add SplineGeometryKeyFrame

src/Shared/HandyControl_Shared/HandyControl_Shared.projitems

@@ -49,6 +49,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)Media\Animation\GeometryKeyFrame.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Media\Animation\GeometryKeyFrameCollection.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Media\Animation\LinearGeometryKeyFrame.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Media\Animation\SplineGeometryKeyFrame.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Tools\Converter\BorderCircularClipConverter.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Tools\Converter\ColLayoutConverter.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Tools\Converter\CornerRadiusSplitConverter.cs" />

src/Shared/HandyControl_Shared/Media/Animation/SplineGeometryKeyFrame.cs

@@ -0,0 +1,66 @@
+using System;
+using System.Windows;
+using System.Windows.Media;
+using System.Windows.Media.Animation;
+using HandyControl.Expression.Drawing;
+using HandyControl.Tools;
+
+namespace HandyControl.Media.Animation
+{
+    public class SplineGeometryKeyFrame : GeometryKeyFrame
+    {
+        private double[] _baseValues;
+
+        public SplineGeometryKeyFrame()
+        {
+
+        }
+
+        public SplineGeometryKeyFrame(Geometry value) : base(value)
+        {
+
+        }
+
+        public SplineGeometryKeyFrame(Geometry value, KeyTime keyTime) : base(value, keyTime)
+        {
+
+        }
+
+        public SplineGeometryKeyFrame(Geometry value, KeyTime keyTime, KeySpline keySpline) : base(value, keyTime)
+        {
+            KeySpline = keySpline ?? throw new ArgumentNullException(nameof(keySpline));
+        }
+
+        protected override Freezable CreateInstanceCore() => new SplineGeometryKeyFrame();
+
+        protected override Geometry InterpolateValueCore(Geometry baseValue, double keyFrameProgress)
+        {
+            if (_baseValues == null)
+            {
+                AnimationHelper.DecomposeGeometryStr(baseValue.ToString(), out _baseValues);
+            }
+
+            if (MathHelper.IsVerySmall(keyFrameProgress))
+            {
+                return baseValue;
+            }
+
+            if (MathHelper.AreClose(keyFrameProgress, 1))
+            {
+                return AnimationHelper.ComposeGeometry(Strings, Value);
+            }
+
+            var splineProgress = KeySpline.GetSplineProgress(keyFrameProgress);
+            return AnimationHelper.InterpolateGeometry(_baseValues, Value, splineProgress, Strings);
+        }
+
+        public static readonly DependencyProperty KeySplineProperty = DependencyProperty.Register(
+            "KeySpline", typeof(KeySpline), typeof(SplineGeometryKeyFrame), new PropertyMetadata(new KeySpline()));
+
+        public KeySpline KeySpline
+        {
+            get => (KeySpline) GetValue(KeySplineProperty);
+            set => SetValue(KeySplineProperty, value);
+        }
+    }
+}