Added AsyncCommand example

README.md

@@ -28,6 +28,7 @@ The idea is that I want to use this repository as a lookup when facing different
     * [StringToSolidBrushConverter](xaml.experiences/resources/converters/stringsolidbrushconverter)
 * Commands
     * [DelegateCommand](xaml.experiences/resources/commands/delegatecommand)
+    * [AsyncCommand](xaml.experiences/resources/commands/asynccommand)
 * Helpers
     * [Observing objects](xaml.experiences/resources/helpers/observingobjects)
 

xaml.experiences/resources/commands/asynccommand/App.config

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<configuration>
+    <startup> 
+        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.6.1" />
+    </startup>
+</configuration>

xaml.experiences/resources/commands/asynccommand/App.xaml

@@ -0,0 +1,9 @@
+<Application x:Class="asynccommand.App"
+             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:local="clr-namespace:asynccommand"
+             StartupUri="MainWindow.xaml">
+    <Application.Resources>
+
+    </Application.Resources>
+</Application>

xaml.experiences/resources/commands/asynccommand/App.xaml.cs

@@ -0,0 +1,9 @@
+namespace asynccommand
+{
+    /// <summary>
+    /// Interaction logic for App.xaml
+    /// </summary>
+    public partial class App
+    {
+    }
+}

xaml.experiences/resources/commands/asynccommand/MainViewModel.cs

@@ -0,0 +1,44 @@
+using System.Threading.Tasks;
+using System.Windows.Input;
+using asynccommand.Resources;
+using asynccommand.Resources.Commands;
+using observingobjects;
+
+namespace asynccommand
+{
+    public class MainViewModel : BaseViewModel
+    {
+        private bool m_isBusy;
+        private string m_text;
+
+        public MainViewModel()
+        {
+            ChangeTextAsyncCommand = new AsyncCommand(ChangeTextAsync);
+        }
+
+        public ICommand ChangeTextAsyncCommand { get; }
+
+        public string Text
+        {
+            get => m_text;
+            set => SetProperty(ref m_text, value);
+        }
+
+        public bool IsBusy
+        {
+            get => m_isBusy;
+            set => SetProperty(ref m_isBusy, value);
+        }
+
+        private async Task ChangeTextAsync(object newText)
+        {
+            if (newText is string stringinput)
+            {
+                IsBusy = true;
+                await Task.Delay(4200);
+                Text = stringinput;
+                IsBusy = false;
+            }
+        }
+    }
+}

xaml.experiences/resources/commands/asynccommand/MainWindow.xaml

@@ -0,0 +1,40 @@
+<Window x:Class="asynccommand.MainWindow"
+        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:asynccommand"
+        xmlns:Converters="clr-namespace:markupextension.Resources.Converters;assembly=markupextension"
+        mc:Ignorable="d"
+        Title="MainWindow"
+        Height="350"
+        Width="525"
+        d:DataContext="{d:DesignInstance local:MainViewModel}" >
+    <Grid>
+        <Grid.RowDefinitions>
+            <RowDefinition />
+            <RowDefinition />
+        </Grid.RowDefinitions>
+        <!-- The button that runs the AsyncCommand -->
+        <Button Grid.Row="0"
+                Command="{Binding ChangeTextAsyncCommand}"
+                CommandParameter="Finished loading."
+                Visibility="{Binding ElementName=progressBar, Path=IsVisible, 
+                      Converter={Converters:BoolToVisibilityConverter Inverted=True}}"
+                Height="20"
+                Width="100"
+                Content="Click it"
+                HorizontalAlignment="Center" />
+        <!-- The progressbar that will be visible while the task is running -->
+        <ProgressBar Grid.Row="0"
+                     x:Name="progressBar"
+                     Height="20"
+                     Width="100"
+                     IsIndeterminate="True"
+                     Visibility="{Binding IsBusy, Converter={Converters:BoolToVisibilityConverter}}" />
+        <!-- The textblock that gets updated after the task is finished -->
+        <TextBlock Grid.Row="1"
+                   Text="{Binding Text}"
+                   HorizontalAlignment="Center" />
+    </Grid>
+</Window>

xaml.experiences/resources/commands/asynccommand/MainWindow.xaml.cs

@@ -0,0 +1,15 @@
+namespace asynccommand
+{
+    /// <summary>
+    /// Interaction logic for MainWindow.xaml
+    /// </summary>
+    public partial class MainWindow
+    {
+        public MainWindow()
+        {
+            InitializeComponent();
+
+            DataContext = new MainViewModel();
+        }
+    }
+}

