Add quick and dirty WcfSample.Android application.

We have to wait for dotnet/sdk#491 (as per http://www.natemcmaster.com/blog/2017/03/09/vs2015-to-vs2017-upgrade/) until we get better support for Xamarin.Android projects in dotnet/sdk. For now the project is excluded from the build. Enthusiasts may reactivate it in VS - Build - Configuration Manager.

InfoCarrier.Core.sln

@@ -1,7 +1,7 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
 # Visual Studio 15
-VisualStudioVersion = 15.0.26730.16
+VisualStudioVersion = 15.0.27004.2005
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "InfoCarrier.Core", "src\InfoCarrier.Core\InfoCarrier.Core.csproj", "{6B24F793-C93B-4869-A99B-AC51EE2C82AF}"
 EndProject
@@ -15,9 +15,11 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "sample", "sample", "{4A57BB
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "WcfSample.Shared", "sample\WcfSample.Shared\WcfSample.Shared.csproj", "{4AF12B6E-9979-4146-86BC-F59F6D00E4A0}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "WcfSample.Server", "sample\WcfSample.Server\WcfSample.Server.csproj", "{C43F891C-7548-4E22-B0C6-A5E931BEC278}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "WcfSample.Server", "sample\WcfSample.Server\WcfSample.Server.csproj", "{C43F891C-7548-4E22-B0C6-A5E931BEC278}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "WcfSample.Client", "sample\WcfSample.Client\WcfSample.Client.csproj", "{27B10A37-901E-4A3E-A2E3-4B48C62F0EB9}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "WcfSample.Client", "sample\WcfSample.Client\WcfSample.Client.csproj", "{27B10A37-901E-4A3E-A2E3-4B48C62F0EB9}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "WcfSample.Android", "sample\WcfSample.Android\WcfSample.Android.csproj", "{A26F1176-705E-490A-ADE3-F8B12DE1D970}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
@@ -45,6 +47,8 @@ Global
 		{27B10A37-901E-4A3E-A2E3-4B48C62F0EB9}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{27B10A37-901E-4A3E-A2E3-4B48C62F0EB9}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{27B10A37-901E-4A3E-A2E3-4B48C62F0EB9}.Release|Any CPU.Build.0 = Release|Any CPU
+		{A26F1176-705E-490A-ADE3-F8B12DE1D970}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{A26F1176-705E-490A-ADE3-F8B12DE1D970}.Release|Any CPU.ActiveCfg = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -55,6 +59,7 @@ Global
 		{4AF12B6E-9979-4146-86BC-F59F6D00E4A0} = {4A57BB06-6B50-4CF8-A601-E5572247FB5F}
 		{C43F891C-7548-4E22-B0C6-A5E931BEC278} = {4A57BB06-6B50-4CF8-A601-E5572247FB5F}
 		{27B10A37-901E-4A3E-A2E3-4B48C62F0EB9} = {4A57BB06-6B50-4CF8-A601-E5572247FB5F}
+		{A26F1176-705E-490A-ADE3-F8B12DE1D970} = {4A57BB06-6B50-4CF8-A601-E5572247FB5F}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {ADB840D9-C641-42AF-907B-8FE9280E9A8D}

sample/WcfSample.Android/Assets/AboutAssets.txt

@@ -0,0 +1,19 @@
+Any raw assets you want to be deployed with your application can be placed in
+this directory (and child directories) and given a Build Action of "AndroidAsset".
+
+These files will be deployed with you package and will be accessible using Android's
+AssetManager, like this:
+
+public class ReadAsset : Activity
+{
+	protected override void OnCreate (Bundle bundle)
+	{
+		base.OnCreate (bundle);
+
+		InputStream input = Assets.Open ("my_asset.txt");
+	}
+}
+
+Additionally, some Android functions will automatically load asset files:
+
+Typeface tf = Typeface.CreateFromAsset (Context.Assets, "fonts/samplefont.ttf");

