add ImageAttach

src/Shared/HandyControlDemo_Shared/ViewModel/Main/ItemsDisplayViewModel.cs

@@ -7,12 +7,24 @@ namespace HandyControlDemo.ViewModel
 {
     public class ItemsDisplayViewModel : DemoViewModelBase<AvatarModel>
     {
-        public ItemsDisplayViewModel(Func<List<AvatarModel>> getDatAction)
+        public ItemsDisplayViewModel(Func<List<AvatarModel>> getDataAction)
         {
-#if NET40
-            Task.Factory.StartNew(() => DataList = getDatAction?.Invoke());
+#if !NET40
+            Task.Factory.StartNew(() => DataList = getDataAction?.Invoke()).ContinueWith(obj => DataGot = true);
 #else
-            Task.Run(() => DataList = getDatAction?.Invoke());
+            Task.Run(() => DataList = getDataAction?.Invoke()).ContinueWith(obj => DataGot = true);
+#endif
+        }
+
+        private bool _dataGot;
+
+        public bool DataGot
+        {
+            get => _dataGot;
+#if NET40
+            set => Set(nameof(DataGot), ref _dataGot, value);
+#else
+            set => Set(ref _dataGot, value);
 #endif
         }
     }