program.cs

AutomaticPropertiesDefaultValues Article_src.zip PropertyInfo[] props = o.GetType().GetPropert

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.ComponentModel;
using System.Reflection;

namespace AutomaticPropertiesDefaultValues
{
	class Program
	{
		static void Main(string[] args)
		{
			TestObject to = new TestObject();

			Console.WriteLine(to.DefaultInt);
			Console.WriteLine(to.DefaultDouble);
			Console.WriteLine(to.DefaultBool);
			Console.WriteLine(to.DefaultEnum);
			Console.WriteLine(to.DefaultString ?? "<null>");
			Console.WriteLine(to.StringWithoutDefault ?? "<null>");
			Console.WriteLine(to.ValueOfPrivateProperty ?? "<null>");

			Console.WriteLine();
			Console.WriteLine();

			TestObjectInherited toi = new TestObjectInherited();
			Console.WriteLine(toi.DefaultInt);
			Console.WriteLine(toi.DefaultDouble);
			Console.WriteLine(toi.DefaultBool);
			Console.WriteLine(toi.DefaultEnum);
			Console.WriteLine(toi.DefaultString ?? "<null>");
			Console.WriteLine(toi.StringWithoutDefault ?? "<null>");
			Console.WriteLine(toi.ValueOfPrivateProperty ?? "<null>");
			Console.WriteLine(toi.InheritedDefaultValue ?? "<null>");
			Console.WriteLine(TestObjectInherited.StaticProperty ?? "<null>");

			Console.ReadLine();
		}
	}

	public class TestObjectInherited : TestObject
	{		
		[DefaultValue("This is inherited")]
		public string InheritedDefaultValue
		{
			get;
			set;
		}

		[DefaultValue("This is static!")]
		public static string StaticProperty
		{
			get;
			set;
		}
	}

	public class TestObject
	{
		public TestObject()
		{
			this.InitDefaults();
		}

		[DefaultValue(-45)]
		public int DefaultInt
		{
			get;
			set;
		}

		[DefaultValue(10.23)]
		public double DefaultDouble
		{
			get;
			set;
		}

		[DefaultValue(true)]
		public bool DefaultBool
		{
			get;
			set;
		}

		[DefaultValue(TestEnum.Value2)]
		public TestEnum DefaultEnum
		{
			get;
			set;
		}

		[DefaultValue("DefaultString!")]
		public string DefaultString
		{
			get;
			set;
		}

		public string StringWithoutDefault
		{
			get;
			set;
		}

		public string ValueOfPrivateProperty
		{
			get
			{
				return PrivateProperty;
			}
		}

		[DefaultValue("This is a private property!")]
		protected string PrivateProperty
		{
			get;
			set;		
		}
	}

	public enum TestEnum
	{
		Value1,
		Value2
	}

	public static class ExtensionsClass
	{
		/// <summary>
		/// Inititializes default values of automatic properties
		/// </summary>
		/// <param name="o">The o.</param>
		public static void InitDefaults(this object o)
		{
			PropertyInfo[] props = o.GetType().GetProperties(BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.Static);

			for (int i = 0; i < props.Length; i++)
			{
				PropertyInfo prop = props[i];				

				if (prop.GetCustomAttributes(true).Length > 0)
				{
					object[] defaultValueAttribute = prop.GetCustomAttributes(typeof(DefaultValueAttribute), true);

					if (defaultValueAttribute != null)					
					{
						DefaultValueAttribute dva = defaultValueAttribute[0] as DefaultValueAttribute;
						
						if(dva != null)
							prop.SetValue(o, dva.Value, null);								
					}
				}
			}
		}
	}

}