Replace new Binding with compiled bindings (#2747)

* Use compiled bindings.

* Fix code bindings.

Author: davidbritch

docs/fundamentals/data-binding/basic-bindings.md

@@ -148,7 +148,7 @@ The `BindingContext` property is an important component of data bindings, but it
 
 In this example, the <xref:Microsoft.Maui.Controls.Slider> is defined to control the `Scale` property of the <xref:Microsoft.Maui.Controls.Label>. For that reason, the <xref:Microsoft.Maui.Controls.Slider> is set for a range of -2 to 2.
 
-The code-behind file sets the binding with the `SetBinding` method, with the second argument being a constructor for the `Binding` class:
+The code-behind file sets the binding with the `SetBinding` method, with the second argument being a `Func` that gets the value of the `Slider`:
 
 ```csharp
 public partial class AlternativeCodeBindingPage : ContentPage
@@ -157,13 +157,11 @@ public partial class AlternativeCodeBindingPage : ContentPage
     {
         InitializeComponent();
 
-        label.SetBinding(Label.ScaleProperty, new Binding("Value", source: slider));
+        label.SetBinding(Label.ScaleProperty, static (Slider s) => s.Value, source: slider);
     }
 }
 ```
 
-The `Binding` constructor has 6 parameters, so the `source` parameter is specified with a named argument. The argument is the `slider` object.
-
 > [!NOTE]
 > The <xref:Microsoft.Maui.Controls.VisualElement> class also defines `ScaleX` and `ScaleY` properties, which can scale the <xref:Microsoft.Maui.Controls.VisualElement> differently in the horizontal and vertical directions.
 

docs/fundamentals/data-binding/multibinding.md

@@ -159,12 +159,12 @@ public class MultiBindingConverterCodePage : ContentPage
         {
             Bindings = new Collection<BindingBase>
             {
-                new Binding("Employee1.IsOver16"),
-                new Binding("Employee1.HasPassedTest"),
-                new Binding("Employee1.IsSuspended", converter: new InverterConverter())
+                Binding.Create(static (GroupViewModel vm) => vm.Employee1.IsOver16),
+                Binding.Create(static (GroupViewModel vm) => vm.Employee1.HasPassedTest),
+                Binding.Create(static (GroupViewModel vm) => vm.Employee1.IsSuspended, converter: new InverterConverter())
             },
             Converter = new AllTrueMultiConverter()
-        });
+        });        
 
         Title = "MultiBinding converter demo";
         Content = checkBox;
@@ -201,9 +201,9 @@ label.SetBinding(Label.TextProperty, new MultiBinding
 {
     Bindings = new Collection<BindingBase>
     {
-        new Binding("Employee1.Forename"),
-        new Binding("Employee1.MiddleName"),
-        new Binding("Employee1.Surname")
+        Binding.Create(static (GroupViewModel vm) => vm.Employee1.Forename),
+        Binding.Create(static (GroupViewModel vm) => vm.Employee1.MiddleName),
+        Binding.Create(static (GroupViewModel vm) => vm.Employee1.Surname)
     },
     StringFormat = "{0} {1} {2}"
 });

docs/platform-integration/snippets/shared_1/MediaPage.cs

@@ -17,7 +17,7 @@ public MediaPage()
         this.BindingContext = this;
 
         var imageControl = new Image();
-        imageControl.SetBinding(Image.SourceProperty, new Binding("ImageItem"));
+        imageControl.SetBinding(Image.SourceProperty, Binding.Create(static (ImageItem item) => item.ImageItem));
 
         Content = new VerticalStackLayout
         {
@@ -105,15 +105,15 @@ public void CancelSpeech()
     {
         if (cts?.IsCancellationRequested ?? true)
             return;
-        
+
         cts.Cancel();
     }
     //</speak_cancel>
 
