diff --git a/Wox/MainWindow.xaml b/Wox/MainWindow.xaml
index 7dfe8cd1e9..cc50e76dce 100644
--- a/Wox/MainWindow.xaml
+++ b/Wox/MainWindow.xaml
@@ -56,7 +56,7 @@
     <Border Style="{DynamicResource WindowBorderStyle}" MouseDown="OnMouseDown" >
         <StackPanel Orientation="Vertical">
             <TextBox Style="{DynamicResource QueryBoxStyle}"
-                     Text="{Binding QueryText, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"
+                     Text="{Binding QueryText, Mode=TwoWay, Delay=100, UpdateSourceTrigger=PropertyChanged}"
                      PreviewDragOver="OnPreviewDragOver"
                      TextChanged="OnTextChanged"
                      AllowDrop="True"
diff --git a/Wox/ViewModel/MainViewModel.cs b/Wox/ViewModel/MainViewModel.cs
index 78ccc54d9e..bf8530df71 100644
--- a/Wox/ViewModel/MainViewModel.cs
+++ b/Wox/ViewModel/MainViewModel.cs
@@ -13,7 +13,6 @@ using Wox.Core.Resource;
 using Wox.Helper;
 using Wox.Infrastructure;
 using Wox.Infrastructure.Hotkey;
-using Wox.Infrastructure.Image;
 using Wox.Infrastructure.Storage;
 using Wox.Infrastructure.UserSettings;
 using Wox.Plugin;
@@ -25,7 +24,7 @@ namespace Wox.ViewModel
     {
         #region Private Fields
 
-        private bool _queryHasReturn;
+        private bool _isQueryRunning;
         private Query _lastQuery;
         private string _queryTextBeforeLeaveResults;
 
@@ -41,7 +40,7 @@ namespace Wox.ViewModel
         private CancellationToken _updateToken;
         private bool _saved;
 
-        private Internationalization _translator = InternationalizationManager.Instance;
+        private readonly Internationalization _translator = InternationalizationManager.Instance;
 
         #endregion
 
@@ -312,7 +311,7 @@ namespace Wox.ViewModel
                 {
                     var filtered = results.Where
                     (
-                        r => StringMatcher.FuzzySearch(query, r.Title).IsSearchPrecisionScoreMet() 
+                        r => StringMatcher.FuzzySearch(query, r.Title).IsSearchPrecisionScoreMet()
                             || StringMatcher.FuzzySearch(query, r.SubTitle).IsSearchPrecisionScoreMet()
                     ).ToList();
                     ContextMenu.AddResults(filtered, id);
@@ -371,49 +370,33 @@ namespace Wox.ViewModel
             if (!string.IsNullOrEmpty(QueryText))
             {
                 _updateSource?.Cancel();
-                _updateSource = new CancellationTokenSource();
-                var updateToken = _updateSource.Token;
+                var currentUpdateSource = new CancellationTokenSource();
+                _updateSource = currentUpdateSource;
+                var currentCancellationToken = _updateSource.Token;
+                _updateToken = currentCancellationToken;
 
                 ProgressBarVisibility = Visibility.Hidden;
-                _queryHasReturn = false;
+                _isQueryRunning = true;
                 var query = PluginManager.QueryInit(QueryText.Trim());
                 if (query != null)
                 {
                     // handle the exclusiveness of plugin using action keyword
-                    string lastKeyword = _lastQuery.ActionKeyword;
-                    string keyword = query.ActionKeyword;
-                    if (string.IsNullOrEmpty(lastKeyword))
-                    {
-                        if (!string.IsNullOrEmpty(keyword))
-                        {
-                            Results.RemoveResultsExcept(PluginManager.NonGlobalPlugins[keyword].Metadata);
-                        }
-                    }
-                    else
-                    {
-                        if (string.IsNullOrEmpty(keyword))
-                        {
-                            Results.RemoveResultsFor(PluginManager.NonGlobalPlugins[lastKeyword].Metadata);
-                        }
-                        else if (lastKeyword != keyword)
-                        {
-                            Results.RemoveResultsExcept(PluginManager.NonGlobalPlugins[keyword].Metadata);
-                        }
-                    }
+                    RemoveOldQueryResults(query);
 
