Merge pull request #4313 from Flow-Launcher/InitProgressbarAnimation_Null

Move progress bar animation init to Loaded event to fix possible null exception of ProgressBar

Flow.Launcher/MainWindow.xaml

@@ -342,6 +342,7 @@
                     Margin="12 0 12 0"
                     HorizontalAlignment="Center"
                     VerticalAlignment="Bottom"
+                    Loaded="ProgressBar_Loaded"
                     StrokeThickness="2"
                     Visibility="{Binding ProgressBarVisibility, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"
                     X1="-100"

Flow.Launcher/MainWindow.xaml.cs

@@ -199,9 +199,6 @@ namespace Flow.Launcher
                 ThemeManager.Current.ApplicationTheme = ApplicationTheme.Dark;
             }
 
-            // Initialize position
-            InitProgressbarAnimation();
-
             // Force update position
             UpdatePosition();
 
@@ -354,6 +351,11 @@ namespace Flow.Launcher
             }
         }
 
+        private void ProgressBar_Loaded(object sender, RoutedEventArgs e)
+        {
+            InitProgressbarAnimation();
+        }
+
         private async void OnClosing(object sender, CancelEventArgs e)
         {
             if (!CanClose)