 
     //<speak_queue>
     bool isBusy = false;
-    
+
     public void SpeakMultiple()
     {
         isBusy = true;
@@ -125,4 +125,4 @@ public void SpeakMultiple()
             .ContinueWith((t) => { isBusy = false; }, TaskScheduler.FromCurrentSynchronizationContext());
     }
     //</speak_queue>
-}
+}

docs/user-interface/controls/carouselview/interaction.md

@@ -55,7 +55,7 @@ The equivalent C# code is:
 
 ```csharp
 CarouselView carouselView = new CarouselView();
-carouselView.SetBinding(ItemsView.ItemsSourceProperty, "Monkeys");
+carouselView.SetBinding(ItemsView.ItemsSourceProperty, static (MonkeysViewModel vm) => vm.Monkeys);
 carouselView.CurrentItemChanged += OnCurrentItemChanged;
 ```
 
@@ -89,9 +89,9 @@ The equivalent C# code is:
 
 ```csharp
 CarouselView carouselView = new CarouselView();
-carouselView.SetBinding(ItemsView.ItemsSourceProperty, "Monkeys");
-carouselView.SetBinding(CarouselView.CurrentItemChangedCommandProperty, "ItemChangedCommand");
-carouselView.SetBinding(CarouselView.CurrentItemChangedCommandParameterProperty, new Binding("CurrentItem", source: RelativeBindingSource.Self));
+carouselView.SetBinding(ItemsView.ItemsSourceProperty, static (MonkeysViewModel vm) => vm.Monkeys);
+carouselView.SetBinding(CarouselView.CurrentItemChangedCommandProperty, static (MonkeysViewModel vm) => vm.ItemChangedCommand);
+carouselView.SetBinding(CarouselView.CurrentItemChangedCommandParameterProperty, Binding.Create(static (CarouselView cv) => cv.CurrentItem, source: RelativeBindingSource.Self));
 ```
 
 In this example, the `CurrentItemChangedCommand` property binds to the `ItemChangedCommand` property, passing the `CurrentItem` property value to it as an argument. The `ItemChangedCommand` can then respond to the current item changing, as required:
@@ -128,7 +128,7 @@ The equivalent C# code is:
 
 ```csharp
 CarouselView carouselView = new CarouselView();
-carouselView.SetBinding(ItemsView.ItemsSourceProperty, "Monkeys");
+carouselView.SetBinding(ItemsView.ItemsSourceProperty, static (MonkeysViewModel vm) => vm.Monkeys);
 carouselView.PositionChanged += OnPositionChanged;
 ```
 
@@ -162,9 +162,9 @@ The equivalent C# code is:
 
 ```csharp
 CarouselView carouselView = new CarouselView();
-carouselView.SetBinding(ItemsView.ItemsSourceProperty, "Monkeys");
-carouselView.SetBinding(CarouselView.PositionChangedCommandProperty, "PositionChangedCommand");
-carouselView.SetBinding(CarouselView.PositionChangedCommandParameterProperty, new Binding("Position", source: RelativeBindingSource.Self));
+carouselView.SetBinding(ItemsView.ItemsSourceProperty, static (MonkeysViewModel vm) => vm.Monkeys);
+carouselView.SetBinding(CarouselView.PositionChangedCommandProperty, static (MonkeysViewModel vm) => vm.PositionChangedCommand);
+carouselView.SetBinding(CarouselView.PositionChangedCommandParameterProperty, Binding.Create(static (CarouselView cv) => cv.Position, source: RelativeBindingSource.Self));
 ```
 
 In this example, the `PositionChangedCommand` property binds to the `PositionChangedCommand` property, passing the `Position` property value to it as an argument. The `PositionChangedCommand` can then respond to the position changing, as required:
@@ -194,8 +194,8 @@ The equivalent C# code is:
 
 ```csharp
 CarouselView carouselView = new CarouselView();
-carouselView.SetBinding(ItemsView.ItemsSourceProperty, "Monkeys");
-carouselView.SetBinding(CarouselView.CurrentItemProperty, "CurrentItem");
+carouselView.SetBinding(ItemsView.ItemsSourceProperty, static (MonkeysViewModel vm) => vm.Monkeys);
+carouselView.SetBinding(CarouselView.CurrentItemProperty, static (MonkeysViewModel vm) => vm.CurrentItem);
 ```
 
