Localising your application

Some time ago, while working on an abandoned project (which, I have to admit honestly, turned out to be too laborious and complicated for me at that point) I had worked out a method to localise the program using XML files. That worked perfectly okay but only recently I have that there are way easiest methods to achieve that.
Let’s start with XML method. Available languages have a unique file with all strings stored in. The file is organised as follows:

As you can see each window has a specific section in XML file, and only this section will be loaded when a window is displayed. Every window has a method which loads all related strings:

Drawbacks of this method are clearly visible: you have to write a method which will load all strings from XML file. And you have to be extremely careful not to omit any text you want to display. It worked but not effectively at all.

There is other much simpler method which I found at AltControlDelete.pl. It uses resource files and System.Globalization. General idea is that you create individual *.resx file for each language: Lang.resx for default (English) language and Lang.xx-XX.resx, where xx-XX is the name of a culture (for instance, pl-PL for Polish). What’s important is that access modifier for those files must be set as public as shown below.

These files must be stored in one folder (let say “Languages”). Now, you need to include them in your source code and you’re ready to use these strings in your code:

To use it with XAML you need to add appropriate namespace to Window element in XAML file:

Now, to switch between languages you need to change Culture in your process:

Of course, you need to build your app in a way that user has the possibility to switch between languages as he intends.

That’s about it. The method with *.resx files is much simpler and most of all quicker and to some point less prone to omissions and mistakes. Of course, there are other methods (for instance, Mulitilingual app toolkit  from Microsoft) but this one seems to me that is easy enough and does not require any add-on or third-party software other than Visual Studio).

This post is based on articles available at www.altcontroldelete.pl by Jerzy Piechowiak.



More on dictionaries


Sometime ago I mentioned usage dictionaries to workaround lack of possibility to use variable which name is stored in another variable. It is useful trick (at least for me – beginner) but dictionaries may be employed to perform multitude of tasks. So, to preserve my newly gained skills I present most important aspects of dictionaries.

The main idea behind dictionaries is to have a structure that holds certain values tied to certain keys. It may be depicted as 1-D array which instead of numeric indexes uses any type of variables as example below shows:



Dictionary is a collection. To use it you need to include appropriate namespace: System.Collections.Generic. Definition of a dictionary must specify three things: its name, type of key and type of stored value:

The example below initialises empty dictionary – it was created using a constructor that doesn’t take any arguments. However, this is not the only option. Visual Studio suggest six different variations of constructor. You can set initial size of a dictionary, method of comparing keys – I am not going to describe each constructor as Visual Studio does that sufficiently. I just mention that it is possible to initialise a dictionary using a constructor that takes existing dictionary as an argument. Such action will copy of an argument dictionary to the newly created one. I find it most useful.



Adding new element
It is that simple that I was tempted to omit that, but for sake of conscientiousness here’s a quick example. To add a new element to a dictionary you need to use Add method and provide key and value of new element:

Accessing/modifying value of an element

Again, it’s very simple. Code below illustrates that:

Looping through whole dictionary
It is no secret that to run through whole dictionary you have to use foreach loop. To correctly design that loop you need to use KeyValuePair as an iterator. It is also necessary to provide types of keys and values accordingly to dictionary we want to loop through.

Other useful methods for dictionaries
Here are some other methods that you may find useful. These are quite simple operations so their description will be presented together with the code.



So, now we have basic comprehension of what dictionaries are and how to use them. I am sure you will easily find a task that which can utilise dictionaries. But to provide an example I’ll show one possible implementation.
Currently, I am writing an application which will allow user to switch between different languages (dictionaries, languages – that obvious, isn’t it?). The plan is to store language data in an XML file and load its content to a dictionary. Then, instead of hard-coding every word that is visible for end-user the program will display data stored in the dictionary. Here’s a class that allows that:

The class is static – there’s no need to create various instances as only one language can be displayed. The class has only one property – LoadedLanguage – a dictionary that uses string key to store string values.
There are two methods: method ExistLanguge(string) checks if a language file chosen by user exists. If it does the method returns true and the program continues. If the file doesn’t exist the program displays a warning message. Additionally, if the chosen language is English and its XML file doesn’t exist the program terminates as English is default language.
Another method is used to load specified language to the dictionary. As earlier said the language data is stored in the XML file. That XML file is divided into sections depending on which form it relates to.

Method LoadLanguage(string, string) takes as arguments language to load and section of XML file to load. Then it loops through the XML file and creates key/value pairs in the dictionary according to nodes present between specified area. Then these pairs are used in various parts of the program to display labels in specified language.

So, that quick guide through dictionaries would be it for today. Enjoy!

Examples (*.cs)