diff --git a/InkCanvasForClass/MainWindow.xaml b/InkCanvasForClass/MainWindow.xaml
index e118ca4..bda1577 100644
--- a/InkCanvasForClass/MainWindow.xaml
+++ b/InkCanvasForClass/MainWindow.xaml
@@ -2739,7 +2739,7 @@
                     </Grid>
                 </Viewbox>
                 <!-- 右下角 -->
-                <Viewbox x:Name="ViewboxBlackboardRightSide" Margin="3,0,0,0" Height="55" HorizontalAlignment="Right"
+                <Viewbox x:Name="ViewboxBlackboardRightSide" Margin="0,0,3,0" Height="55" HorizontalAlignment="Right"
                          VerticalAlignment="Bottom">
                     <Viewbox.LayoutTransform>
                         <ScaleTransform x:Name="ViewboxBlackboardRightSideScaleTransform" ScaleX="1" ScaleY="1" />
@@ -6663,7 +6663,7 @@
                                                          Toggled="ToggleSwitchRegistryShowBlackScreenLastSlideShow_Toggled" />
                                     </ui:SimpleStackPanel>
                                     <TextBlock
-                                        Text="# 以上功能会修改注册表，需要管理员权限运行。操作前请先备份注册表。选项仅支持最新Office 365，在其他版本上未经测试。"
+                                        Text="# 以上功能会修改注册表，需要管理员权限运行。操作前请先备份注册表。选项仅支持最新Office 365和WPS，其他版本未经测试。"
                                         TextWrapping="Wrap" Foreground="#a1a1aa" />
                                     <Line HorizontalAlignment="Center" X1="0" Y1="0" X2="400" Y2="0" Stroke="#3f3f46"
                                           StrokeThickness="1" Margin="0,4,0,4" />
diff --git a/InkCanvasForClass/MainWindow_cs/MW_PPT.cs b/InkCanvasForClass/MainWindow_cs/MW_PPT.cs
index 2dddbdd..ad93494 100644
--- a/InkCanvasForClass/MainWindow_cs/MW_PPT.cs
+++ b/InkCanvasForClass/MainWindow_cs/MW_PPT.cs
@@ -243,6 +243,7 @@ namespace Ink_Canvas {
 
 
         private string pptName = null;
+        int currentShowPosition = -1;
 
         private void UpdatePPTBtnStyleSettingsStatus() {
             var sopt = Settings.PowerPointSettings.PPTSButtonsOption.ToString();
@@ -549,6 +550,17 @@ namespace Ink_Canvas {
                     File.WriteAllText(folderPath + "/Position", previousSlideID.ToString());
                 }
                 catch { }
+                Application.Current.Dispatcher.Invoke(() =>
+                {
+                    try
+                    {
+                        MemoryStream ms = new MemoryStream();
+                        inkCanvas.Strokes.Save(ms);
+                        ms.Position = 0;
+                        memoryStreams[currentShowPosition] = ms;
+                    }
+                    catch { }
+                });
 
                 for (var i = 1; i <= Pres.Slides.Count; i++)
                     if (memoryStreams[i] != null)
@@ -627,6 +639,8 @@ namespace Ink_Canvas {
                     if (memoryStreams[Wn.View.CurrentShowPosition] != null &&
                         memoryStreams[Wn.View.CurrentShowPosition].Length > 0)
                         inkCanvas.Strokes.Add(new StrokeCollection(memoryStreams[Wn.View.CurrentShowPosition]));
+
+                    currentShowPosition = Wn.View.CurrentShowPosition;
                 }
                 catch {
                     // ignored
@@ -638,6 +652,7 @@ namespace Ink_Canvas {
                 //PptNavigationTextBlock.Text = $"{Wn.View.CurrentShowPosition}/{Wn.Presentation.Slides.Count}";
             });
             previousSlideID = Wn.View.CurrentShowPosition;
+
         }
 
         private bool _isPptClickingBtnTurned = false;