LINQPad + SQLite => An Hour Saved

Recently, I lost all the images for my website due to some technical issues. All the images were also being saved in a SQLite database with the description as the file name. Instead of writing a brand new console app, I fired up LINQPad, added the SQLite driver and saved myself an hour's time

var images = (from img in ImageTables where img.Description.StartsWith("images") select img);
foreach (var img in images) {
var fi = new FileInfo(img.Description);
fi.Directory.Create();
File.WriteAllBytes(fi.FullName, img.Image);
img.Description.Dump();
}

iPhone App Compiles For Simulator And Not For Device

I was writing a quick app using the MKMapView and CoreLocation. The application compiled fine for the simulator and pulled up the correct view when running on the simulator. Once I changed the config to compile to the device, all hell broke lose. The compiler started generating link errors. After a couple of hours of hitting my head against the wall I was able to find the solution here. But essentially, the project.pbxproj file contained items that shouldn't have been in the file. After I updated the framework search path, the application compiled correctly. Below is the fix

FRAMEWORK_SEARCH_PATHS = "$(inherited)";

Wondering About Getting My Own Blog Site

I am really tired of formatting code for the blogspot.  It is a major PITA.  Wondering whether hosting my own blogs would make things easier?  Then again, I don’t blog enough to justify the cost…

C#, Generics, and Reflection

On my current project, we are using a homegrown ORM framework that works against stored procedures. The framework is fairly slick, uses generics, and does save time by producing basic plumbing as well as the stored procedures. As to why we are not using NHibernate and Spring.NET, the client does not have much faith in Open Source projects and only allows stored procedures to access their database. Though I have opinions about that, we will not share those here.

Since the application we are writing must coexist side by side with the legacy application and it’s other modules, we must also use the legacy tables. The application uses lots of lookup tables, which could really all be rolled up into a single table with types but I digress. We decided that instead of having several classes to do the CRUD for the lookup types, we will be writing a single class to manage all of lookup tables.

So my team member, Jes, created the stored procedure to let us return any of the lookup values based on the parameters that we pass in. The problem reared its ugly head when she tried to use the framework in association with a single common stored procedure. The framework expects the generic type parameter and we don’t have this value till runtime and there is not much that could be done here without the use of reflection.

Reflection allows an application to use introspection to to work with some piece of code and can be a very powerful tool in the bag o’ tricks. I have used reflection extensively in my days of java development but not much in the .NET world. While thinking about the problem, I started thinking about reflection once again and started playing with it. As it turns out, reflection is even easier in .NET than it was in java (which was really cool and easy).

After playing with it a little, I realized that you can check to see if a method is a generic method and whether it has a generic type parameter. Once I realized that, I knew our problem had been solved. Below is an example of a class that has a method with a type parameter. The code uses reflection to dynamically pass the parameter type. No, the code is not production quality and makes assumptions that should always be validated but that’s not the point here

using System;
using System;
namespace Test {
  public class Hello {
    public void PrintTypeName() {
      Console.WriteLine("Parameter Type Name: {0}", typeof(T).FullName);
    }
  }
  class Program {
    static void Main(string[] args) {
      // instantiate the object and store the type information...will need it again
      var instance = Activator.CreateInstance(Type.GetType("Test.Hello"));
      var type = instance.GetType();

      // lookup the method you want to work on.  This is just for demonstration purposes
      // only...there are better ways to lookup information
      var m = type.GetMethod("PrintTypeName");

      // this call makes the method into a generic method passing in the type parameter
      // information.  DO note that you must assign back the value returned from the
      // method call.  If you fail to do the assignment, you will get the following exception
      // which I did but didn't find much help on google and is the whole point of this blog
      // Exception: "Late bound operations cannot be performed on types or methods for which ContainsGenericParameters is true"
      m = m.MakeGenericMethod(type);

      // now that you have a generic method, all that is needed is the invocation.
      // Since there are no argument values for the method, we are passing in the null
      // Also note that we must have an instance to execute the method on since the method is not
      // static.  If the method was static, instance would be passed in as null as well
      m.Invoke(instance, null);

      // Sam Bradford of OU won the Heisman today [12.13.2008]
      // Boomer Sooner!
      Console.Write("Press any key...");
      Console.ReadKey();
    }
  }
}

Going Home

My Employer and I have agreed that I can work from home starting September. This is a big change for them as I live 600 miles away from the office but something they have agreed to try with me.

I am a little nervous, but also excited about. I already have an office at home and the family is excited about the prospects as well

Text Inverter Application

Once upon a long time, I worked for a mega company (now, I work for a different mega company) and we had disparate systems. We had applications written in COBOL, Delphi, and of course, java.

Applications started out on the MainFrame eons ago and a decision was made to invert the order numbers. I, for the life of me, cannot remember what the reason was but anyhow, our java apps used the correct order number and there was a disparity. Sometimes we had to take the copy the order number from the MainFrame into our java apps/sql executor to see why things were not running correctly. It was a pain in the butt to invert the numbers so I wrote this utility in 2003 with Sharp Develop to invert the values. Double clicking the textbox copies the value to the clipboard (wonder what it will do under Vista).

This might come in handy some day or to anyone else. The file can be downloaded here: http://www.mediafire.com/download.php?nmq3xthldgm

Stuff You Need

Eclipse/NetBeans
Visual Studio (latest version)
Resharper
NHibernate
Spring.NET
Firebug
Fiddler
Process Explorer
TCPView
SQL Server Profiler
Microsoft Virtual PC (only because it's free)
ISO Recorder