Tutorials

1. Introduction

In the first part of the article, I tried to describe what is RX Framework and what can be done with it. One thing I’ve missed to mention was how RX could be used for asynchronous service calls. Namely, this is the accent in the second part of the article. For those who missed the first part, you could read it here.

The demo source code could be downloaded from here.

I think some of you may have developed an application that requires a lot of roundtrips on the server to retrieve data to be displayed to the user. Every time your application goes to the server it may have to wait for long running query to end its works, perhaps because the data are extracted from an huge database. Then it have to download the data and finally display them onto the screen.

If you have already deal with this kind of interaction you should know that the two connection limit of the web browser can become evident. For some of you that are not aware of this limitation you have to know that due to the RFC 2616 specification, the compliant browsers have not to hammer the network and are limited to make only two simultaneous connections to the server (per domain).

Uploading and downloading images using a WCF service with Silverlight

Quite often, when browsing the web, we encounter a situation where we are required to upload a file. When I want to register myself on a forum, I often get the question if I want to upload an avatar. Or when using a social networking site such as Facebook, I can upload pictures of me doing something that probably no one is interested in. The point I’m trying to make here is that when developing in Silverlight, we’ll also come in a situation where we want our users to upload files such as images to the server.

Introduction

One of the things I found missing in the current Bing Maps product is the possibility to create an elevation surface profile of routes. Perhaps this feature may not seem much on demand but actually affects more people than expected. Think for example about sports events like marathons and cycling races: to see a preview of the elevation profile of the trail would be of great benefit to the participants. But even if you're just simple hikers you might want to know what is the difference in level of your walking or bicycle trip to better understand the effort that it would entail.

1. Introduction

Beta versions of Silverlight 4 and .NET Framework 4 are already a fact. There are just a few weeks until the official releases. One of the coolest features which will be part of .NET Framework 4 and also will be available for Silverlight applications is the RX Framework. The arising interest around the RX Framework made me roll up my sleeves and start playing around this.
So the first step was to answer several important questions such as: “what is Linq to Events?”, “what is RX Framework?”, and “what is Reactive Programming?” And generally what lies behind these sound terms? Linq to events or RX Framework (also known as Reactive Extensions for .NET Framework) is one and the same designation for a library for composing asynchronous and event-based programs using observable collections.

One important thing to keep in mind when internationalizing your application is that things may not look the same in another language, and I’m not just referring to the text looking different.

My app looks like junk!

I’ve seen mixed reports stating that in languages like German a UI designer should expect the text strings to be as much as 40-60% longer, or more. What that means is that UI that you have designed to lay out just perfectly in English may just go down the tubes when you switch to German.

Monitor Resolution

As you are developing your app you may have your monitor set to a resolution of 1600x1200, or higher.

Usually when we think of internationalization we think of the text that appears on the screen. However, it is important that you also think about dates, and perhaps images as well.

Dates

In the U.S. we get used to thinking of dates in terms of month, day and year, in that order. There are different ways of representing these (month name vs. number, 2 vs. 4-digit year, etc.) but it is important to recognize the fact that dates are not always represented the same way in other countries. For example, in England the day comes first and the month comes second.

As mentioned in the What is a .resx file and how should I us it? post, when you create a .resx file a corresponding .cs (or .vb) file/class is code-generated, and this class gives you strongly-typed access to resources. This can be used in declarative databinding or in code. One important thing to understand however is that if you create a .resx file called MyStrings.resx, behind the scenes a class is created called MyStrings. So make sure when you name your .resx files that you don’t use a name that you have used for another class in your project!

Naming conventions for .resx keys

From what I’ve read, Microsoft’s recommendation for .resx keys is Pascal-case.

It’s about time for a step by step walkthrough of the internationalization process. For this example, I will use my preferred approach, MVVM. Note that most of the steps would be the same for other internationalization methods that I outlined in my previous post, Implementation Options.

Scenario

In this example we will pretend that we are tasked with building an application whose requirements state that the default language will be English, but that users will also be accessing it from the U.K. and Germany.

Note that this example is build with VisualStudio Beta 2 targeting Silverlight 4.

Most developers would prefer to hear that “this is the right way to do Internationalization”, but as with just about anything in the software development world, there are several different ways to do it. The standard response to the “what is the right way?” question is “it depends”. None of these methods are ‘right’ or ‘wrong’, but they do each have their pros and cons. Here are just some of the options:

Method 1 - Microsoft Silverlight Business Application

You may want to create a new project in VisualStudio using this template just to see how it’s done.