diff --git a/src/Avalonia.Base/Data/BindingOperations.cs b/src/Avalonia.Base/Data/BindingOperations.cs
index 9170fbfaa06..b0a97e5c000 100644
--- a/src/Avalonia.Base/Data/BindingOperations.cs
+++ b/src/Avalonia.Base/Data/BindingOperations.cs
@@ -101,6 +101,25 @@ public static IDisposable Apply(
return Apply(target, property, binding);
}
+ ///
+ /// Retrieves the that is currently active on the
+ /// specified property.
+ ///
+ ///
+ /// The from which to retrieve the binding expression.
+ ///
+ ///
+ /// The binding target property from which to retrieve the binding expression.
+ ///
+ ///
+ /// The object that is active on the given property or
+ /// null if no binding expression is active on the given property.
+ ///
+ public static BindingExpressionBase? GetBindingExpressionBase(AvaloniaObject target, AvaloniaProperty property)
+ {
+ return target.GetValueStore().GetExpression(property);
+ }
+
private sealed class TwoWayBindingDisposable : IDisposable
{
private readonly IDisposable _toTargetSubscription;
diff --git a/src/Avalonia.Base/PropertyStore/ValueStore.cs b/src/Avalonia.Base/PropertyStore/ValueStore.cs
index 67d176eceac..789383b860a 100644
--- a/src/Avalonia.Base/PropertyStore/ValueStore.cs
+++ b/src/Avalonia.Base/PropertyStore/ValueStore.cs
@@ -292,6 +292,42 @@ public T GetValue(StyledProperty property)
return property.GetDefaultValue(Owner);
}
+ public BindingExpressionBase? GetExpression(AvaloniaProperty property)
+ {
+ var evaluatedLocalValue = false;
+
+ bool TryGetLocalValue(out BindingExpressionBase? result)
+ {
+ if (!evaluatedLocalValue)
+ {
+ evaluatedLocalValue = true;
+
+ if (_localValueBindings?.TryGetValue(property.Id, out var o) == true)
+ {
+ result = o as BindingExpressionBase;
+ return true;
+ }
+ }
+
+ result = null;
+ return false;
+ }
+
+ for (var i = _frames.Count - 1; i >= 0; --i)
+ {
+ var frame = _frames[i];
+
+ if (frame.Priority > BindingPriority.LocalValue && TryGetLocalValue(out var localExpression))
+ return localExpression;
+
+ if (frame.TryGetEntryIfActive(property, out var entry, out _))
+ return entry as BindingExpressionBase;
+ }
+
+ TryGetLocalValue(out var e);
+ return e;
+ }
+
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static EffectiveValue CastEffectiveValue(EffectiveValue value)
{
diff --git a/tests/Avalonia.Base.UnitTests/Data/BindingOperationsTests.cs b/tests/Avalonia.Base.UnitTests/Data/BindingOperationsTests.cs
new file mode 100644
index 00000000000..ac39e2b56d3
--- /dev/null
+++ b/tests/Avalonia.Base.UnitTests/Data/BindingOperationsTests.cs
@@ -0,0 +1,147 @@
+using Avalonia.Controls;
+using Avalonia.Data;
+using Avalonia.Data.Converters;
+using Avalonia.Styling;
+using Avalonia.UnitTests;
+using Xunit;
+
+namespace Avalonia.Base.UnitTests.Data;
+
+public class BindingOperationsTests
+{
+ [Fact]
+ public void GetBindingExpressionBase_Returns_Null_When_Not_Bound()
+ {
+ var target = new Control();
+ var expression = BindingOperations.GetBindingExpressionBase(target, Control.TagProperty);
+ Assert.Null(expression);
+ }
+
+ [Theory]
+ [InlineData(BindingPriority.Animation)]
+ [InlineData(BindingPriority.LocalValue)]
+ [InlineData(BindingPriority.Style)]
+ [InlineData(BindingPriority.StyleTrigger)]
+ public void GetBindingExpressionBase_Returns_Expression_When_Bound(BindingPriority priority)
+ {
+ var data = new { Tag = "foo" };
+ var target = new Control { DataContext = data };
+ var binding = new Binding("Tag") { Priority = priority };
+ target.Bind(Control.TagProperty, binding);
+
+ var expression = BindingOperations.GetBindingExpressionBase(target, Control.TagProperty);
+ Assert.NotNull(expression);
+ }
+
+ [Fact]
+ public void GetBindingExpressionBase_Returns_Expression_When_Bound_Locally_With_Binding_Error()
+ {
+ // Target has no data context so binding will fail.
+ var target = new Control();
+ var binding = new Binding("Tag");
+ target.Bind(Control.TagProperty, binding);
+
+ var expression = BindingOperations.GetBindingExpressionBase(target, Control.TagProperty);
+ Assert.NotNull(expression);
+ }
+
+ [Fact]
+ public void GetBindingExpressionBase_Returns_Expression_When_Bound_To_MultiBinding()
+ {
+ var data = new { Tag = "foo" };
+ var target = new Control { DataContext = data };
+ var binding = new MultiBinding
+ {
+ Converter = new FuncMultiValueConverter