fix: fixed a measure issue of RelativePanel

src/Shared/HandyControl_Shared/Controls/Panel/RelativePanel.cs

@@ -417,10 +417,18 @@ public class RelativePanel : Panel
 
         public void Measure(Size availableSize)
         {
-            AvailableSize = availableSize;
+            AvailableSize = EnsureValidSize(availableSize);
             Measure(_nodeDic.Values, null);
         }
 
+        private static Size EnsureValidSize(Size size)
+        {
+            var width = double.IsInfinity(size.Width) ? 0 : size.Width;
+            var height = double.IsInfinity(size.Height) ? 0 : size.Height;
+
+            return new Size(width, height);
+        }
+
         private void Measure(IEnumerable<GraphNode> nodes, HashSet<DependencyObject> set)
         {
             set ??= new HashSet<DependencyObject>();