 > [!NOTE]
@@ -239,8 +239,8 @@ The equivalent C# code is:
 
 ```csharp
 CarouselView carouselView = new CarouselView();
-carouselView.SetBinding(ItemsView.ItemsSourceProperty, "Monkeys");
-carouselView.SetBinding(CarouselView.PositionProperty, "Position");
+carouselView.SetBinding(ItemsView.ItemsSourceProperty, static (MonkeysViewModel vm) => vm.Monkeys);
+carouselView.SetBinding(CarouselView.PositionProperty, static (MonkeysViewModel vm) => vm.Position);
 ```
 
 > [!NOTE]

docs/user-interface/controls/carouselview/populate-data.md

@@ -36,7 +36,7 @@ The equivalent C# code is:
 
 ```csharp
 CarouselView carouselView = new CarouselView();
-carouselView.SetBinding(ItemsView.ItemsSourceProperty, "Monkeys");
+carouselView.SetBinding(ItemsView.ItemsSourceProperty, static (MonkeysViewModel vm) => vm.Monkeys);
 ```
 
 In this example, the `ItemsSource` property data binds to the `Monkeys` property of the connected viewmodel.
@@ -92,21 +92,21 @@ The equivalent C# code is:
 
 ```csharp
 CarouselView carouselView = new CarouselView();
-carouselView.SetBinding(ItemsView.ItemsSourceProperty, "Monkeys");
+carouselView.SetBinding(ItemsView.ItemsSourceProperty, static (MonkeysViewModel vm) => vm.Monkeys);
 
 carouselView.ItemTemplate = new DataTemplate(() =>
 {
     Label nameLabel = new Label { ... };
-    nameLabel.SetBinding(Label.TextProperty, "Name");
+    nameLabel.SetBinding(Label.TextProperty, static (Monkey monkey) => monkey.Name);
 
     Image image = new Image { ... };
-    image.SetBinding(Image.SourceProperty, "ImageUrl");
+    image.SetBinding(Image.SourceProperty, static (Monkey monkey) => monkey.ImageUrl);
 
     Label locationLabel = new Label { ... };
-    locationLabel.SetBinding(Label.TextProperty, "Location");
+    locationLabel.SetBinding(Label.TextProperty, static (Monkey monkey) => monkey.Location);
 
     Label detailsLabel = new Label { ... };
-    detailsLabel.SetBinding(Label.TextProperty, "Details");
+    detailsLabel.SetBinding(Label.TextProperty, static (Monkey monkey) => monkey.Details);
 
     StackLayout stackLayout = new StackLayout();
     stackLayout.Add(nameLabel);
@@ -174,7 +174,7 @@ CarouselView carouselView = new CarouselView
 {
     ItemTemplate = new MonkeyDataTemplateSelector { ... }
 };
-carouselView.SetBinding(ItemsView.ItemsSourceProperty, "Monkeys");
+carouselView.SetBinding(ItemsView.ItemsSourceProperty, static (MonkeysViewModel vm) => vm.Monkeys);
 ```
 
