Update KeyboardHandler to ignore left, right, up, down as they were being cancelled

Some resharper inspired cleanup as well

Author: amaitland

CefSharp.WinForms.Example/Handlers/KeyboardHandler.cs

@@ -16,21 +16,25 @@ public bool OnPreKeyEvent(IWebBrowser browserControl, IBrowser browser, KeyType
             const int WM_CHAR = 0x102;
             const int WM_SYSCHAR = 0x106;
             const int VK_TAB = 0x9;
-
-            bool result = false;
+            const int VK_LEFT = 0x25;
+            const int VK_UP = 0x26;
+            const int VK_RIGHT = 0x27;
+            const int VK_DOWN = 0x28;
 
             isKeyboardShortcut = false;
 
             // Don't deal with TABs by default:
             // TODO: Are there any additional ones we need to be careful of?
             // i.e. Escape, Return, etc...?
-            if (windowsKeyCode == VK_TAB)
+            if (windowsKeyCode == VK_TAB || windowsKeyCode == VK_LEFT || windowsKeyCode == VK_UP || windowsKeyCode == VK_DOWN || windowsKeyCode == VK_RIGHT)
             {
-                return result;
+                return false;
             }
 
-            Control control = browserControl as Control;
-            int msgType = 0;
+            var result = false;
+
+            var control = browserControl as Control;
+            var msgType = 0;
             switch (type)
             {
             case KeyType.RawKeyDown:
@@ -69,17 +73,23 @@ public bool OnPreKeyEvent(IWebBrowser browserControl, IBrowser browser, KeyType
             }
             // We have to adapt from CEF's UI thread message loop to our fronting WinForm control here.
             // So, we have to make some calls that Application.Run usually ends up handling for us:
-            PreProcessControlState state = PreProcessControlState.MessageNotNeeded;
+            var state = PreProcessControlState.MessageNotNeeded;
             // We can't use BeginInvoke here, because we need the results for the return value
             // and isKeyboardShortcut. In theory this shouldn't deadlock, because
             // atm this is the only synchronous operation between the two threads.
             control.Invoke(new Action(() =>
             {
-                Message msg = new Message() { HWnd = control.Handle, Msg = msgType, WParam = new IntPtr(windowsKeyCode), LParam = new IntPtr(nativeKeyCode) };
+                var msg = new Message
+                {
+                    HWnd = control.Handle,
+                    Msg = msgType,
+                    WParam = new IntPtr(windowsKeyCode),
+                    LParam = new IntPtr(nativeKeyCode)
+                };
 
                 // First comes Application.AddMessageFilter related processing:
                 // 99.9% of the time in WinForms this doesn't do anything interesting.
-                bool processed = Application.FilterMessage(ref msg);
+                var processed = Application.FilterMessage(ref msg);
                 if (processed)
                 {
                     state = PreProcessControlState.MessageProcessed;
@@ -92,6 +102,7 @@ public bool OnPreKeyEvent(IWebBrowser browserControl, IBrowser browser, KeyType
                     state = control.PreProcessControlMessage(ref msg);
                 }
             }));
+
             if (state == PreProcessControlState.MessageNeeded)
             {
                 // TODO: Determine how to track MessageNeeded for OnKeyEvent.
@@ -102,16 +113,18 @@ public bool OnPreKeyEvent(IWebBrowser browserControl, IBrowser browser, KeyType
                 // Most of the interesting cases get processed by PreProcessControlMessage.
                 result = true;
             }
-            Debug.WriteLine(String.Format("OnPreKeyEvent: KeyType: {0} 0x{1:X} Modifiers: {2}", type, windowsKeyCode, modifiers));
-            Debug.WriteLine(String.Format("OnPreKeyEvent PreProcessControlState: {0}", state));
+
+            Debug.WriteLine("OnPreKeyEvent: KeyType: {0} 0x{1:X} Modifiers: {2}", type, windowsKeyCode, modifiers);
+            Debug.WriteLine("OnPreKeyEvent PreProcessControlState: {0}", state);
+
             return result;
         }
 
         /// <inheritdoc/>>
         public bool OnKeyEvent(IWebBrowser browserControl, IBrowser browser, KeyType type, int windowsKeyCode, int nativeKeyCode, CefEventFlags modifiers, bool isSystemKey)
         {
-            bool result = false;
-            Debug.WriteLine(String.Format("OnKeyEvent: KeyType: {0} 0x{1:X} Modifiers: {2}", type, windowsKeyCode, modifiers));
+            var result = false;
+            Debug.WriteLine("OnKeyEvent: KeyType: {0} 0x{1:X} Modifiers: {2}", type, windowsKeyCode, modifiers);
             // TODO: Handle MessageNeeded cases here somehow.
             return result;
         }