C#

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <configSections>
    <sectionGroup name="common">
      <section name="logging" type="Common.Logging.ConfigurationSectionHandler, Common.Logging" />
    </sectionGroup>
  </configSections>
  <nlog xmlns="http://www.nlog-project.org/schemas/NLog.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    <targets>
     </targets>
    <rules>
    </rules>
  </nlog>


using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Common.Logging;
using sample;
using System.Configuration;
using System.Xml.Linq;  
using NLog;

namespace sample
{
    public class Etest
    {
        private static Logger logger = LogManager.GetCurrentClassLogger(); 
        private static ILog log = LogManager.GetCurrentClassLogger();
}
}

1. The following code is from the app.config file:
<connectionStrings>
    
    <add name="esample.Properties.Settings.devtestConnectionString"
      connectionString="Data Source=dev;Initial Catalog=devtest;Integrated Security=True"
      providerName="System.Data.SqlClient" />    
  </connectionStrings>

2. The following is from the settings.settings file
<?xml version='1.0' encoding='utf-8'?>
<SettingsFile xmlns="http://schemas.microsoft.com/VisualStudio/2004/01/settings" CurrentProfile="(Default)" GeneratedClassNamespace="esample.Properties" GeneratedClassName="Settings">
  <Profiles />
  <Settings>
    <Setting Name="devtestConnectionString" Type="(Connection string)" Scope="Application">
      <DesignTimeValue Profile="(Default)"><?xml version="1.0" encoding="utf-16"?>
<SerializableConnectionString xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <ConnectionString>Data Source=dev;Initial Catalog=devtest;Integrated Security=True</ConnectionString>
  <ProviderName>System.Data.SqlClient</ProviderName>
</SerializableConnectionString></DesignTimeValue>
      <Value Profile="(Default)">Data Source=dev;Initial Catalog=devtest;Integrated Security=True</Value>
    </Setting>
   </Settings>
</SettingsFile>

The following is from the settings.designer.cs file
namespace esample.Properties {
    
    
    [global::System.Runtime.CompilerServices.CompilerGeneratedAttribute()]
    [global::System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.VisualStudio.Editors.SettingsDesigner.SettingsSingleFileGenerator", "9.0.0.0")]
    internal sealed partial class Settings : global::System.Configuration.ApplicationSettingsBase {
        
        private static Settings defaultInstance = ((Settings)(global::System.Configuration.ApplicationSettingsBase.Synchronized(new Settings())));
        
        public static Settings Default {
            get {
                return defaultInstance;
            }
        }
        
        [global::System.Configuration.ApplicationScopedSettingAttribute()]
        [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
        [global::System.Configuration.SpecialSettingAttribute(global::System.Configuration.SpecialSetting.ConnectionString)]
        [global::System.Configuration.DefaultSettingValueAttribute("Data Source=dev;Initial Catalog=devtest;Integrated Security=True")]
        public string devtestConnectionString {
            get {
                return ((string)(this["devtestConnectionString"]));
            }
        }
        
        
    }
}

The following is from the *.designer.cs

namespace esample
{
	using System.Data.Linq;
	using System.Data.Linq.Mapping;
	using System.Data;
	using System.Collections.Generic;
	using System.Reflection;
	using System.Linq;
	using System.Linq.Expressions;
	using System.ComponentModel;
	using System;
        using System.Configuration;
	
	
	[System.Data.Linq.Mapping.DatabaseAttribute(Name="devtest")]
	public partial class esampleDataContext : System.Data.Linq.DataContext
	{
		
		private static System.Data.Linq.Mapping.MappingSource mappingSource = new AttributeMappingSource();

		
		public esampleDataContext() :

        base(global::esample.Properties.Settings.Default.devtestConnectionString, mappingSource)
        //base(ConfigurationManager.ConnectionStrings["esample.Properties.Settings.devtestConnectionString"].ConnectionString,  mappingSource)
          {	
			OnCreated();
		}
		
		public esampleDataContext(string connection) : 
				base(connection, mappingSource)
		{
			OnCreated();
		}

Ive used a couple of the GoF pattens in my applications as well as read articles and books on them, i however want to find out from the rest of you guys where you used the patterns before?
So, if you could list examples or short descriptions where you have used the various Behavioral, Creational and Structural patterns in real production applications that would be awesome!