCreationTime(byte[] imageBuffer)
-        {
-            return new DateTime(BitConverter.ToInt64(imageBuffer, imageBuffer.Length - 8));
-        }
-
-        private static void CopyWithCreationTime(Stream source, Stream target)
-        {
-            source.CopyTo(target);
-            target.Write(BitConverter.GetBytes(DateTime.UtcNow.Ticks), 0, 8);
-        }
-
         private static void TraceWarning(string format, params object[] args)
         {
             Trace.TraceWarning("[{0:00}] {1}", Thread.CurrentThread.ManagedThreadId, string.Format(format, args));

SampleApps/SampleApplication/App.config

@@ -7,8 +7,8 @@
     </configSections>
     <applicationSettings>
         <SampleApplication.Properties.Settings>
-            <setting name="UsePersistentCache" serializeAs="String">
+            <setting name="TileCache" serializeAs="String">
-                <value>False</value>
+                <value />
             </setting>
         </SampleApplication.Properties.Settings>
     </applicationSettings>

SampleApps/SampleApplication/MainWindow.xaml

@@ -21,7 +21,7 @@
                  map content without using their APIs (i.e. Google Maps API or Bing Maps API).
                  Hence the declarations below are for demonstration purpose only. -->
 
-            <map:TileLayer Name="Google Maps" Description="Google Maps - © {y} Google"
+            <!--<map:TileLayer Name="Google Maps" Description="Google Maps - © {y} Google"
                            TileSource="http://mt{i}.google.com/vt/x={x}&amp;y={y}&amp;z={z}" MaxZoomLevel="20"/>
             <map:TileLayer Name="Google Images" Description="Google Maps - © {y} Google"
                            TileSource="http://khm{i}.google.com/kh/v=113&amp;x={x}&amp;y={y}&amp;z={z}" MaxZoomLevel="20" HasDarkBackground="True"/>
@@ -30,7 +30,7 @@
             <map:TileLayer Name="Bing Images" Description="Bing Maps - © {y} Microsoft Corporation"
                            TileSource="http://ecn.t{i}.tiles.virtualearth.net/tiles/a{q}.jpeg?g=0" MaxZoomLevel="20" HasDarkBackground="True"/>
             <map:TileLayer Name="Bing Hybrid" Description="Bing Maps - © {y} Microsoft Corporation"
-                           TileSource="http://ecn.t{i}.tiles.virtualearth.net/tiles/h{q}.jpeg?g=0&amp;stl=h" MaxZoomLevel="20" HasDarkBackground="True"/>
+                           TileSource="http://ecn.t{i}.tiles.virtualearth.net/tiles/h{q}.jpeg?g=0&amp;stl=h" MaxZoomLevel="20" HasDarkBackground="True"/>-->
 
             <!-- The TileLayer below uses an ImageTileSource, which bypasses caching of map tile images -->
 

SampleApps/SampleApplication/MainWindow.xaml.cs

@@ -19,9 +19,16 @@ namespace SampleApplication
 
         public MainWindow()
         {
-            if (Properties.Settings.Default.UsePersistentCache)
+            switch (Properties.Settings.Default.TileCache)
             {
-                TileImageLoader.CreateCache<FileDbCache>();
+                case "FileDbCache":
+                    TileImageLoader.Cache = new FileDbCache(TileImageLoader.DefaultCacheName, TileImageLoader.DefaultCacheDirectory);
+                    break;
+                case "ImageFileCache":
+                    TileImageLoader.Cache = new ImageFileCache(TileImageLoader.DefaultCacheName, TileImageLoader.DefaultCacheDirectory);
+                    break;
+                default:
+                    break;
             }
 
             InitializeComponent();

SampleApps/SampleApplication/Properties/Settings.Designer.cs

@@ -25,10 +25,10 @@ namespace SampleApplication.Properties {
         
         [global::System.Configuration.ApplicationScopedSettingAttribute()]
         [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
-        [global::System.Configuration.DefaultSettingValueAttribute("False")]
+        [global::System.Configuration.DefaultSettingValueAttribute("")]
-        public bool UsePersistentCache {
+        public string TileCache {
             get {
-                return ((bool)(this["UsePersistentCache"]));
+                return ((string)(this["TileCache"]));
             }
         }
     }

SampleApps/SampleApplication/Properties/Settings.settings

@@ -2,8 +2,8 @@
 <SettingsFile xmlns="http://schemas.microsoft.com/VisualStudio/2004/01/settings" CurrentProfile="(Default)" GeneratedClassNamespace="SampleApplication.Properties" GeneratedClassName="Settings">
   <Profiles />
   <Settings>
-    <Setting Name="UsePersistentCache" Type="System.Boolean" Scope="Application">
+    <Setting Name="TileCache" Type="System.String" Scope="Application">
-      <Value Profile="(Default)">False</Value>
+      <Value Profile="(Default)" />
     </Setting>
   </Settings>
 </SettingsFile>

SampleApps/SampleApplication/SampleApplication.csproj

@@ -84,6 +84,10 @@
       <Project>{EF44F661-B98A-4676-927F-85D138F82300}</Project>
       <Name>FileDbCache</Name>
     </ProjectReference>
+    <ProjectReference Include="..\..\Caching\ImageFileCache\ImageFileCache.csproj">
+      <Project>{86470440-FEE2-4120-AF5A-3762FB9C536F}</Project>
+      <Name>ImageFileCache</Name>
+    </ProjectReference>
     <ProjectReference Include="..\..\MapControl\MapControl.csproj">
       <Project>{06481252-2310-414A-B9FC-D5739FDF6BD3}</Project>
       <Name>MapControl</Name>