diff --git a/FileDbCache/WPF/FileDbCache.WPF.cs b/FileDbCache/WPF/FileDbCache.WPF.cs
index bf3ec8fa..56b4d955 100644
--- a/FileDbCache/WPF/FileDbCache.WPF.cs
+++ b/FileDbCache/WPF/FileDbCache.WPF.cs
@@ -147,9 +147,7 @@ namespace MapControl.Caching
                 throw new ArgumentNullException("The parameter key must not be null.");
             }
 
-            var imageCacheItem = value as ImageCacheItem;
-
-            if (imageCacheItem == null)
+            if (!(value is ImageCacheItem imageCacheItem))
             {
                 throw new ArgumentException("The parameter value must be a MapControl.Caching.ImageCacheItem instance.");
             }
diff --git a/MBTiles/Shared/MBTileLayer.cs b/MBTiles/Shared/MBTileLayer.cs
index 3133ea8f..95705204 100644
--- a/MBTiles/Shared/MBTileLayer.cs
+++ b/MBTiles/Shared/MBTileLayer.cs
@@ -57,26 +57,23 @@ namespace MapControl.MBTiles
             if (file != null)
             {
                 var tileData = await MBTileData.CreateAsync(file);
-                int minZoom;
-                int maxZoom;
-                string s;
 
-                if (tileData.Metadata.TryGetValue("name", out s))
+                if (tileData.Metadata.TryGetValue("name", out string sourceName))
                 {
-                    SourceName = s;
+                    SourceName = sourceName;
                 }
 
-                if (tileData.Metadata.TryGetValue("description", out s))
+                if (tileData.Metadata.TryGetValue("description", out string description))
                 {
-                    Description = s;
+                    Description = description;
                 }
 
-                if (tileData.Metadata.TryGetValue("minzoom", out s) && int.TryParse(s, out minZoom))
+                if (tileData.Metadata.TryGetValue("minzoom", out sourceName) && int.TryParse(sourceName, out int minZoom))
                 {
                     MinZoomLevel = minZoom;
                 }
 
-                if (tileData.Metadata.TryGetValue("maxzoom", out s) && int.TryParse(s, out maxZoom))
+                if (tileData.Metadata.TryGetValue("maxzoom", out sourceName) && int.TryParse(sourceName, out int maxZoom))
                 {
                     MaxZoomLevel = maxZoom;
                 }
diff --git a/MapControl/Shared/AzimuthalProjection.cs b/MapControl/Shared/AzimuthalProjection.cs
index 1b77cfe2..efdfb67f 100644
--- a/MapControl/Shared/AzimuthalProjection.cs
+++ b/MapControl/Shared/AzimuthalProjection.cs
@@ -16,16 +16,9 @@ namespace MapControl
     /// </summary>
     public abstract class AzimuthalProjection : MapProjection
     {
-        public override bool IsNormalCylindrical
-        {
-            get { return false; }
-        }
-
         public override Rect BoundingBoxToRect(BoundingBox boundingBox)
         {
-            var cbbox = boundingBox as CenteredBoundingBox;
-
-            if (cbbox != null)
+            if (boundingBox is CenteredBoundingBox cbbox)
             {
                 var center = LocationToMap(cbbox.Center);
 
diff --git a/MapControl/Shared/EquirectangularProjection.cs b/MapControl/Shared/EquirectangularProjection.cs
index 2ffd632c..5398afda 100644
--- a/MapControl/Shared/EquirectangularProjection.cs
+++ b/MapControl/Shared/EquirectangularProjection.cs
@@ -23,6 +23,11 @@ namespace MapControl
             CrsId = "EPSG:4326";
         }
 
+        public override bool IsNormalCylindrical
+        {
+            get { return true; }
+        }
+
         public override Vector GetRelativeScale(Location location)
         {
             return new Vector(
diff --git a/MapControl/Shared/MapBase.cs b/MapControl/Shared/MapBase.cs
index 0d2d131a..c452e6ba 100644
--- a/MapControl/Shared/MapBase.cs
+++ b/MapControl/Shared/MapBase.cs
@@ -388,8 +388,7 @@ namespace MapControl
             {
                 Children.Remove(oldLayer);
 
-                var mapLayer = oldLayer as IMapLayer;
-                if (mapLayer != null)
+                if (oldLayer is IMapLayer mapLayer)
                 {
                     if (mapLayer.MapBackground != null)
                     {
@@ -406,8 +405,7 @@ namespace MapControl
             {
                 Children.Insert(0, newLayer);
 
