feature: multi-language supported

Pixiview/App.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
+using Pixiview.Resources;
 using Pixiview.UI.Theme;
 using Pixiview.Utils;
 using Xamarin.Forms;
@@ -11,16 +12,11 @@ namespace Pixiview
     {
         // public properties
         public static Theme CurrentTheme { get; private set; }
+        public static PlatformCulture CurrentCulture { get; private set; }
         public static Dictionary<string, object> ExtraResources { get; private set; }
 
-        public App()
+        private void InitResources(IEnvironmentService service)
         {
-            InitResources();
-        }
-
-        private void InitResources()
-        {
-            var service = DependencyService.Get<IEnvironmentService>();
             var p = service.GetEnvironment();
 
             ExtraResources = new Dictionary<string, object>
@@ -36,6 +32,13 @@ namespace Pixiview
             SetTheme(theme, true);
         }
 
+        private void InitLanguage(IEnvironmentService service)
+        {
+            var ci = service.GetCurrentCultureInfo();
+            service.SetCultureInfo(ci);
+            CurrentCulture = new PlatformCulture(ci.Name.ToLower());
+        }
+
         private void SetTheme(Theme theme, bool force = false)
         {
             if (force || theme != CurrentTheme)
@@ -62,6 +65,10 @@ namespace Pixiview
 
         protected override void OnStart()
         {
+            var service = DependencyService.Get<IEnvironmentService>();
+            InitResources(service);
+            InitLanguage(service);
+
             MainPage = UIFactory.CreateNavigationPage(new MainPage());
         }
 

Pixiview/MainPage.xaml

@@ -5,13 +5,14 @@
                xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
                xmlns:u="clr-namespace:Pixiview.UI"
                xmlns:util="clr-namespace:Pixiview.Utils"
+               xmlns:r="clr-namespace:Pixiview.Resources"
                mc:Ignorable="d"
                x:Class="Pixiview.MainPage"
                BackgroundColor="{DynamicResource WindowColor}"
                OrientationChanged="Page_OrientationChanged"
                util:StatusBar.StatusBarStyle="{DynamicResource StatusBarStyle}">
     <NavigationPage.TitleView>
-        <u:NavigationTitle Title="Follow"
+        <u:NavigationTitle Title="{r:Text Follow}"
                            IsLeftButtonVisible="True"
                            LeftButtonClicked="NavigationTitle_LeftButtonClicked"
                            RightButtonClicked="NavigationTitle_RightButtonClicked"/>

Pixiview/Pixiview.csproj

@@ -19,5 +19,13 @@
     <Folder Include="UI\" />
     <Folder Include="Utils\" />
     <Folder Include="UI\Theme\" />
+    <Folder Include="Resources\" />
+    <Folder Include="Resources\Languages\" />
+  </ItemGroup>
+  <ItemGroup>
+    <None Remove="Resources\Languages\zh-CN.xml" />
+  </ItemGroup>
+  <ItemGroup>
+    <EmbeddedResource Include="Resources\Languages\zh-CN.xml" />
   </ItemGroup>
 </Project>

Pixiview/Resources/Languages/zh-CN.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<root>
+    <Follow>已关注</Follow>
+</root>

Pixiview/Resources/PlatformCulture.cs

@@ -0,0 +1,43 @@
+namespace Pixiview.Resources
+{
+    public class PlatformCulture
+    {
+        public string PlatformString { get; private set; }
+        public string LanguageCode { get; private set; }
+        public string LocaleCode { get; private set; }
+
+        public string Language
+        {
+            get { return string.IsNullOrEmpty(LocaleCode) ? LanguageCode : LanguageCode + "-" + LocaleCode; }
+        }
+
+        public PlatformCulture() : this(null) { }
+        public PlatformCulture(string cultureString)
+        {
+            if (string.IsNullOrEmpty(cultureString))
+            {
+                //throw new ArgumentNullException(nameof(cultureString), "Expected culture identieifer");
+                cultureString = "en";
+            }
+
+            PlatformString = cultureString.Replace('_', '-');
+            var index = PlatformString.IndexOf('-');
+            if (index > 0)
+            {
+                var parts = PlatformString.Split('-');
+                LanguageCode = parts[0];
+                LocaleCode = parts[parts.Length - 1];
+            }
+            else
+            {
+                LanguageCode = PlatformString;
+                LocaleCode = "";
+            }
+        }
+
+        public override string ToString()
+        {
+            return PlatformString;
+        }
+    }
+}