 The `ItemTemplate` property is set to a `MonkeyDataTemplateSelector` object. The following example shows the `MonkeyDataTemplateSelector` class:
@@ -280,7 +280,7 @@ The equivalent C# code is:
 
 ```csharp
 CarouselView carouselView = new CarouselView();
-carouselView.SetBinding(ItemsView.ItemsSourceProperty, "Monkeys");
+carouselView.SetBinding(ItemsView.ItemsSourceProperty, static (MonkeysViewModel vm) => vm.Monkeys);
 
 carouselView.ItemTemplate = new DataTemplate(() =>
 {
@@ -294,17 +294,17 @@ carouselView.ItemTemplate = new DataTemplate(() =>
         IconImageSource = "favorite.png",
         BackgroundColor = Colors.LightGreen
     };
-    favoriteSwipeItem.SetBinding(MenuItem.CommandProperty, new Binding("BindingContext.FavoriteCommand", source: carouselView));
-    favoriteSwipeItem.SetBinding(MenuItem.CommandParameterProperty, ".");
+    favoriteSwipeItem.SetBinding(MenuItem.CommandProperty, Binding.Create(static (MonkeysViewModel vm) => vm.FavoriteCommand, source: carouselView.BindingContext);
+    favoriteSwipeItem.SetBinding(MenuItem.CommandParameterProperty, static (CarouselView cv) => cv.CurrentItem, source: carouselView);
 
     SwipeItem deleteSwipeItem = new SwipeItem
     {
         Text = "Delete",
         IconImageSource = "delete.png",
         BackgroundColor = Colors.LightPink
     };
-    deleteSwipeItem.SetBinding(MenuItem.CommandProperty, new Binding("BindingContext.DeleteCommand", source: carouselView));
-    deleteSwipeItem.SetBinding(MenuItem.CommandParameterProperty, ".");
+    deleteSwipeItem.SetBinding(MenuItem.CommandProperty, Binding.Create(static (MonkeysViewModel vm) => vm.DeleteCommand, source: carouselView.BindingContext);
+    deleteSwipeItem.SetBinding(MenuItem.CommandParameterProperty, static (CarouselView cv) => cv.CurrentItem, source: carouselView);
 
     swipeView.TopItems = new SwipeItems { favoriteSwipeItem };
     swipeView.BottomItems = new SwipeItems { deleteSwipeItem };
@@ -353,7 +353,7 @@ ICommand refreshCommand = new Command(() =>
 refreshView.Command = refreshCommand;
 
 CarouselView carouselView = new CarouselView();
-carouselView.SetBinding(ItemsView.ItemsSourceProperty, "Animals");
+carouselView.SetBinding(ItemsView.ItemsSourceProperty, static (AnimalsViewModel vm) => vm.Animals);
 refreshView.Content = carouselView;
 // ...
 ```
@@ -402,7 +402,7 @@ CarouselView carouselView = new CarouselView
     RemainingItemsThreshold = 2
 };
 carouselView.RemainingItemsThresholdReached += OnCollectionViewRemainingItemsThresholdReached;
-carouselView.SetBinding(ItemsView.ItemsSourceProperty, "Animals");
+carouselView.SetBinding(ItemsView.ItemsSourceProperty, static (AnimalsViewModel vm) => vm.Animals);
 ```
 
 In this code example, the `RemainingItemsThresholdReached` event fires when there are 2 items not yet scrolled to, and in response executes the `OnCollectionViewRemainingItemsThresholdReached` event handler:

docs/user-interface/controls/collectionview/populate-data.md

@@ -36,7 +36,7 @@ The equivalent C# code is:
 
 ```csharp
 CollectionView collectionView = new CollectionView();
-collectionView.SetBinding(ItemsView.ItemsSourceProperty, "Monkeys");
+collectionView.SetBinding(ItemsView.ItemsSourceProperty, static (MonkeysViewModel vm) => vm.Monkeys);
 ```
 
 In this example, the `ItemsSource` property data binds to the `Monkeys` property of the connected viewmodel.
@@ -90,7 +90,7 @@ The equivalent C# code is:
 
 ```csharp
 CollectionView collectionView = new CollectionView();
-collectionView.SetBinding(ItemsView.ItemsSourceProperty, "Monkeys");
+collectionView.SetBinding(ItemsView.ItemsSourceProperty, static (MonkeysViewModel vm) => vm.Monkeys);
 
 collectionView.ItemTemplate = new DataTemplate(() =>
 {
@@ -101,13 +101,13 @@ collectionView.ItemTemplate = new DataTemplate(() =>
     grid.ColumnDefinitions.Add(new ColumnDefinition { Width = GridLength.Auto });
 
     Image image = new Image { Aspect = Aspect.AspectFill, HeightRequest = 60, WidthRequest = 60 };
-    image.SetBinding(Image.SourceProperty, "ImageUrl");
+    image.SetBinding(Image.SourceProperty, static (Monkey monkey) => monkey.ImageUrl);
 