-                var mapLayer = newLayer as IMapLayer;
-                if (mapLayer != null)
+                if (newLayer is IMapLayer mapLayer)
                 {
                     if (mapLayer.MapBackground != null)
                     {
diff --git a/MapControl/Shared/MapPanel.cs b/MapControl/Shared/MapPanel.cs
index c554759e..a44f4c48 100644
--- a/MapControl/Shared/MapPanel.cs
+++ b/MapControl/Shared/MapPanel.cs
@@ -228,9 +228,7 @@ namespace MapControl
             element.Height = rect.Height;
             element.Arrange(rect);
 
-            var rotateTransform = element.RenderTransform as RotateTransform;
-
-            if (rotateTransform != null)
+            if (element.RenderTransform is RotateTransform rotateTransform)
             {
                 rotateTransform.Angle = parentMap.ViewTransform.Rotation;
             }
@@ -293,9 +291,7 @@ namespace MapControl
 
         private static void ParentMapPropertyChanged(DependencyObject obj, DependencyPropertyChangedEventArgs e)
         {
-            var mapElement = obj as IMapElement;
-
-            if (mapElement != null)
+            if (obj is IMapElement mapElement)
             {
                 mapElement.ParentMap = e.NewValue as MapBase;
             }
diff --git a/MapControl/Shared/MapProjection.cs b/MapControl/Shared/MapProjection.cs
index ab593779..cfe7eabb 100644
--- a/MapControl/Shared/MapProjection.cs
+++ b/MapControl/Shared/MapProjection.cs
@@ -37,7 +37,7 @@ namespace MapControl
         /// </summary>
         public virtual bool IsNormalCylindrical
         {
-            get { return true; }
+            get { return false; }
         }
 
         /// <summary>
diff --git a/MapControl/Shared/PolygonCollection.cs b/MapControl/Shared/PolygonCollection.cs
index aefd1ab2..da7062f9 100644
--- a/MapControl/Shared/PolygonCollection.cs
+++ b/MapControl/Shared/PolygonCollection.cs
@@ -26,9 +26,7 @@ namespace MapControl
 
         protected override void InsertItem(int index, IEnumerable<Location> polygon)
         {
-            var observablePolygon = polygon as INotifyCollectionChanged;
-
-            if (observablePolygon != null)
+            if (polygon is INotifyCollectionChanged observablePolygon)
             {
                 CollectionChangedEventManager.AddListener(observablePolygon, this);
             }
@@ -38,9 +36,7 @@ namespace MapControl
 
         protected override void SetItem(int index, IEnumerable<Location> polygon)
         {
-            var observablePolygon = this[index] as INotifyCollectionChanged;
-
-            if (observablePolygon != null)
+            if (this[index] is INotifyCollectionChanged observablePolygon)
             {
                 CollectionChangedEventManager.RemoveListener(observablePolygon, this);
             }
@@ -50,9 +46,7 @@ namespace MapControl
 
         protected override void RemoveItem(int index)
         {
-            var observablePolygon = this[index] as INotifyCollectionChanged;
-
-            if (observablePolygon != null)
+            if (this[index] is INotifyCollectionChanged observablePolygon)
             {
                 CollectionChangedEventManager.RemoveListener(observablePolygon, this);
             }
diff --git a/MapControl/Shared/WebMercatorProjection.cs b/MapControl/Shared/WebMercatorProjection.cs
index d73355db..943ef97e 100644
--- a/MapControl/Shared/WebMercatorProjection.cs
+++ b/MapControl/Shared/WebMercatorProjection.cs
@@ -22,6 +22,11 @@ namespace MapControl
             CrsId = "EPSG:3857";
         }
 
+        public override bool IsNormalCylindrical
+        {
+            get { return true; }
+        }
+
         public override bool IsWebMercator
         {
             get { return true; }
diff --git a/MapControl/Shared/WorldMercatorProjection.cs b/MapControl/Shared/WorldMercatorProjection.cs
index 2008619f..564a3238 100644
--- a/MapControl/Shared/WorldMercatorProjection.cs
+++ b/MapControl/Shared/WorldMercatorProjection.cs
@@ -25,6 +25,11 @@ namespace MapControl
             CrsId = "EPSG:3395";
         }
 
+        public override bool IsNormalCylindrical
+        {
+            get { return true; }
+        }
+
         public override double MaxLatitude
         {
             get { return maxLatitude; }
diff --git a/MapControl/UWP/ImageFileCache.UWP.cs b/MapControl/UWP/ImageFileCache.UWP.cs
index 9aea9671..08200330 100644
--- a/MapControl/UWP/ImageFileCache.UWP.cs
+++ b/MapControl/UWP/ImageFileCache.UWP.cs
@@ -17,12 +17,7 @@ namespace MapControl.Caching
 
         public ImageFileCache(StorageFolder folder)
         {
-            if (folder == null)
-            {
-                throw new ArgumentNullException("The parameter rootFolder must not be null.");
-            }
-
-            this.folder = folder;
+            this.folder = folder ?? throw new ArgumentNullException("The parameter rootFolder must not be null.");
 
