remove warnings

Azaion.Annotator/Controls/AnnotationControl.cs

@@ -14,8 +14,8 @@ public class AnnotationControl : Border
 
     private readonly Grid _grid;
     private readonly TextBlock _classNameLabel;
-    
-    private AnnotationClass _annotationClass;
+
+    private AnnotationClass _annotationClass = null!;
     public AnnotationClass AnnotationClass
     {
         get => _annotationClass;

Azaion.Annotator/Controls/CanvasEditor.cs

@@ -22,15 +22,15 @@ public class CanvasEditor : Canvas
     private readonly Line _verticalLine;
     private readonly TextBlock _classNameHint;
     
-    private Rectangle _curRec;
-    private AnnotationControl _curAnn;
+    private Rectangle _curRec = new();
+    private AnnotationControl _curAnn = null!;
     
     private const int MIN_SIZE = 20;
-    
-    public FormState FormState { get; set; }
-    public IMediator Mediator { get; set; }
 
-    private AnnotationClass _currentAnnClass; 
+    public FormState FormState { get; set; } = null!;
+    public IMediator Mediator { get; set; } = null!;
+
+    private AnnotationClass _currentAnnClass = null!;
     public AnnotationClass CurrentAnnClass
     {
         get => _currentAnnClass; 

Azaion.Annotator/Controls/UpdatableProgressBar.cs

@@ -7,7 +7,7 @@ namespace Azaion.Annotator.Controls
     {
         public delegate void ValueChange(double oldValue, double newValue);
 
-        public event ValueChange? ValueChanged;
+        public new event ValueChange? ValueChanged;
 
         public UpdatableProgressBar() : base()
         {