动态设置TextBlock的文本绑定

Question

I am attempting to write a multilingual application in Silverlight 4.0 and I at the point where I can start replacing my static text with dynamic text from a SampleData xaml file. Here is what I have:

My Database

<SampleData:something xmlns:SampleData="clr-namespace:Expression.Blend.SampleData.MyDatabase" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
  <SampleData:something.mysystemCollection>
    <SampleData:mysystem ID="1" English="Menu" German="Menü" French="Menu" Spanish="Menú" Swedish="Meny" Italian="Menu" Dutch="Menu" />
  </SampleData:something.mysystemCollection>
</SampleData:something>

My UserControl

<UserControl
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" mc:Ignorable="d"
    x:Class="Something.MyUC" d:DesignWidth="1000" d:DesignHeight="600">
    <Grid x:Name="LayoutRoot" DataContext="{Binding Source={StaticResource MyDatabase}}">
        <Grid Height="50" Margin="8,20,8,0" VerticalAlignment="Top" d:DataContext="{Binding mysystemCollection[1]}" x:Name="gTitle">
            <TextBlock x:Name="Title" Text="{Binding English}" TextWrapping="Wrap" Foreground="#FF00A33D" TextAlignment="Center" FontSize="22"/>
        </Grid>
    </Grid>
</UserControl>

As you can see, I have 7 languages that I want to deal with. Right now this loads the English version of my text just fine. I have spent the better part of today trying to figure out how to change the binding in my code to swap this out when I needed (lets say when I change the language via drop down).

Answer 1

It sounds like you're looking for code like this:

Title.SetBinding(TextProperty, new Binding { Path = new PropertyPath(language) });

All it does is create a new Binding for the language you requested and use it to replace the old binding for the Title's Text property.

Answer 2

You are going about this the wrong way. Best practice for localization in Silverlight is to use resource files holding the translated keywords. Here is some more info about this:

http://msdn.microsoft.com/en-us/library/cc838238%28VS.95%29.aspx

EDIT:

Here is an example where I use a helper class to hold the translated strings. These translations could then be loaded from just about anywhere. Static resource files, xml, database or whatever. I made this in a hurry, so it is not very stable. And it only switches between english and swedish.

XAML:

<UserControl x:Class="SilverlightApplication13.MainPage"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
             xmlns:local="clr-namespace:SilverlightApplication13"
             mc:Ignorable="d"
             d:DesignWidth="640"
             d:DesignHeight="480">

    <UserControl.Resources>
        <local:TranslationHelper x:Key="TranslationHelper"></local:TranslationHelper>
    </UserControl.Resources>

    <Grid x:Name="LayoutRoot">
        <StackPanel>

            <TextBlock Margin="10"
                       Text="{Binding Home, Source={StaticResource TranslationHelper}}"></TextBlock>

            <TextBlock Margin="10"
                       Text="{Binding Contact, Source={StaticResource TranslationHelper}}"></TextBlock>

            <TextBlock Margin="10"
                       Text="{Binding Links, Source={StaticResource TranslationHelper}}"></TextBlock>

            <Button Content="English"
                    HorizontalAlignment="Left"
                    Click="BtnEnglish_Click"
                    Margin="10"></Button>

            <Button Content="Swedish"
                    HorizontalAlignment="Left"
                    Click="BtnSwedish_Click"
                    Margin="10"></Button>
        </StackPanel>
    </Grid>
</UserControl>

Code-behind + TranslationHelper class:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using System.Windows.Threading;
using System.ComponentModel;

namespace SilverlightApplication13
{
    public partial class MainPage : UserControl
    {
        public MainPage()
        {
            InitializeComponent();

            //Default
            (this.Resources["TranslationHelper"] as TranslationHelper).SetLanguage("en-US");
        }

        private void BtnEnglish_Click(object sender, RoutedEventArgs e)
        {
            (this.Resources["TranslationHelper"] as TranslationHelper).SetLanguage("en-US");
        }

        private void BtnSwedish_Click(object sender, RoutedEventArgs e)
        {
            (this.Resources["TranslationHelper"] as TranslationHelper).SetLanguage("sv-SE");
        }
    }

    public class TranslationHelper : INotifyPropertyChanged
    {
        private string _Contact;

        /// <summary>
        /// Contact Property
        /// </summary>
        public string Contact
        {
            get { return _Contact; }
            set
            {
                _Contact = value;
                OnPropertyChanged("Contact");
            }
        }

        private string _Links;

        /// <summary>
        /// Links Property
        /// </summary>
        public string Links
        {
            get { return _Links; }
            set
            {
                _Links = value;
                OnPropertyChanged("Links");
            }
        }

        private string _Home;

        /// <summary>
        /// Home Property
        /// </summary>
        public string Home
        {
            get { return _Home; }
            set
            {
                _Home = value;
                OnPropertyChanged("Home");
            }
        }



        public TranslationHelper()
        {
            //Default
            SetLanguage("en-US");
        }

        public void SetLanguage(string cultureName)
        {
            //Hard coded values, need to be loaded from db or elsewhere

            switch (cultureName)
            {
                case "sv-SE":
                    Contact = "Kontakt";
                    Links = "Länkar";
                    Home = "Hem";
                    break;

                case "en-US":
                    Contact = "Contact";
                    Links = "Links";
                    Home = "Home";
                    break;

                default:
                    break;
            }
        }

        public event PropertyChangedEventHandler PropertyChanged;

        protected virtual void OnPropertyChanged(string propertyName)
        {
            if (PropertyChanged != null)
            {
                PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
            }
        }
    }
}