sample/WcfSample.Android/MainActivity.cs

@@ -0,0 +1,92 @@
+// Copyright (c) on/off it-solutions gmbh. All rights reserved.
+// Licensed under the MIT license. See license.txt file in the project root for license information.
+
+namespace WcfSample
+{
+    using System;
+    using System.Linq;
+    using System.Threading;
+    using System.Threading.Tasks;
+    using global::Android.App;
+    using global::Android.OS;
+    using global::Android.Widget;
+    using InfoCarrier.Core.Client;
+    using InfoCarrier.Core.Common;
+    using Microsoft.EntityFrameworkCore;
+
+    [Activity(Label = "WcfSample.Android", MainLauncher = true, Icon = "@mipmap/icon")]
+    public class MainActivity : Activity
+    {
+        protected override void OnCreate(Bundle savedInstanceState)
+        {
+            base.OnCreate(savedInstanceState);
+
+            // Set our view from the "main" layout resource
+            this.SetContentView(Resource.Layout.Main);
+
+            // Get our button from the layout resource,
+            // and attach an event to it
+            Button button = this.FindViewById<Button>(Resource.Id.myButton);
+
+            button.Click += this.Button_Click;
+        }
+
+        private async void Button_Click(object sender, EventArgs e)
+        {
+            var consoleTextView = this.FindViewById<TextView>(Resource.Id.textConsole);
+            void ConsoleWriteLine(string line)
+            {
+                consoleTextView.Text += $"{line}\n";
+            }
+
+            consoleTextView.Text = "";
+
+            try
+            {
+                string serverUrl = this.FindViewById<TextView>(Resource.Id.editServerUrl).Text;
+                var optionsBuilder = new DbContextOptionsBuilder();
+                optionsBuilder.UseInfoCarrierBackend(new WcfBackendXamarinImpl(serverUrl));
+                var options = optionsBuilder.Options;
+
+                // Select and update
+                using (var context = new BloggingContext(options))
+                {
+                    Post myBlogPost = await (
+                        from blog in context.Blogs
+                        from post in blog.Posts
+                        join owner in context.Users on blog.OwnerId equals owner.Id
+                        where owner.Name == "hi-its-me"
+                        where post.Title == "my-blog-post"
+                        select post).SingleAsync();
+
+                    ConsoleWriteLine($@"Blog post '{myBlogPost.Title}' is retrieved.");
+
+                    myBlogPost.CreationDate = DateTime.Now;
+                    await context.SaveChangesAsync();
+                    ConsoleWriteLine($@"CreationDate is set to '{myBlogPost.CreationDate}'.");
+                }
+            }
+            catch (Exception exception)
+            {
+                ConsoleWriteLine(exception.ToString());
+            }
+        }
+
+        // Xamarin.Android implementation of asynchronous WCF method calls is broken in a very
+        // weird way (throws no exception but just never executes the continuation after await).
+        // We have to simulate asynchrony by calling synchronous methods on the thread pool.
+        private class WcfBackendXamarinImpl : WcfBackendImpl
+        {
+            public WcfBackendXamarinImpl(string serverUrl)
+                : base (serverUrl)
+            {
+            }
+
+            public override async Task<QueryDataResult> QueryDataAsync(QueryDataRequest request, DbContext dbContext, CancellationToken cancellationToken)
+                => await Task.Run(() => this.QueryData(request, dbContext), cancellationToken);
+
+            public override async Task<SaveChangesResult> SaveChangesAsync(SaveChangesRequest request, CancellationToken cancellationToken)
+                => await Task.Run(() => this.SaveChanges(request), cancellationToken);
+        }
+    }
+}

sample/WcfSample.Android/Properties/AndroidManifest.xml

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android" 
+          android:versionCode="1" 
+          android:versionName="1.0" 
+          package="WcfSample.Android.WcfSample.Android">
+  <uses-sdk android:minSdkVersion="21" />
+  <application android:allowBackup="true" android:icon="@mipmap/icon" android:label="@string/app_name">
+  </application>
+</manifest>