                     _lastQuery = query;
-                    Task.Delay(200, updateToken).ContinueWith(_ =>
-                    {
-                        if (query.RawQuery == _lastQuery.RawQuery && !_queryHasReturn)
+                    Task.Delay(200, currentCancellationToken).ContinueWith(_ =>
+                    { // start the progress bar if query takes more than 200 ms and this is the current running query and it didn't finish yet
+                        if (currentUpdateSource == _updateSource && _isQueryRunning)
                         {
                             ProgressBarVisibility = Visibility.Visible;
                         }
-                    }, updateToken);
+                    }, currentCancellationToken);
 
                     var plugins = PluginManager.ValidPluginsForQuery(query);
                     Task.Run(() =>
                     {
-                        var parallelOptions = new ParallelOptions {CancellationToken = updateToken}; // so looping will stop once it was cancelled
+                        // so looping will stop once it was cancelled
+                        var parallelOptions = new ParallelOptions { CancellationToken = currentCancellationToken };
                         Parallel.ForEach(plugins, parallelOptions, plugin =>
                         {
                             var config = _settings.PluginSettings.Plugins[plugin.Metadata.ID];
@@ -422,13 +405,16 @@ namespace Wox.ViewModel
                                 var results = PluginManager.QueryForPlugin(plugin, query);
                                 UpdateResultView(results, plugin.Metadata, query);
                             }
-                        });// TODO add cancel code.
+                        });
 
                         // this should happen once after all queries are done so progress bar should continue
                         // until the end of all querying
-                        _queryHasReturn = true;
-                        ProgressBarVisibility = Visibility.Hidden;
-                    }, updateToken);
+                        _isQueryRunning = false;
+                        if (currentUpdateSource == _updateSource)
+                        { // update to hidden if this is still the current query
+                            ProgressBarVisibility = Visibility.Hidden;
+                        }
+                    }, currentCancellationToken);
                 }
             }
             else
@@ -438,6 +424,30 @@ namespace Wox.ViewModel
             }
         }
 
+        private void RemoveOldQueryResults(Query query)
+        {
+            string lastKeyword = _lastQuery.ActionKeyword;
+            string keyword = query.ActionKeyword;
+            if (string.IsNullOrEmpty(lastKeyword))
+            {
+                if (!string.IsNullOrEmpty(keyword))
+                {
+                    Results.RemoveResultsExcept(PluginManager.NonGlobalPlugins[keyword].Metadata);
+                }
+            }
+            else
+            {
+                if (string.IsNullOrEmpty(keyword))
+                {
+                    Results.RemoveResultsFor(PluginManager.NonGlobalPlugins[lastKeyword].Metadata);
+                }
+                else if (lastKeyword != keyword)
+                {
+                    Results.RemoveResultsExcept(PluginManager.NonGlobalPlugins[keyword].Metadata);
+                }
+            }
+        }
+
 
         private Result ContextMenuTopMost(Result result)
         {
@@ -661,4 +671,4 @@ namespace Wox.ViewModel
 
         #endregion
     }
-}
+}
\ No newline at end of file
diff --git a/Wox/ViewModel/ResultsViewModel.cs b/Wox/ViewModel/ResultsViewModel.cs
index e36ddc94d3..76a7ee75ba 100644
--- a/Wox/ViewModel/ResultsViewModel.cs
+++ b/Wox/ViewModel/ResultsViewModel.cs
@@ -156,14 +156,14 @@ namespace Wox.ViewModel
         private List<ResultViewModel> NewResults(List<Result> newRawResults, string resultId)
         {
             var results = Results.ToList();
-            var newResults = newRawResults.Select(r => new ResultViewModel(r)).ToList();            
+            var newResults = newRawResults.Select(r => new ResultViewModel(r)).ToList();
             var oldResults = results.Where(r => r.Result.PluginID == resultId).ToList();
 
             // Find the same results in A (old results) and B (new newResults)          
             var sameResults = oldResults
                                 .Where(t1 => newResults.Any(x => x.Result.Equals(t1.Result)))
                                 .ToList();
-            
+
             // remove result of relative complement of B in A
             foreach (var result in oldResults.Except(sameResults))
             {
@@ -248,6 +248,10 @@ namespace Wox.ViewModel
                 }
             }
 
+            /// <summary>
+            /// Update the results collection with new results, try to keep identical results
+            /// </summary>
+            /// <param name="newItems"></param>
             public void Update(List<ResultViewModel> newItems)
             {
                 int newCount = newItems.Count;
@@ -259,7 +263,7 @@ namespace Wox.ViewModel
                     ResultViewModel oldResult = this[i];
                     ResultViewModel newResult = newItems[i];
                     if (!oldResult.Equals(newResult))
-                    {
+                    { // result is not the same update it in the current index
                         this[i] = newResult;
                     }
                     else if (oldResult.Result.Score != newResult.Result.Score)
@@ -286,4 +290,4 @@ namespace Wox.ViewModel
             }
         }
     }
-}
+}
\ No newline at end of file