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Thursday, May 26, 2011

Simplifying use of SQL CE in Mango #WP7Dev (1 of n)

One of the features that the "Mango" tools introduce for Windows Phone development is a built in SQL Compact Edition (SQL CE) database. While learning about how to use it I was struck by how much better the experience could be.

As such, here is the first in what I hope will be a series of pointers and tips for making working with a database easier.

If you want to learn more about using SQL CE with Windows Phone codename "Mango" then I also recommend you check out the following on MSDN:
How to: Create a Basic Local Database Application for Windows Phone
and
Hands-On-Lab: Using local database in To-do application



When working with a database it's good practice to persist any changes to the datacache as quickly as possible. This means you'll probably end up doing something like this:
  db.MyItems.InsertOnSubmit(myNewItemInstance);
  db.SubmitChanges();
or this:
  db.MyItems.DeleteOnSubmit(anItemInstance);
  db.SubmitChanges();
quite a lot.

The only reason you may not want to do the above (Calling `SubmitChanges` after every call to `XxxxxOnSubmit()`) is if you were performing a number of insertions or deletions in a loop. In this case it may be wise (more performant) to call `SubmitChanges()` at the end.

When looking at even a short amount of code that does insertions or deletions it strikes me that there is a lot of duplication and that if those functions are always called together then it may make sense to bundle them up into a single function.

As it may not be immediately obvious how to do this (I had to explore a couple of options before I ended up with this), I present a simple class with some extension methods which does just that:

public static class TableExtensions
{
  public static void InsertAndSubmitChanges(this Table table, T entity) where T : class
  {
    table.InsertOnSubmit(entity);
    table.Context.SubmitChanges();
  }

  public static void DeleteAndSubmitChanges(this Table table, T entity) where T : class
  {
    table.DeleteOnSubmit(entity);
    table.Context.SubmitChanges();
  }
}  

By using the above class, it means that where we were previously having to write 2 lines of code we can now just write 1 and still get the same functionality!

  db.MyItems.InsertAndSubmitChanges(myNewItemInstance);

  db.MyItems.DeleteAndSubmitChanges(anItemInstance);  

I hope this helps you write less code. (In a good way of course.)
Please let me know if you find this helpful.

If you've built Windows Phone or Windows Store apps you can cross-promote them with AdDuplex to get more users.

Consumer features coming in Mango

I'm sorry but this is more shaky video. I hope you can cope.

Nick Hedderman demonstrates some of the new features coming in Mango.
Communications


Apps


Web

If you've built Windows Phone or Windows Store apps you can cross-promote them with AdDuplex to get more users.

Wednesday, May 25, 2011

Move aside and let the MANGO through!

If you're interested in Windows Phone 7 development and were offline, for whatever reason, today or have been sleeping under a rock, you may have missed that the Beta version of the next version of the Windows Phone 7 development tools (codename "Mango") were released today.


You can read more details at http://windowsteamblog.com/windows_phone/b/wpdev/archive/2011/05/24/developer-news-beta-mango-tools-available-today.aspx then get it from http://create.msdn.com/en-US/news/WPDT_7.1_Beta

Check out this video (sorry it's a bit wobbly-I hope you don't get sea sick watching it) to see what was said at the launch.


If you've built Windows Phone or Windows Store apps you can cross-promote them with AdDuplex to get more users.

Tuesday, May 03, 2011

WP7 OS Version numbers

For my own reference and because I couldn't find anywhere else where this had been documented. Here are the different OS Version numbers for each of the WP7 releases/updates.

7.0.7004.0 - Original public release
7.0.7008.0 - "Pre-Nodo" update (contained changes to support the NoDo update)
7.0.7390.0 - NoDo (No-Donuts) update (included performance improvements and cut and paste)
7.0.7392.0 - Security update

Update: See http://www.microsoft.com/windowsphone/en-us/howto/wp7/basics/update-history.aspx

If you've built Windows Phone or Windows Store apps you can cross-promote them with AdDuplex to get more users.