diff --git a/BililiveRecorder.WPF/Pages/ToolboxDanmakuMergerPage.xaml b/BililiveRecorder.WPF/Pages/ToolboxDanmakuMergerPage.xaml
index 27fa37c..0f4b667 100644
--- a/BililiveRecorder.WPF/Pages/ToolboxDanmakuMergerPage.xaml
+++ b/BililiveRecorder.WPF/Pages/ToolboxDanmakuMergerPage.xaml
@@ -6,16 +6,26 @@
     xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
     xmlns:ui="http://schemas.modernwpf.com/2019"
     xmlns:l="https://github.com/XAMLMarkupExtensions/WPFLocalizationExtension"
+    xmlns:scm="clr-namespace:System.ComponentModel;assembly=WindowsBase"
     l:LocalizeDictionary.DesignCulture=""
     l:ResxLocalizationProvider.DefaultAssembly="BililiveRecorder.WPF"
     l:ResxLocalizationProvider.DefaultDictionary="Strings"
     mc:Ignorable="d" DataContext="{x:Null}"
     d:DesignHeight="450" d:DesignWidth="800"
     Title="ToolboxDanmakuMergerPage">
+    <ui:Page.Resources>
+        <ResourceDictionary>
+            <ResourceDictionary.MergedDictionaries>
+                <ResourceDictionary Source="pack://application:,,,/ModernWpf;component/DensityStyles/Compact.xaml" />
+            </ResourceDictionary.MergedDictionaries>
+            <CollectionViewSource x:Key="cvs">
+                <CollectionViewSource.SortDescriptions>
+                    <scm:SortDescription PropertyName="Path" Direction="Ascending"/>
+                </CollectionViewSource.SortDescriptions>
+            </CollectionViewSource>
+        </ResourceDictionary>
+    </ui:Page.Resources>
     <Grid>
-        <Grid.Resources>
-            <ResourceDictionary Source="pack://application:,,,/ModernWpf;component/DensityStyles/Compact.xaml" />
-        </Grid.Resources>
         <Grid.RowDefinitions>
             <RowDefinition Height="Auto"/>
             <RowDefinition Height="Auto"/>
@@ -28,7 +38,7 @@
             <Button Margin="0,0,5,0" Content="{l:Loc Toolbox_Merge_Button_AddFile}" Click="AddFile_Click"/>
             <Button Content="{l:Loc Toolbox_Merge_Button_Merge}" Click="Merge_Click"/>
         </StackPanel>
-        <ListView Grid.Row="3" Margin="5" x:Name="listView" AllowDrop="True" Drop="DragDrop">
+        <ListView Grid.Row="3" Margin="5" x:Name="listView" ItemsSource="{Binding Source={StaticResource cvs}}" AllowDrop="True" Drop="DragDrop">
             <ListView.View>
                 <GridView AllowsColumnReorder="False">
                     <GridViewColumn>
@@ -41,7 +51,8 @@
                     </GridViewColumn>
                     <GridViewColumn Header="偏移量（秒）" Width="120">
                         <GridViewColumn.CellTemplate>
-                            <DataTemplate><!--
+                            <DataTemplate>
+                                <!--
                                 <ui:NumberBox Minimum="0" SmallChange="1" LargeChange="10" Text="{Binding Offset,UpdateSourceTrigger=PropertyChanged}"
                                           SpinButtonPlacementMode="Inline" ValidationMode="InvalidInputOverwritten"/>
                                 -->
diff --git a/BililiveRecorder.WPF/Pages/ToolboxDanmakuMergerPage.xaml.cs b/BililiveRecorder.WPF/Pages/ToolboxDanmakuMergerPage.xaml.cs
index 42797a7..ccaac5e 100644
--- a/BililiveRecorder.WPF/Pages/ToolboxDanmakuMergerPage.xaml.cs
+++ b/BililiveRecorder.WPF/Pages/ToolboxDanmakuMergerPage.xaml.cs
@@ -6,6 +6,7 @@ using System.Threading;
 using System.Threading.Tasks;
 using System.Windows;
 using System.Windows.Controls;
+using System.Windows.Data;
 using System.Windows.Threading;
 using BililiveRecorder.ToolBox;
 using BililiveRecorder.ToolBox.Tool.DanmakuMerger;
@@ -32,7 +33,9 @@ namespace BililiveRecorder.WPF.Pages
         public ToolboxDanmakuMergerPage()
         {
             this.InitializeComponent();
-            this.listView.ItemsSource = this.Files;
+
+            var cvs = (CollectionViewSource)this.FindResource("cvs");
+            cvs.Source = this.Files;
         }
 
         private void RemoveFile_Click(object sender, RoutedEventArgs e)
@@ -86,7 +89,8 @@ namespace BililiveRecorder.WPF.Pages
 
         private async Task AddFilesAsync(string[] paths)
         {
-            var req = new DanmakuStartTimeRequest { Inputs = paths };
+            // filter duplicate file paths
+            var req = new DanmakuStartTimeRequest { Inputs = paths.Where(x => !this.Files.Any(f => f.Path == x)).ToArray() };
             var handler = new DanmakuStartTimeHandler();
             var resp = await handler.Handle(req, default, default).ConfigureAwait(true);
 
@@ -111,9 +115,6 @@ namespace BililiveRecorder.WPF.Pages
             {
                 item.Offset = (int)(item.StartTime - minTime).TotalSeconds;
             }
-
-            this.listView.DataContext = null;
-            this.listView.DataContext = this.Files;
         }
 
 #pragma warning disable VSTHRD100 // Avoid async void methods
@@ -188,7 +189,7 @@ namespace BililiveRecorder.WPF.Pages
 
                 logger.Debug("弹幕合并结果 {@Response}", resp);
 
-                if (resp.Status != ResponseStatus.Cancelled && resp.Status != ResponseStatus.OK)
+                if (resp.Status is not ResponseStatus.Cancelled and not ResponseStatus.OK)
                 {
                     logger.Warning(resp.Exception, "弹幕合并时发生错误 (@Status)", resp.Status);
                     await Task.Run(() => ShowErrorMessageBox(resp)).ConfigureAwait(true);