small improvements

Azaion.Common/Controls/CanvasEditor.cs

@@ -346,6 +346,7 @@ public class CanvasEditor : Canvas
         _lastPos = e.GetPosition(this);
         _curRec = (Rectangle)sender;
         _curAnn = (DetectionControl)((Grid)_curRec.Parent).Parent;
+        (sender as UIElement)?.CaptureMouse();
         e.Handled = true;
     }
     

Azaion.Common/Controls/DetectionControl.cs

@@ -16,7 +16,6 @@ public class DetectionControl : Border
 
     private readonly Grid _grid;
     private readonly DetectionLabelPanel _detectionLabelPanel;
-    //private readonly Label _detectionLabel;
     public readonly Canvas DetectionLabelContainer;
 
     public TimeSpan Time { get; set; }
@@ -154,6 +153,7 @@ public class DetectionControl : Border
             Name = name,
         };
         rect.MouseDown += (sender, args) => _resizeStart(sender, args);
+        rect.MouseUp += (sender, args) => { (sender as UIElement)?.ReleaseMouseCapture(); };
         return rect;
     }