internal class ProtcolConverter : StringConverter
    {
        public override bool
            GetStandardValuesSupported(
            ITypeDescriptorContext context)
        {
            //True - means show a Combobox
            //and False for show a Modal
            return true;
        }

        public override bool
            GetStandardValuesExclusive(
            ITypeDescriptorContext context)
        {
            //False - a option to edit values
            //and True - set values to state readonly
            return true;
        }

        public override StandardValuesCollection
            GetStandardValues(
            ITypeDescriptorContext context)
        {
            return new StandardValuesCollection(
                new string[] { "net.tcp", "http" });
        }
    }

And finally the we need to attach the string converter to the property by the following.

[TypeConverter(typeof(ProtcolConverter))]
public string ServiceProtocol
{
     get { return MediaServiceConfig.WCFProtocol; }
     set { MediaServiceConfig.WCFProtocol = value; }
}

Enjoy.

SELECT newid(),getdate()

Produces these results.

------------------------------------ -----------------------
125700F3-8FB8-496F-8EA4-35D9CB9E8415 2008-10-29 13:09:54.557
(1 row(s) affected)

The exact macth

DataContext dc = new DataContext(...)
var results =
  from row in dc.table
  where row.string_column == "Exact Match"
  select row;

Begins With:

DataContext dc = new DataContext(...)
var results =
  from row in dc.table
  where row.string_column.StartsWith("Ex")
  select row;

produces an sql match string “Ex%”

Contains

DataContext dc = new DataContext(...)
var results =
  from row in dc.table
  where row.string_column.Contains("Ex")
  select row;

Which is equivalent to “%Ex%”

Ends With

DataContext dc = new DataContext(...)
var results =
  from row in dc.table
  where row.string_column.EndsWith("Ex")
  select row;

Which is equivalent to “%Ex”

MyDataContext dc() = new MyDataContext;
var query = dc.MyTables;
query = query.Where( t=>t.id > 10);

and so I want to order it by a certain column:

query = query.OrderBy( t=>t.id )

but the problem is the order direction isn’t know before hand so at first I was stuck with the following:

if ( descending )
    query = query.OrderByDescending( t=>t.id);
else
    query = query.OrderBy(t=>t.id);

Now if there is only a few possible columns to sort against it isn’t too bad.  But when you have 10 different possible columns it really makes a lot of extra work just to control to sort direction.  So I made a little helper class that allows the following.  It works with linq and linq to sql:

query = query.OrderByAscDec( t=>t.id, descending );

here’s the static class that implments the OrderByAscDec function:

static class VPLinqExtensions
{
	public static IOrderedQueryable<TSource> OrderByAscDes<TSource, TKey>(
		this IQueryable<TSource> source,
		System.Linq.Expressions.Expression<Func<TSource,
		TKey>> keySelector, bool IsDescending)
	{
		if (IsDescending)
			return source.OrderByDescending(keySelector);
		else
			return source.OrderBy(keySelector);
	}
}

Creating a socket is easy here is how:

using System.Net.Sockets;

//...

// Creating a connection
Socket client;
client = new Socket( AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp );
client.Connect(hostName, port);
client.Blocking = false; // This needs to be done after Connect or it will error out.

Here’s how to write data to the socket

// Writing information to the socket
byte[] buffer = ASCIIEncoding.ASCII.GetBytes(messageText);
foreach (byte c in buffer)
{
	SocketError err = SocketError.WouldBlock;
	// need to try again if the socket would have blocked
	while ( err == SocketError.WouldBlock )
	{
		// this version of Send must be used or an exception would be thrown, which I feel is a pain
		// to deal with -- this way you can see handle the error appropriately.
		client.Send(buffer, 0, 1, SocketFlags.None, out err );
	}

	if ( err != SocketError.Success )
	{
		// handle error
		break;
	}
}

And now code to read from a non-blocking socket

// Reading from the socket
// this loop keeps going until there is a socket error or a '0' byte is read which
// in this example marks the end of the message
System.Text.StringBuilder message = new System.Text.StringBuilder();
while ( true )
{
	byte c = 0;
	int bytesRead;
	SocketError err;
	// read a character.
	bytesRead = client.Receive(buffer, 0, 1, SocketFlags.None, out err );
	// checking what happened
	if ( SocketError.Success == err )
	{
		// read a byte!  Let's process it
		if ( bytesRead > 0 )
		{
			// found a null character -- in this case it makes the end of a message.
			if (c == 0)
			{
				// null terminated message received
				break;
			}
			else
				message.Append((char)c);
			}
		}
	}
	else if ( SocketError.WouldBlock != err )
	{
		break;
	}
}

string uri = "http://finance.google.com/finance/historical?cid=667226&startdate=Sep+9%2C+2007&enddate=Sep+10%2C+2008&output=csv";
WebRequest request = WebRequest.Create(uri);
WebResponse response = request.GetResponse();
var stream = response.GetResponseStream();
StreamReader reader = new StreamReader(stream, Encoding.GetEncoding("utf-8"));
string page = reader.ReadToEnd();

There you go. Very simple isn’t it? Just got to love .Net

int begin = System.Environment.TickCount
... do something
int end = System.Environment.TickCount
int elapsed = end - begin;

System.IO.DirectoryInfo di = new System.IO.DirectoryInfo(Program.DataDirectory);
System.IO.FileInfo[] files = di.GetFiles("*.txt");

string appDir = AppDomain.CurrentDomain.BaseDirectory;

Well it’s been many years and computers have improved a great deal as have the tools to program them.  So I wrote another Mandelbrot explorer.

What is the Mandelbrot set? Well….  In short it is X_n+1 = X_n² + C iterated until the magnitude of X_n is greater than 4 or the maximum number of iterations is met then the number of iterations is used as the color of the pixel.  X_n is a complex number, C is another complex number where the x coordinate of the pixel defines the real part and the y coordinate defines the imaginary part of the number. The magnitude is defined as X² + Absolute Value of (X_i²).  Then this process is repeated for each pixel.  Holy smoke that is a mouthful!

Anyway take a peek at the code if you’d like and surely get the app and have fun exploring the Mandelbrot set.

To zoom in a spot just click on it.  The number is the number of iterations.  The more iterations the deeper the pattern goes (well until you run into percision problems).

Mandelbrot Executable

Mandelbrot source code.

Have fun!