             Debug.WriteLine("Created ImageFileCache in " + folder.Path);
         }
diff --git a/MapControl/UWP/MapPanel.UWP.cs b/MapControl/UWP/MapPanel.UWP.cs
index 6a840151..b140b80d 100644
--- a/MapControl/UWP/MapPanel.UWP.cs
+++ b/MapControl/UWP/MapPanel.UWP.cs
@@ -53,12 +53,9 @@ namespace MapControl
 
         private static MapBase FindParentMap(FrameworkElement element)
         {
-            var parent = VisualTreeHelper.GetParent(element) as FrameworkElement;
-
-            return parent == null ? null
-                : ((parent as MapBase)
-                ?? (MapBase)element.GetValue(ParentMapProperty)
-                ?? FindParentMap(parent));
+            return VisualTreeHelper.GetParent(element) is FrameworkElement parent
+                ? ((parent as MapBase) ?? (MapBase)element.GetValue(ParentMapProperty) ?? FindParentMap(parent))
+                : null;
         }
 
         private static void SetViewPosition(FrameworkElement element, Point? viewPosition)
diff --git a/MapControl/UWP/MapPath.UWP.cs b/MapControl/UWP/MapPath.UWP.cs
index 294da581..1bc3befb 100644
--- a/MapControl/UWP/MapPath.UWP.cs
+++ b/MapControl/UWP/MapPath.UWP.cs
@@ -21,16 +21,14 @@ namespace MapControl
 
         protected void DataCollectionPropertyChanged(DependencyPropertyChangedEventArgs e)
         {
-            INotifyCollectionChanged collection;
-
-            if ((collection = e.OldValue as INotifyCollectionChanged) != null)
+            if (e.OldValue is INotifyCollectionChanged oldCollection)
             {
-                collection.CollectionChanged -= DataCollectionChanged;
+                oldCollection.CollectionChanged -= DataCollectionChanged;
             }
 
-            if ((collection = e.NewValue as INotifyCollectionChanged) != null)
+            if (e.NewValue is INotifyCollectionChanged newCollection)
             {
-                collection.CollectionChanged += DataCollectionChanged;
+                newCollection.CollectionChanged += DataCollectionChanged;
             }
 
             UpdateData();
diff --git a/MapControl/UWP/Tile.UWP.cs b/MapControl/UWP/Tile.UWP.cs
index 7a70a90f..30740773 100644
--- a/MapControl/UWP/Tile.UWP.cs
+++ b/MapControl/UWP/Tile.UWP.cs
@@ -18,9 +18,7 @@ namespace MapControl
 
             if (fadeIn && FadeDuration > TimeSpan.Zero)
             {
-                var bitmap = image as BitmapImage;
-
-                if (bitmap?.UriSource != null)
+                if (image is BitmapImage bitmap && bitmap.UriSource != null)
                 {
                     bitmap.ImageOpened += BitmapImageOpened;
                     bitmap.ImageFailed += BitmapImageFailed;
diff --git a/MapControl/WPF/ImageFileCache.WPF.cs b/MapControl/WPF/ImageFileCache.WPF.cs
index 88e1f61e..20b2bdaf 100644
--- a/MapControl/WPF/ImageFileCache.WPF.cs
+++ b/MapControl/WPF/ImageFileCache.WPF.cs
@@ -160,9 +160,8 @@ namespace MapControl.Caching
                 throw new ArgumentNullException("The parameter key must not be null.");
             }
 
-            var imageCacheItem = value as ImageCacheItem;
 
-            if (imageCacheItem == null)
+            if (!(value is ImageCacheItem imageCacheItem))
             {
                 throw new ArgumentException("The parameter value must be a MapControl.Caching.ImageCacheItem instance.");
             }
diff --git a/MapControl/WPF/MapPath.WPF.cs b/MapControl/WPF/MapPath.WPF.cs
index 3feeff47..c68ec19c 100644
--- a/MapControl/WPF/MapPath.WPF.cs
+++ b/MapControl/WPF/MapPath.WPF.cs
@@ -35,16 +35,14 @@ namespace MapControl
 
         protected void DataCollectionPropertyChanged(DependencyPropertyChangedEventArgs e)
         {
-            INotifyCollectionChanged collection;
-
-            if ((collection = e.OldValue as INotifyCollectionChanged) != null)
+            if (e.OldValue is INotifyCollectionChanged oldCollection)
             {
-                CollectionChangedEventManager.RemoveListener(collection, this);
+                CollectionChangedEventManager.RemoveListener(oldCollection, this);
             }
 
