Bind to method

CalcBinding/CalcBinding.cs

@@ -49,7 +49,16 @@ public override object ProvideValue(IServiceProvider serviceProvider)
 
             BindingBase resBinding;
 
-            if (sourcePropertiesPathesWithPositions.Count() == 1)
+			if (sourcePropertiesPathesWithPositions.Count == 1 && targetPropertyType == typeof(System.Windows.Input.ICommand) && expressionTemplate == "{0}()")
+			{
+				var methodName = sourcePropertiesPathesWithPositions.Single().Item1;
+
+				var targetProvider = (IProvideValueTarget)serviceProvider.GetService(typeof(IProvideValueTarget));
+				var targetObject = targetProvider.TargetObject as FrameworkElement;
+
+				return new DataContextMethodCommand(methodName, targetObject);
+			}
+            else if (sourcePropertiesPathesWithPositions.Count() == 1)
             {
                 var binding = new System.Windows.Data.Binding(sourcePropertiesPathesWithPositions.Single().Item1)
                 {

CalcBinding/CalcBinding.csproj

@@ -69,6 +69,7 @@
     <Reference Include="WindowsBase" />
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="DataContextMethodCommand.cs" />
     <Compile Include="CalcBinding.cs" />
     <Compile Include="CalcConverter.cs" />
     <Compile Include="BoolToVisibilityConverter.cs" />

CalcBinding/DataContextMethodCommand.cs

@@ -0,0 +1,34 @@
+using System;
+using System.Windows;
+using System.Windows.Input;
+
+namespace CalcBinding
+{
+	public class DataContextMethodCommand : ICommand
+	{
+		string _methodName;
+		FrameworkElement _targetObject;
+
+		public DataContextMethodCommand(string methodName, FrameworkElement targetObject)
+		{
+			_methodName = methodName;
+			_targetObject = targetObject;
+		}
+
+		public event EventHandler CanExecuteChanged;
+
+		public bool CanExecute(object parameter)
+		{
+			return true;
+		}
+
+		public void Execute(object parameter)
+		{
+			//get DataContext as late as possible to execute on the correct instance
+			var dataContext = _targetObject.DataContext;
+			var dataContextType = dataContext.GetType();
+			var dataContextMethod = dataContextType.GetMethod(_methodName);
+			dataContextMethod.Invoke(dataContext, null);
+		}
+	}
+}

Tests/CalcBindingSystemTests.cs

@@ -744,6 +744,36 @@ public void BindingToPropertyContainingDigits()
             );
         }
 
+		[TestMethod]
+		public void BindingToMethod()
+		{
+			var viewModel1 = new ExampleViewModel();
+			var viewModel2 = new ExampleViewModel();
+			Assert.IsFalse(viewModel1.ClickMethodInvoked);
+			Assert.IsFalse(viewModel2.ClickMethodInvoked);
+
+			var button = new Button();
+			button.DataContext = viewModel1;
+
+			var calcBinding = new CalcBinding.Binding("ClickMethod()");
+			var bindingExpression = calcBinding.ProvideValue(new ServiceProviderMock(button, Button.CommandProperty));
+
+			button.SetValue(Button.CommandProperty, bindingExpression);
+			var command = button.GetValue(Button.CommandProperty) as System.Windows.Input.ICommand;
+			command.Execute(null);
+
+			Assert.IsTrue(viewModel1.ClickMethodInvoked);
+			Assert.IsFalse(viewModel2.ClickMethodInvoked);
+
+			button.DataContext = viewModel2;
+			command = button.GetValue(Button.CommandProperty) as System.Windows.Input.ICommand;
+			command.Execute(null);
+
+			Assert.IsTrue(viewModel1.ClickMethodInvoked);
+			Assert.IsTrue(viewModel2.ClickMethodInvoked);
+		}
+
+
         #region Convert
 
         public void StringAndObjectBindingAssert(string path, INotifyPropertyChanged source,

WpfExample/ExampleViewModel.cs

@@ -170,6 +170,24 @@ public ConcreteViewModel2(int a)
     /// </summary>
     public class ExampleViewModel : BaseViewModel
     {
+		private bool clickMethodInvoked;
+		public bool ClickMethodInvoked
+		{
+			get { return clickMethodInvoked; }
+			set
+			{
+				clickMethodInvoked = value;
+
+				new object().TraceTime(
+					() => RaisePropertyChanged(() => ClickMethodInvoked)
+				);
+			}
+		}
+		public void ClickMethod()
+		{
+			ClickMethodInvoked = !ClickMethodInvoked;
+		}
+
         private double a = 10;
         public double A
         {

WpfExample/FifthPage.xaml

@@ -0,0 +1,20 @@
+<UserControl x:Class="WpfExample.FifthPage"
+        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:c="clr-namespace:CalcBinding;assembly=CalcBinding"
+        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+        mc:Ignorable="d"
+        d:Height="450" d:Width="825">
+
+	<Grid>
+		<Grid.RowDefinitions>
+			<RowDefinition Height="Auto"/>
+			<RowDefinition Height="Auto"/>
+			<RowDefinition/>
+		</Grid.RowDefinitions>
+		<CheckBox Grid.Row="0" Content="Button clicked" IsChecked="{Binding ClickMethodInvoked}" IsEnabled="False"/>
+		<Button Grid.Row="1" Content="Click" Command="{c:Binding ClickMethod()}"/>
+
+	</Grid>
+</UserControl>

WpfExample/FifthPage.xaml.cs

@@ -0,0 +1,28 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Data;
+using System.Windows.Documents;
+using System.Windows.Input;
+using System.Windows.Media;
+using System.Windows.Media.Imaging;
+using System.Windows.Navigation;
+using System.Windows.Shapes;
+
+namespace WpfExample
+{
+	/// <summary>
+	/// Interaction logic for FifthPage.xaml
+	/// </summary>
+	public partial class FifthPage : UserControl
+	{
+		public FifthPage()
+		{
+			InitializeComponent();
+		}
+	}
+}

WpfExample/MainWindow.xaml

@@ -14,10 +14,13 @@
             </TabItem>
             <TabItem Header="Math and inversed expressions">
                 <local:ThirdPage/>
-            </TabItem>
-            <TabItem Header="Null properties support">
-                <local:FourthPage/>
-            </TabItem>
-        </TabControl>
+			</TabItem>
+			<TabItem Header="Null properties support">
+				<local:FourthPage/>
+			</TabItem>
+			<TabItem Header="Commands">
+				<local:FifthPage/>
+			</TabItem>
+		</TabControl>
     </Grid>
 </Window>

WpfExample/WpfExample.csproj

@@ -76,6 +76,10 @@
       <Generator>MSBuild:Compile</Generator>
       <SubType>Designer</SubType>
     </ApplicationDefinition>
+    <Page Include="FifthPage.xaml">
+      <SubType>Designer</SubType>
+      <Generator>MSBuild:Compile</Generator>
+    </Page>
     <Page Include="FourthPage.xaml">
       <Generator>MSBuild:Compile</Generator>
       <SubType>Designer</SubType>
@@ -100,6 +104,9 @@
       <DependentUpon>App.xaml</DependentUpon>
       <SubType>Code</SubType>
     </Compile>
+    <Compile Include="FifthPage.xaml.cs">
+      <DependentUpon>FifthPage.xaml</DependentUpon>
+    </Compile>
     <Compile Include="FourthPage.xaml.cs">
       <DependentUpon>FourthPage.xaml</DependentUpon>
     </Compile>