Crashing your LightSwitch project with your extensions is a piece of cake. The first simplest thing I did was change the business type to handle integer values instead of string ones. But I changed “:String” to “:Int”. That was enough to do it. It should be “:Int32”.

So, after managing to create and use (declare as a type for an integer field in an entity) my business type, keeping my LightSwitch project in one piece, I had to work on my control. As I have already mentioned I had my custom control ready and tested, so, it should be easy.

I had used my custom control only in detail parts and although the expander used was “deforming” the layout when expanded (I have to fix this anyhow in the future) everything were going back to normal after collapsing the expander. This was not so for collections. Using my control in a grid the result after collapsing the color picker control was a grid row having a height of the expanded control. The reason is that the grid rows are auto-sized and have no specific...

I haven’t been able to post during the last week. It’s been a very hectic week and I didn’t have time or when I did have the time I didn’t have the courage…

Anyhow, I am going to share with you issues I had to face creating my first LightSwitch Extensions project.

First thing was to create the Color business type. I already had custom Silverlight control and value converters I had already published in a sample in MSDN’s LightSwitch Developer Center. So half of the work was done, right? Well, not quite…

I must say here that many of the problems were a result of the fact that editing the lsml file is very error prone as there is nothing to help you while editing the file by hand. I mean it’s not like editing the XAML of a Silverlight control, with code completion, syntax checking and all the goodies. It’s raw XML editing. And the thing with errors in lsml is that the result is terrifying…a tag improperly...

The Data Grid that is built-into LightSwitch is quite advanced. You will not really appreciate it until you attempt to duplicate its functionality manually. However, you may be faced with situations that require you to implement a Data Grid from scratch. This will allow you maximum flexibility in your application…

I had initially discarded LightSwitch from my deck of choices. At first glance (early Beta 1) I had misjudged it as poor relative of application builders that I hate altogether.

It was after watching Beth Massi’ s presentation in Tech-Ed USA 2011 regarding extensibility that made me take a second good look at it. And then…then it was love at second sight...

A strong point about ComponentOne is their ability to make great Silverlight controls that aggregate data. The LightSwitch Help Website previously covered their LightSwitch extension: Using OLAP for LightSwitch. That control is designed to be mostly configured by end-users. The article: The LightSwitch Control Extension Makers Dilemma...

It is important to know that you should only use the methods described here as a last resort. The methods described here should not be your first choice for implementing a custom Silverlight Control in LightSwitch. 99% of the time these other methods will work:

Creating A LightSwitch Custom Silverlight Control This Is How LightSwitch Does MVVM...