Add support for uppercase image extension (#770)

Author: tsvietOK

Files/BaseLayout.cs

@@ -221,15 +221,18 @@ public void RightClickContextMenu_Opening(object sender, object e)
                 {
                     var selectedDataItem = selectedFileSystemItems[0] as ListedItem;
 
-                    if (selectedDataItem.FileExtension.Equals(".zip", StringComparison.OrdinalIgnoreCase))
+                    if (!string.IsNullOrEmpty(selectedDataItem.FileExtension))
                     {
-                        UnloadMenuFlyoutItemByName("OpenItem");
-                        this.FindName("UnzipItem");
-                    }
-                    else if (!selectedDataItem.FileExtension.Equals(".zip", StringComparison.OrdinalIgnoreCase))
-                    {
-                        this.FindName("OpenItem");
-                        UnloadMenuFlyoutItemByName("UnzipItem");
+                        if (selectedDataItem.FileExtension.Equals(".zip", StringComparison.OrdinalIgnoreCase))
+                        {
+                            UnloadMenuFlyoutItemByName("OpenItem");
+                            this.FindName("UnzipItem");
+                        }
+                        else if (!selectedDataItem.FileExtension.Equals(".zip", StringComparison.OrdinalIgnoreCase))
+                        {
+                            this.FindName("OpenItem");
+                            UnloadMenuFlyoutItemByName("UnzipItem");
+                        }
                     }
                 }
                 else if (selectedFileSystemItems.Count > 1)

Files/View Models/InteractionViewModel.cs

@@ -53,7 +53,11 @@ public void CheckForImage()
             {
                 string ItemExtension = (App.CurrentInstance.ContentPage as BaseLayout).SelectedItem.FileExtension;
 
-                if (ItemExtension == ".png" || ItemExtension == ".jpg" || ItemExtension == ".bmp" || ItemExtension == ".jpeg")
+                if (!string.IsNullOrEmpty(ItemExtension)
+                    && ItemExtension.Equals(".png", StringComparison.OrdinalIgnoreCase)
+                    || ItemExtension.Equals(".jpg", StringComparison.OrdinalIgnoreCase)
+                    || ItemExtension.Equals(".bmp", StringComparison.OrdinalIgnoreCase)
+                    || ItemExtension.Equals(".jpeg", StringComparison.OrdinalIgnoreCase))
                 {
                     // Since item is an image, set the IsSelectedItemImage property to true
                     App.InteractionViewModel.IsSelectedItemImage = true;