--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/HowTo/Aspects/CacheAspect.cs	Thu Mar 27 21:46:09 2014 +0400
@@ -0,0 +1,87 @@
+using System;
+using System.Reflection;
+
+using NUnit.Framework;
+
+using BLToolkit.Aspects;
+using BLToolkit.Reflection;
+
+namespace HowTo.Aspects
+{
+	public /*[a]*/abstract/*[/a]*/ class TestClass
+	{
+		public static int Value;
+
+		// This is a method we will cache. Cached return value depends on input parameters.
+		// We will change the 'Value' field outside of the class and see how it affects the result.
+		//
+		[/*[a]*/Cache/*[/a]*/(MaxCacheTime=500, IsWeak=false)]
+		public /*[a]*/virtual/*[/a]*/ int CachedMethod(int p1, int p2)
+		{
+			return Value;
+		}
+
+		public static TestClass CreateInstance()
+		{
+			// Use TypeAccessor to create an instance of an abstract class.
+			//
+			return /*[a]*/TypeAccessor/*[/a]*/<TestClass>.CreateInstance();
+		}
+	}
+
+	[TestFixture]
+	public class CacheAspectTest
+	{
+		[Test]
+		public void Test1()
+		{
+			TestClass tc = TestClass.CreateInstance();
+
+			DateTime begin = DateTime.Now;
+
+			// Initial setup for the test static variable.
+			//
+			TestClass.Value = 777;
+
+			while (tc.CachedMethod(2, 2) == 777)
+			{
+				// This change will not affect the Test method return value for 500 ms.
+				//
+				TestClass.Value++;
+			}
+
+			double totalMilliseconds = (DateTime.Now - begin).TotalMilliseconds;
+
+			Assert.GreaterOrEqual(totalMilliseconds, 500);
+		}
+
+		[Test]
+		public void Test2()
+		{
+			TestClass tc = TestClass.CreateInstance();
+
+			// Return value depends on parameter values.
+			//
+			TestClass.Value = /*[a]*/1/*[/a]*/; Assert.AreEqual(/*[a]*/1/*[/a]*/, tc.CachedMethod(1, 1));
+			TestClass.Value = /*[a]*/2/*[/a]*/; Assert.AreEqual(/*[a]*/1/*[/a]*/, tc.CachedMethod(1, 1)); // no change
+			TestClass.Value = /*[a]*/3/*[/a]*/; Assert.AreEqual(/*[a]*/3/*[/a]*/, tc.CachedMethod(2, 1));
+
+			// However we can clear cache manually.
+			// For particular method:
+			//
+			CacheAspect.ClearCache(typeof(TestClass), "CachedMethod", typeof(int), typeof(int));
+			TestClass.Value = /*[a]*/4/*[/a]*/; Assert.AreEqual(/*[a]*/4/*[/a]*/, tc.CachedMethod(2, 1));
+
+			// By MethodInfo:
+			//
+			MethodInfo methodInfo = tc.GetType().GetMethod("CachedMethod", new Type[] { typeof(int), typeof(int) });
+			CacheAspect.ClearCache(methodInfo);
+			TestClass.Value = /*[a]*/5/*[/a]*/; Assert.AreEqual(/*[a]*/5/*[/a]*/, tc.CachedMethod(2, 1));
+
+			// For the all cached methods.
+			//
+			CacheAspect.ClearCache();
+			TestClass.Value = /*[a]*/6/*[/a]*/; Assert.AreEqual(/*[a]*/6/*[/a]*/, tc.CachedMethod(2, 1));
+		}
+	}
+}