How to switch between SQL Server and SQL Server Compact with Entity Framework

I wanted to be able to save data to either a database on a SQL Server 2008 or an equivalent database on SQL Server Compact 3.5 with the minimum of hassle. Enter the new features of Entity Framework 4.0. I followed POCO in the Entity Framework: Part 1 - The Experience to turn off code generation.

I added two EDMs to my project, one for each database. I modified the ObjectContext class to accept different contexts, i.e.:

public class TestContext : ObjectContext
{
    public TestContext(string contextName) : base("name=" + contextName, contextName)
    {
        _projects = CreateObjectSet<Project>();
    }

    public ObjectSet<Project> Projects
    {
        get
        {
            return _projects;
        }
    }
    private ObjectSet<Project> _projects;
}

After that, I can now connect to either database by specifying either:

var compactContext = new TestContext("CompactEntities");

OR

var context = new TestContext("Entities");

Now I can use the same class files to both databases, and sync up the data in both with quite easily. The only redundancy is the EDMs, but since they are generated by Visual Studio, I don't care.

All too easy.

My HSL colour class

Want a unique set of colours without having to do any work? You need HSL.

Use:

for (var i = 0; i < 10; i++)
 (Color)new ColorHsl((byte)((float)i / 10 * 255), 127, 127)

Class (Note, I mostly ripped this off from elsewhere, but mine 1) actually works, 2) is easy to use.):

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Media;

namespace UserInterface
{
   public class ColorHsl
   {
       public ColorHsl(byte h, byte s, byte l)
       {
           H = h;
           S = s;
           L = l;
       }

       public byte H, S, L;

       public static implicit operator Color(ColorHsl colorHsl)
       {
           double r, g, b, h, s, l; //this function works with floats between 0 and 1
           double temp1, temp2, tempr, tempg, tempb;
           h = colorHsl.H / 256.0;
           s = colorHsl.S / 256.0;
           l = colorHsl.L / 256.0;

           //If saturation is 0, the color is a shade of gray
           if (s == 0)
           {
               r = g = b = l;
           }
           else
           {
               //Set the temporary values      
               if (l < 0.5)
               {
                   temp2 = l * (1 + s);
               }
               else
               {
                   temp2 = (l + s) - (l * s);
               }

               temp1 = 2 * l - temp2;
               tempr = h + 1.0 / 3.0;

               if (tempr > 1)
               {
                   tempr--;
               }

               tempg = h;
               tempb = h - 1.0 / 3.0;
               if (tempb < 0)
                   tempb++;

               //Red     
               if (tempr < 1.0 / 6.0) r = temp1 + (temp2 - temp1) * 6.0 * tempr;
               else if (tempr < 0.5) r = temp2;
               else if (tempr < 2.0 / 3.0) r = temp1 + (temp2 - temp1) * ((2.0 / 3.0) - tempr) * 6.0;
               else r = temp1;

               //Green       
               if (tempg < 1.0 / 6.0) g = temp1 + (temp2 - temp1) * 6.0 * tempg;
               else if (tempg < 0.5) g = temp2;
               else if (tempg < 2.0 / 3.0) g = temp1 + (temp2 - temp1) * ((2.0 / 3.0) - tempg) * 6.0;
               else g = temp1;

               //Blue    
               if (tempb < 1.0 / 6.0) b = temp1 + (temp2 - temp1) * 6.0 * tempb;
               else if (tempb < 0.5) b = temp2;
               else if (tempb < 2.0 / 3.0) b = temp1 + (temp2 - temp1) * ((2.0 / 3.0) - tempb) * 6.0;
               else b = temp1;
           }

           return Color.FromRgb(Convert.ToByte(r * 255), Convert.ToByte(g * 255), Convert.ToByte(b * 255));
       }
   }
}