Pixiview/Resources/ResourceHelper.cs

@@ -0,0 +1,92 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Reflection;
+using System.Xml.Linq;
+using Xamarin.Forms;
+using Xamarin.Forms.Xaml;
+
+namespace Pixiview.Resources
+{
+    public class ResourceHelper
+    {
+        static readonly Dictionary<string, LanguageResource> dict = new Dictionary<string, LanguageResource>();
+
+        public static string GetResource(string name, params object[] args)
+        {
+            if (!dict.TryGetValue(App.CurrentCulture.PlatformString, out LanguageResource lang))
+            {
+                lang = new LanguageResource(App.CurrentCulture);
+                dict.Add(App.CurrentCulture.PlatformString, lang);
+            }
+
+            if (args == null || args.Length == 0)
+            {
+                return lang[name];
+            }
+            return string.Format(lang[name], args);
+        }
+
+        private class LanguageResource
+        {
+            private readonly Dictionary<string, string> strings;
+
+            public string this[string key]
+            {
+                get
+                {
+                    if (strings != null && strings.TryGetValue(key, out string val))
+                    {
+                        return val;
+                    }
+                    return key;
+                }
+            }
+
+            public LanguageResource(PlatformCulture lang)
+            {
+                try
+                {
+                    var assembly = IntrospectionExtensions.GetTypeInfo(typeof(LanguageResource)).Assembly;
+                    var names = assembly.GetManifestResourceNames();
+                    var name = names.FirstOrDefault(n
+                        => string.Equals(n, $"Pixiview.Resources.Languages.{lang.Language}.xml", StringComparison.OrdinalIgnoreCase)
+                        || string.Equals(n, $"Pixiview.Resources.Languages.{lang.LanguageCode}.xml", StringComparison.OrdinalIgnoreCase));
+                    if (name == null)
+                    {
+                        name = "Pixiview.Resources.Languages.zh-CN.xml";
+                    }
+                    XDocument xml;
+                    using (var stream = assembly.GetManifestResourceStream(name))
+                    {
+                        xml = XDocument.Load(stream);
+                    }
+                    strings = new Dictionary<string, string>();
+                    foreach (var ele in xml.Root.Elements())
+                    {
+                        strings[ele.Name.LocalName] = ele.Value;
+                    }
+                }
+                catch
+                {
+                    // load failed
+                }
+            }
+        }
+    }
+
+    [ContentProperty(nameof(Text))]
+    public class TextExtension : IMarkupExtension
+    {
+        public string Text { get; set; }
+
+        public object ProvideValue(IServiceProvider serviceProvider)
+        {
+            if (Text == null)
+            {
+                return string.Empty;
+            }
+            return ResourceHelper.GetResource(Text);
+        }
+    }
+}

Pixiview/Utils/IEnvironmentService.cs

@@ -1,12 +1,17 @@
-using Xamarin.Forms;
+using System.Globalization;
+using Xamarin.Forms;
 
 namespace Pixiview.Utils
 {
     public interface IEnvironmentService
     {
         EnvironmentParameter GetEnvironment();
+
         Theme GetApplicationTheme();
         void SetStatusBarColor(Color color);
+
+        CultureInfo GetCurrentCultureInfo();
+        void SetCultureInfo(CultureInfo ci);
     }
 
     public class EnvironmentParameter