Issues

Finally we came to the editing part that concerns the DataGrid control in Silverlight 2. After we took a quick look at the control, learned how to make some basic customizations to it and defined the three types of columns available, now we're going to see how can we edit the information. The DataGrid control has an integrated editing functionality. By double-clicking on a cell you automatically go into edit mode for that cell. If you want to cancel the edit just press Esc and if you want to submit the changes press Enter or change the selection. The purpose of this article is to show how to use this functionality and combine it with some properties and events.

Introduction

Note: this article is specific for Silverlight 2 Beta 2.

What is Internationalization and localization?

Localization and internationalization are the processes of making software capable to display content in different languages depending on the user preferences like described in Wikipedia.

It's a common scenario in business applications to support multiple languages. Development environments often automate the process of internationalizing an application. For example Visual Studio can create local resources for an ASP.NET Page or User Control automatically and in the ASP.NET web application the proper localized strings can be loaded automatically depending on the user preferences without the need for the developer to implement all this functionality.

What about Internationalization and localization in Silverlight?

I spent a few hours in Internet looking for some resources which cover this topic. So I'll try to summarize the process of building an international Silverlight application and will give some examples.

Using RESX files

Introduction

We’ve introduced you to the basics of Custom Controls in our previous article. Now we will give another example this time involving the Visual States Manager. We will create a templatable ContentControl that uses animations on its Content and the States & Parts model proposed by Microsoft.

Dowload source code

Parts & States Model

The idea behind the States & Parts is to separate better the logic from the visual appearance and thus to allow better flexibility for both.

Introduction

Overview of sockets in general

"Found" an annoying little bug that I can't seem to get around while moving some Silverlight 1.1 code to Silverlight 2.0.

In this project, all of our controls have a base class that provides some common functionality.  In Silverlight 2.0, now that we have proper user controls and that wonderful InitializeComponent() method, I've been moving all our old style user controls to the proper method.

However, Silverlight generates a partial class where the InitializeComponentMethod() sits, and this class is regenerated every time you change some of the XAML.

I finally had time to sit down and really debug the Silverlight animation problem I described in a previous post.  I recommend heading over there and reading that post, it also displays the problem in action.

The issue is that when using the Height or MaxHeight properties to restrict a TextBlock, if the text is longer than is allowed by the defined size, even though visually the text is truncated, the area in which the text would be still responds to mouse actions.  It does not matter if the properties are set on a parent object like a StackPanel or on the TextBlock itself, the issue is the same.

Working with the Silverlight testing framework the last three weeks has been interesting.  I ran into a crazy intermittent bug which drove me made for about 2 hours.  The usercontrol that I was adding to the TestSurface would be visible about 50% of the time when running my tests. The test would still run and I could hear the audio portion of the videos that were playing as part of an integration test, but the Controls were not visible on the test surface.

In WPF, one of the best know effects is the "reflection" effect, where a scene reflects itself dynamically. It's a very cool feature, because it's really easy to realize, and it allows to reflect images, but also videos or other User Interface scenes. The key to this is to use a VisualBrush. Silverlight is not exactly as powerful as WPF, and doesn't have VisualBrush, but it has ImageBrush and VideoBrush, both of them allowing cool media reflection effects (these brushes can also be used for other things!).

The key to making a reflection is placing a picture (or a video), and underneath it, an element (typically a Border).

For some random reason, occasionally Silverlight 2 projects will suddenly no longer support debugging.  Very frustrating.  Fortunately, the fix is pretty simple:

Right click on the Web in the Solution Explorer pane.  If you have a Web project, you will see "Property Pages", if you have a Web Application project you will see "Properties".  Select that.

Under "Property Pages" select "Start Options" and make sure that both "Silverlight" and "ASP.NET" are checked, "Native Code" and "SQL Server" are unchecked.

As I've been neck-deep in Silverlight 2 for a couple of months now I noticed that there are some bugs/inconsistencies that aren't necessarily known to everyone. Here's a list of some of the issues (with workarounds if possible):

Custom Control Data Binding

If you are writing User/Custom Controls that want to be used in data binding (i.e. DataTemplate), you must use the assembly name in the namespace declaration, even if it is in the main assembly:

xmlns:my="clr-namespace:MyAssembly.Controls"

xmlns:my="clr-namespace:MyAssembly.Controls;assembly=MyAssembly"

This is a known bug that will be fixed in future builds.