     Label nameLabel = new Label { FontAttributes = FontAttributes.Bold };
-    nameLabel.SetBinding(Label.TextProperty, "Name");
+    nameLabel.SetBinding(Label.TextProperty, static (Monkey monkey) => monkey.Name);
 
     Label locationLabel = new Label { FontAttributes = FontAttributes.Italic, VerticalOptions = LayoutOptions.End };
-    locationLabel.SetBinding(Label.TextProperty, "Location");
+    locationLabel.SetBinding(Label.TextProperty, static (Monkey monkey) => monkey.Location);
 
     Grid.SetRowSpan(image, 2);
 
@@ -172,7 +172,7 @@ CollectionView collectionView = new CollectionView
 {
     ItemTemplate = new MonkeyDataTemplateSelector { ... }
 };
-collectionView.SetBinding(ItemsView.ItemsSourceProperty, "Monkeys");
+collectionView.SetBinding(ItemsView.ItemsSourceProperty, static (MonkeysViewModel vm) => vm.Monkeys);
 ```
 
 The `ItemTemplate` property is set to a `MonkeyDataTemplateSelector` object. The following example shows the `MonkeyDataTemplateSelector` class:
@@ -237,7 +237,7 @@ The equivalent C# code is:
 
 ```csharp
 CollectionView collectionView = new CollectionView();
-collectionView.SetBinding(ItemsView.ItemsSourceProperty, "Monkeys");
+collectionView.SetBinding(ItemsView.ItemsSourceProperty, static (MonkeysViewModel vm) => vm.Monkeys);
 
 collectionView.ItemTemplate = new DataTemplate(() =>
 {
@@ -252,17 +252,17 @@ collectionView.ItemTemplate = new DataTemplate(() =>
         IconImageSource = "favorite.png",
         BackgroundColor = Colors.LightGreen
     };
-    favoriteSwipeItem.SetBinding(MenuItem.CommandProperty, new Binding("BindingContext.FavoriteCommand", source: collectionView));
-    favoriteSwipeItem.SetBinding(MenuItem.CommandParameterProperty, ".");
+    favoriteSwipeItem.SetBinding(MenuItem.CommandProperty, Binding.Create(static (MonkeysViewModel vm) => vm.FavoriteCommand, source: collectionView.BindingContext);
+    favoriteSwipeItem.SetBinding(MenuItem.CommandParameterProperty, static (CollectionView cv) => cv.SelectedItem, source: collectionView);
 
     SwipeItem deleteSwipeItem = new SwipeItem
     {
         Text = "Delete",
         IconImageSource = "delete.png",
         BackgroundColor = Colors.LightPink
     };
-    deleteSwipeItem.SetBinding(MenuItem.CommandProperty, new Binding("BindingContext.DeleteCommand", source: collectionView));
-    deleteSwipeItem.SetBinding(MenuItem.CommandParameterProperty, ".");
+    deleteSwipeItem.SetBinding(MenuItem.CommandProperty, Binding.Create(static (MonkeysViewModel vm) => vm.DeleteCommand, source: collectionView.BindingContext);
+    deleteSwipeItem.SetBinding(MenuItem.CommandParameterProperty, static (CollectionView cv) => cv.SelectedItem, source: collectionView);
 
     swipeView.LeftItems = new SwipeItems { favoriteSwipeItem, deleteSwipeItem };
     swipeView.Content = grid;    
@@ -304,7 +304,7 @@ ICommand refreshCommand = new Command(() =>
 refreshView.Command = refreshCommand;
 
 CollectionView collectionView = new CollectionView();
-collectionView.SetBinding(ItemsView.ItemsSourceProperty, "Animals");
+collectionView.SetBinding(ItemsView.ItemsSourceProperty, static (AnimalsViewModel vm) => vm.Animals);
 refreshView.Content = collectionView;
 // ...
 ```
@@ -355,7 +355,7 @@ CollectionView collectionView = new CollectionView
     RemainingItemsThreshold = 5
 };
 collectionView.RemainingItemsThresholdReached += OnCollectionViewRemainingItemsThresholdReached;
-collectionView.SetBinding(ItemsView.ItemsSourceProperty, "Animals");
+collectionView.SetBinding(ItemsView.ItemsSourceProperty, static (AnimalsViewModel vm) => vm.Animals);
 ```
 
