fix unexpected hovor without mouse moving (#2368)

fix #975 
close #2043

Wox/ResultListBox.xaml

@@ -16,7 +16,8 @@
          KeyboardNavigation.DirectionalNavigation="Cycle" SelectionMode="Single"
          VirtualizingStackPanel.IsVirtualizing="True" VirtualizingStackPanel.VirtualizationMode="Standard"
          SelectionChanged="OnSelectionChanged"
-         IsSynchronizedWithCurrentItem="True">
+         IsSynchronizedWithCurrentItem="True"
+         PreviewMouseDown="ListBox_PreviewMouseDown">
     <!--IsSynchronizedWithCurrentItem: http://stackoverflow.com/a/7833798/2833083-->
     <ListBox.ItemTemplate>
         <DataTemplate>
@@ -65,6 +66,7 @@
     <ListBox.ItemContainerStyle>
         <Style TargetType="{x:Type ListBoxItem}">
             <EventSetter Event="MouseEnter" Handler="OnMouseEnter" />
+            <EventSetter Event="MouseMove" Handler="OnMouseMove" />
             <Setter Property="Height" Value="50" />
             <Setter Property="Margin" Value="0" />
             <Setter Property="Padding" Value="0" />

Wox/ResultListBox.xaml.cs

@@ -1,4 +1,5 @@
 using System.Runtime.Remoting.Contexts;
+using System.Windows;
 using System.Windows.Controls;
 using System.Windows.Input;
 
@@ -7,6 +8,8 @@ namespace Wox
     [Synchronization]
     public partial class ResultListBox
     {
+        private Point _lastpos;
+        private ListBoxItem curItem = null;
         public ResultListBox()
         {
             InitializeComponent();
@@ -22,7 +25,26 @@ namespace Wox
 
         private void OnMouseEnter(object sender, MouseEventArgs e)
         {
-            ((ListBoxItem) sender).IsSelected = true;
+            curItem = (ListBoxItem)sender;
+            var p = e.GetPosition((IInputElement)sender);
+            _lastpos = p;
+        }
+
+        private void OnMouseMove(object sender, MouseEventArgs e)
+        {
+            var p = e.GetPosition((IInputElement)sender);
+            if (_lastpos != p)
+            {
+                ((ListBoxItem) sender).IsSelected = true;
+            }
+        }
+
+        private void ListBox_PreviewMouseDown(object sender, MouseButtonEventArgs e)
+        {
+            if (curItem != null)
+            {
+                curItem.IsSelected = true;
+            }
         }
     }
 }