xaml.experiences/resources/commands/asynccommand/Properties/AssemblyInfo.cs

@@ -0,0 +1,53 @@
+using System.Reflection;
+using System.Resources;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+using System.Windows;
+
+// 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("asynccommand")]
+[assembly: AssemblyDescription("")]
+[assembly: AssemblyConfiguration("")]
+[assembly: AssemblyCompany("")]
+[assembly: AssemblyProduct("asynccommand")]
+[assembly: AssemblyCopyright("Copyright ©  2019")]
+[assembly: AssemblyTrademark("")]
+[assembly: AssemblyCulture("")]
+
+// Setting ComVisible to false makes the types in this assembly not visible
+// to COM components.  If you need to access a type in this assembly from
+// COM, set the ComVisible attribute to true on that type.
+[assembly: ComVisible(false)]
+
+//In order to begin building localizable applications, set
+//<UICulture>CultureYouAreCodingWith</UICulture> in your .csproj file
+//inside a <PropertyGroup>.  For example, if you are using US english
+//in your source files, set the <UICulture> to en-US.  Then uncomment
+//the NeutralResourceLanguage attribute below.  Update the "en-US" in
+//the line below to match the UICulture setting in the project file.
+
+//[assembly: NeutralResourcesLanguage("en-US", UltimateResourceFallbackLocation.Satellite)]
+
+[assembly: ThemeInfo(
+    ResourceDictionaryLocation.None, //where theme specific resource dictionaries are located
+    //(used if a resource is not found in the page,
+    // or application resource dictionaries)
+    ResourceDictionaryLocation.SourceAssembly //where the generic resource dictionary is located
+    //(used if a resource is not found in the page,
+    // app, or any theme specific resource dictionaries)
+)]
+
+// 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")]

xaml.experiences/resources/commands/asynccommand/Properties/Resources.resx

@@ -0,0 +1,117 @@
+<?xml version="1.0" encoding="utf-8"?>
+<root>
+  <!-- 
+    Microsoft ResX Schema 
+    
+    Version 2.0
+    
+    The primary goals of this format is to allow a simple XML format 
+    that is mostly human readable. The generation and parsing of the 
+    various data types are done through the TypeConverter classes 
+    associated with the data types.
+    
+    Example:
+    
+    ... ado.net/XML headers & schema ...
+    <resheader name="resmimetype">text/microsoft-resx</resheader>
+    <resheader name="version">2.0</resheader>
+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>
+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>
+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>
+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>
+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">
+        <value>[base64 mime encoded serialized .NET Framework object]</value>
+    </data>
+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">
+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>
+        <comment>This is a comment</comment>
+    </data>
+                
+    There are any number of "resheader" rows that contain simple 
+    name/value pairs.
+    
+    Each data row contains a name, and value. The row also contains a 
+    type or mimetype. Type corresponds to a .NET class that support 
+    text/value conversion through the TypeConverter architecture. 
+    Classes that don't support this are serialized and stored with the 
+    mimetype set.
+    
+    The mimetype is used for serialized objects, and tells the 
+    ResXResourceReader how to depersist the object. This is currently not 
+    extensible. For a given mimetype the value must be set accordingly:
+    
+    Note - application/x-microsoft.net.object.binary.base64 is the format 
+    that the ResXResourceWriter will generate, however the reader can 
+    read any of the formats listed below.
+    
+    mimetype: application/x-microsoft.net.object.binary.base64
+    value   : The object must be serialized with 
+            : System.Serialization.Formatters.Binary.BinaryFormatter
+            : and then encoded with base64 encoding.
+    
+    mimetype: application/x-microsoft.net.object.soap.base64
+    value   : The object must be serialized with 
+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter
+            : and then encoded with base64 encoding.
+
+    mimetype: application/x-microsoft.net.object.bytearray.base64
+    value   : The object must be serialized into a byte array 
+            : using a System.ComponentModel.TypeConverter
+            : and then encoded with base64 encoding.
+    -->
+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
+    <xsd:element name="root" msdata:IsDataSet="true">
+      <xsd:complexType>
+        <xsd:choice maxOccurs="unbounded">
+          <xsd:element name="metadata">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" />
+              <xsd:attribute name="type" type="xsd:string" />
+              <xsd:attribute name="mimetype" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="assembly">
+            <xsd:complexType>
+              <xsd:attribute name="alias" type="xsd:string" />
+              <xsd:attribute name="name" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="data">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" msdata:Ordinal="1" />
+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="resheader">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" />
+            </xsd:complexType>
+          </xsd:element>
+        </xsd:choice>
+      </xsd:complexType>
+    </xsd:element>
+  </xsd:schema>
+  <resheader name="resmimetype">
+    <value>text/microsoft-resx</value>
+  </resheader>
+  <resheader name="version">
+    <value>2.0</value>
+  </resheader>
+  <resheader name="reader">
+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <resheader name="writer">
+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+</root>

xaml.experiences/resources/commands/asynccommand/Readme.md

@@ -0,0 +1,13 @@
+# AsyncCommand
+When designing applications one have to have the ability to run asynchronously methods. Running a `Task` that saves 
+the record in the database, or maybe validate your username when logging in to the application.
+
+Running asynchronously can also lead to a more responsive UI, as you can show a busy message while you wait for a 
+``Task`` to finish.
+
+[This command](Resources/Commands/AsyncCommand.cs) can be implemented to set up a ``ICommand`` that you can bind in Xaml to a run a 
+`Task`. The idea behind it is very much the same as the [``DelegateCommand``](../delegatecommand), except that this 
+will require a ``Func<object, Task>`` to be execute. 
+
+This will enable you to write beautiful [MVVM-Xaml](MainWindow.xaml), bound to [this](MainViewModel.cs).
+