sample/WcfSample.Android/Properties/AssemblyInfo.cs

@@ -0,0 +1,31 @@
+// Copyright (c) on/off it-solutions gmbh. All rights reserved.
+// Licensed under the MIT license. See license.txt file in the project root for license information.
+
+using System.Reflection;
+using System.Runtime.InteropServices;
+
+// General Information about an assembly is controlled through the following
+// set of attributes. Change these attribute values to modify the information
+// associated with an assembly.
+[assembly: AssemblyTitle("WcfSample.Android")]
+[assembly: AssemblyDescription("")]
+[assembly: AssemblyConfiguration("")]
+[assembly: AssemblyCompany("")]
+[assembly: AssemblyProduct("WcfSample.Android")]
+[assembly: AssemblyCopyright("Copyright ©  2017")]
+[assembly: AssemblyTrademark("")]
+[assembly: AssemblyCulture("")]
+[assembly: ComVisible(false)]
+
+// Version information for an assembly consists of the following four values:
+//
+//      Major Version
+//      Minor Version
+//      Build Number
+//      Revision
+//
+// You can specify all the values or you can default the Build and Revision Numbers
+// by using the '*' as shown below:
+// [assembly: AssemblyVersion("1.0.*")]
+[assembly: AssemblyVersion("1.0.0.0")]
+[assembly: AssemblyFileVersion("1.0.0.0")]

sample/WcfSample.Android/Resources/AboutResources.txt

@@ -0,0 +1,44 @@
+Images, layout descriptions, binary blobs and string dictionaries can be included 
+in your application as resource files.  Various Android APIs are designed to 
+operate on the resource IDs instead of dealing with images, strings or binary blobs 
+directly.
+
+For example, a sample Android app that contains a user interface layout (main.axml),
+an internationalization string table (strings.xml) and some icons (drawable-XXX/icon.png) 
+would keep its resources in the "Resources" directory of the application:
+
+Resources/
+    drawable/
+        icon.png
+
+    layout/
+        main.axml
+
+    values/
+        strings.xml
+
+In order to get the build system to recognize Android resources, set the build action to
+"AndroidResource".  The native Android APIs do not operate directly with filenames, but 
+instead operate on resource IDs.  When you compile an Android application that uses resources, 
+the build system will package the resources for distribution and generate a class called "R" 
+(this is an Android convention) that contains the tokens for each one of the resources 
+included. For example, for the above Resources layout, this is what the R class would expose:
+
+public class R {
+    public class drawable {
+        public const int icon = 0x123;
+    }
+
+    public class layout {
+        public const int main = 0x456;
+    }
+
+    public class strings {
+        public const int first_string = 0xabc;
+        public const int second_string = 0xbcd;
+    }
+}
+
+You would then use R.drawable.icon to reference the drawable/icon.png file, or R.layout.main 
+to reference the layout/main.axml file, or R.strings.first_string to reference the first 
+string in the dictionary file values/strings.xml.

sample/WcfSample.Android/Resources/layout/Main.axml

@@ -0,0 +1,27 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:orientation="vertical"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent">
+    <TextView
+        android:text="Server URL"
+        android:textAppearance="?android:attr/textAppearanceLarge"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content" />
+    <EditText
+        android:text="10.0.2.2:8080"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:id="@+id/editServerUrl" />
+    <Button
+        android:id="@+id/myButton"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:text="@string/hello" />
+    <EditText
+        android:id="@+id/textConsole"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        android:scrollbars="vertical"
+        android:enabled="false" />
+</LinearLayout>

sample/WcfSample.Android/Resources/values/Strings.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+  <string name="hello">Hello World, Click Me!</string>
+  <string name="app_name">WcfSample.Android</string>
+</resources>