-            if ((collection = e.NewValue as INotifyCollectionChanged) != null)
+            if (e.NewValue is INotifyCollectionChanged newCollection)
             {
-                CollectionChangedEventManager.AddListener(collection, this);
+                CollectionChangedEventManager.AddListener(newCollection, this);
             }
 
             UpdateData();
diff --git a/MapControl/WPF/Tile.WPF.cs b/MapControl/WPF/Tile.WPF.cs
index a0443f75..c35f88f0 100644
--- a/MapControl/WPF/Tile.WPF.cs
+++ b/MapControl/WPF/Tile.WPF.cs
@@ -17,9 +17,7 @@ namespace MapControl
 
             if (fadeIn && FadeDuration > TimeSpan.Zero)
             {
-                var bitmap = image as BitmapSource;
-
-                if (bitmap != null && !bitmap.IsFrozen && bitmap.IsDownloading)
+                if (image is BitmapSource bitmap && !bitmap.IsFrozen && bitmap.IsDownloading)
                 {
                     bitmap.DownloadCompleted += BitmapDownloadCompleted;
                     bitmap.DownloadFailed += BitmapDownloadFailed;
diff --git a/MapImages/Shared/WorldFileImage.cs b/MapImages/Shared/WorldFileImage.cs
index a7f28ccf..f24e00de 100644
--- a/MapImages/Shared/WorldFileImage.cs
+++ b/MapImages/Shared/WorldFileImage.cs
@@ -115,12 +115,11 @@ namespace MapControl.Images
                 .Take(6)
                 .Select((line, i) =>
                 {
-                    double p;
-                    if (!double.TryParse(line, NumberStyles.Float, CultureInfo.InvariantCulture, out p))
+                    if (!double.TryParse(line, NumberStyles.Float, CultureInfo.InvariantCulture, out double parameter))
                     {
                         throw new ArgumentException("Failed parsing line " + (i + 1) + " in world file \"" + path + "\".");
                     }
-                    return p;
+                    return parameter;
                 })
                 .ToList();
 
diff --git a/MapProjections/Shared/GeoApiProjection.cs b/MapProjections/Shared/GeoApiProjection.cs
index 3ab74db5..d51c00ed 100644
--- a/MapProjections/Shared/GeoApiProjection.cs
+++ b/MapProjections/Shared/GeoApiProjection.cs
@@ -38,12 +38,7 @@ namespace MapControl.Projections
             get { return coordinateSystem; }
             set
             {
-                if (value == null)
-                {
-                    throw new ArgumentNullException("The property value must not be null.");
-                }
-
-                coordinateSystem = value;
+                coordinateSystem = value ?? throw new ArgumentNullException("The property value must not be null.");
 
                 var transformFactory = new CoordinateTransformationFactory();
 
diff --git a/MapProjections/Shared/UtmProjection.cs b/MapProjections/Shared/UtmProjection.cs
index 66188b36..d5f28107 100644
--- a/MapProjections/Shared/UtmProjection.cs
+++ b/MapProjections/Shared/UtmProjection.cs
@@ -24,10 +24,9 @@ namespace MapControl.Projections
                     }
 
                     var hemisphere = value[value.Length - 1];
-                    int zoneNumber;
 
                     if ((hemisphere != 'N' && hemisphere != 'S') ||
-                        !int.TryParse(value.Substring(0, value.Length - 1), out zoneNumber))
+                        !int.TryParse(value.Substring(0, value.Length - 1), out int zoneNumber))
                     {
                         throw new ArgumentException("Invalid UTM zone.");
                     }
diff --git a/SQLiteCache/WPF/SQLiteCache.WPF.cs b/SQLiteCache/WPF/SQLiteCache.WPF.cs
index 272fb0b6..fe3f011b 100644
--- a/SQLiteCache/WPF/SQLiteCache.WPF.cs
+++ b/SQLiteCache/WPF/SQLiteCache.WPF.cs
@@ -169,9 +169,7 @@ namespace MapControl.Caching
                 throw new ArgumentNullException("The parameter key must not be null.");
             }
 
-            var imageCacheItem = value as ImageCacheItem;
-
-            if (imageCacheItem == null)
+            if (!(value is ImageCacheItem imageCacheItem))
             {
                 throw new ArgumentException("The parameter value must be a MapControl.Caching.ImageCacheItem instance.");
             }