1.infotext滑块永远在最下方

2.textblock改为textbox，获得textchanged事件
3.给textbox添加isReadOnly属性
4.下拉框每次选择后去除选择项，防止无法选择重复选项，导致无法触发SelectedChanged

SocketExample/TCPWindowV2.xaml

@@ -97,9 +97,18 @@
                                 </StackPanel>
 
                                 <StackPanel Orientation="Horizontal" Width="370" Margin="0,5,0,5" Height="100">
-                                        <Border Height="Auto" Width="200" BorderBrush="Black" BorderThickness="0.5" Margin="5,5,10,0" >
-                                            <ScrollViewer VerticalScrollBarVisibility="Auto">
-                                                <TextBlock x:Name="InfoTextBlock_Client" TextWrapping="Wrap" Text="{Binding Infotext}" Height="Auto" Width="Auto" Margin="5,5,5,5"></TextBlock>
+                                        <Border Height="Auto" Width="200" BorderBrush="Black" BorderThickness="1" Margin="5,5,10,0" >
+                                            <ScrollViewer x:Name="TextScrollViewer" VerticalScrollBarVisibility="Auto" CanContentScroll="True">
+                                                <TextBox x:Name="InfoTextBlock_Client" TextWrapping="Wrap" BorderThickness="0" IsReadOnly="True" Text="{Binding Infotext}"  Height="Auto" Width="Auto">
+                                                        <i:Interaction.Triggers>
+                                                            <i:EventTrigger EventName="TextChanged">
+                                                                <i:InvokeCommandAction 
+                                                                Command="{Binding TextChangedCommand}"
+                                                                CommandParameter="{Binding ElementName=TextScrollViewer}"
+                                                                />
+                                                            </i:EventTrigger>
+                                                        </i:Interaction.Triggers>
+                                                </TextBox>
                                              </ScrollViewer>
                                         </Border>
 

SocketExample/TCPWindowV2.xaml.cs

@@ -44,6 +44,7 @@ namespace SocketExample
             int port;
             TcpClient client;
             public string option;//命令选项
+            public ICommand TextChangedCommand { get; }
             public ICommand SelectionChangedCommand { get; }
 
             public ICommand GPOSelectionChangedCommand { get; }
@@ -168,6 +169,7 @@ namespace SocketExample
                 getpowercomn = new LinkCommand(Button_GetPower);
                 SelectionChangedCommand = new RelayCommand<ComboBox>(ComboBox_SelectChanged);
                 GPOSelectionChangedCommand = new RelayCommand<ComboBox>(GPOComboBox_SelectChanged);
+                TextChangedCommand = new RelayCommand<ScrollViewer>(TextBlock_SelectChanged);
 
                 try
                 {
@@ -475,7 +477,7 @@ namespace SocketExample
 
 
                 Thread GPIOthread = new Thread(new ThreadStart(delegate () { byte[] data = strToToHexByte("AA 55 00 81 81 0D"); client.Send(data); Thread.Sleep(3000); }));
-                //GPIOthread.Start();
+                GPIOthread.Start();
                 return EasyTask.CompletedTask;
             }
             #endregion
@@ -651,6 +653,11 @@ namespace SocketExample
                 Infotext = string.Empty;//清空信息框
             }
 
+            void TextBlock_SelectChanged(ScrollViewer scrollViewer)
+            {
+                scrollViewer.ScrollToVerticalOffset(scrollViewer.ExtentHeight);
+            }
+
             void ComboBox_SelectChanged(ComboBox sender)
             {
                 string comboxname = sender.Name;
@@ -719,7 +726,7 @@ namespace SocketExample
                     }
                     if (sender.SelectedItem?.ToString() == "高")
                         Order += "01 ";
-                    else
+                    else if(sender.SelectedItem?.ToString() == "低")
                         Order += "00 ";
                     Order += "00 00 ";
                     Order += Convert.ToString(GetXor(strToToHexByte(Order), 2), 16) + " 0D";
@@ -728,6 +735,7 @@ namespace SocketExample
                     client.Send(data);
                     data = strToToHexByte("AA 55 00 81 81 0D");//获取GPIO状态
                     client.Send(data);
+                    sender.SelectedIndex = -1;
                     //SaveCommand();
                 }
                 catch (Exception ex)