 In this code example, the `RemainingItemsThresholdReached` event fires when there are 5 items not yet scrolled to, and in response executes the `OnCollectionViewRemainingItemsThresholdReached` event handler:

docs/user-interface/controls/picker.md

@@ -102,7 +102,7 @@ The equivalent C# code is:
 
 ```csharp
 Label monkeyNameLabel = new Label();
-monkeyNameLabel.SetBinding(Label.TextProperty, new Binding("SelectedItem", source: picker));
+monkeyNameLabel.SetBinding(Label.TextProperty, Binding.Create(static (Picker picker) => picker.SelectedItem, source: picker));
 ```
 
 In addition, an event handler can be executed when the `SelectedIndexChanged` event fires:
@@ -139,8 +139,8 @@ The equivalent C# code is shown below:
 
 ```csharp
 Picker picker = new Picker { Title = "Select a monkey" };
-picker.SetBinding(Picker.ItemsSourceProperty, "Monkeys");
-picker.ItemDisplayBinding = new Binding("Name");
+picker.SetBinding(Picker.ItemsSourceProperty, static (MonkeysViewModel vm) => vm.Monkeys);
+picker.ItemDisplayBinding = Binding.Create(static (Monkey monkey) => monkey.Name);
 ```
 
 In this example, the `ItemsSource` property data binds to the `Monkeys` property of the binding context, which returns an `IList<Monkey>` collection. The following code example shows the `Monkey` class, which contains four properties:
@@ -176,21 +176,21 @@ The equivalent C# code is:
 
 ```csharp
 Picker picker = new Picker { Title = "Select a monkey" };
-picker.SetBinding(Picker.ItemsSourceProperty, "Monkeys");
-picker.SetBinding(Picker.SelectedItemProperty, "SelectedMonkey");
-picker.ItemDisplayBinding = new Binding("Name");
+picker.SetBinding(Picker.ItemsSourceProperty, static (MonkeysViewModel vm) => vm.Monkeys);
+picker.SetBinding(Picker.SelectedItemProperty, static (MonkeysViewModel vm) => vm.SelectedMonkey);
+picker.ItemDisplayBinding = Binding.Create(static (Monkey monkey) => monkey.Name);
 
 Label nameLabel = new Label { ... };
-nameLabel.SetBinding(Label.TextProperty, "SelectedMonkey.Name");
+nameLabel.SetBinding(Label.TextProperty, static (MonkeysViewModel vm) => vm.SelectedMonkey.Name);
 
 Label locationLabel = new Label { ... };
-locationLabel.SetBinding(Label.TextProperty, "SelectedMonkey.Location");
+locationLabel.SetBinding(Label.TextProperty, static (MonkeysViewModel vm) => vm.SelectedMonkey.Location);
 
 Image image = new Image { ... };
-image.SetBinding(Image.SourceProperty, "SelectedMonkey.ImageUrl");
+image.SetBinding(Image.SourceProperty, static (MonkeysViewModel vm) => vm.SelectedMonkey.ImageUrl);
 
 Label detailsLabel = new Label();
-detailsLabel.SetBinding(Label.TextProperty, "SelectedMonkey.Details");
+detailsLabel.SetBinding(Label.TextProperty, static (MonkeysViewModel vm) => vm.SelectedMonkey.Details);
 ```
 
 The `SelectedItem` property data binds to the `SelectedMonkey` property of the binding context, which is of type `Monkey`. Therefore, when the user selects an item in the <xref:Microsoft.Maui.Controls.Picker>, the `SelectedMonkey` property will be set to the selected `Monkey` object. The `SelectedMonkey` object data is displayed in the user interface by <xref:Microsoft.Maui.Controls.Label> and <xref:Microsoft.Maui.Controls.Image> views.