WPF开发经验-实现Win10虚拟触摸键盘

一 引入

项目有个需求，需要实现纯触控操作进行键盘输入。项目部署在Win10系统上，考虑有两种方案来实现。

通过调用Win10自带的触摸键盘来实现；
通过WPF实现一个触摸键盘来实现；

---

二 调用Win10自带的触摸键盘

简单附上一个调用Win10系统的TabTip.exe的操作类。

public class TabTipHelper

{

    private const int WM_SYSCOMMAND = 274;

    private const uint SC_CLOSE = 61536;

    private const uint SC_RESTORE = 0xF120;

    private const uint SC_MAXIMIZE = 0xF030;

    private const uint SC_MINIMIZE = 0xF020;

    [DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Auto)]

    private static extern bool PostMessage(IntPtr hWnd, int Msg, int wParam, int lParam);

    [DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Auto)]

    private static extern bool PostMessage(IntPtr hWnd, int Msg, uint wParam, uint lParam);

    [DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Auto)]

    private static extern bool PostMessage(IntPtr hWnd, uint Msg, IntPtr wParam, IntPtr lParam);

    [DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Auto)]

    private static extern IntPtr FindWindow(string lpClassName, string lpWindowName);

    [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]

    private static extern int RegisterWindowMessage(string lpString);

    public static int ShowTaptip()

    {

        try

        {

            dynamic file = "C:\\Program Files\\Common Files\\microsoft shared\\ink\\TabTip.exe";

            if (!System.IO.File.Exists(file))

                return -1;

            Process.Start(file);

            return 1;

        }

        catch (Exception)

        {

            return 255;

        }

    }

    public static async Task ShowTaptipAsync()

    {

        await Task.Run(() => ShowTaptip());

    }

    public static void CloseTaptip()

    {

        var touchhWnd = new IntPtr(0);

        touchhWnd = FindWindow("IPTip_Main_Window", null);

        if (touchhWnd == IntPtr.Zero)

            return;

        PostMessage(touchhWnd, WM_SYSCOMMAND, SC_CLOSE, 0);

    }

}

---

三 通过WPF实现一个触摸键盘

下图为demo效果：

当TextBox获取焦点时，弹出键盘。当TextBox失去焦点时，隐藏键盘。

点击键盘的右上角的关闭键或Esc键隐藏键盘。

因项目不需要全键位，所有针对性地对键位进行了删减和排列。

---

---

3.1 SoftKeyboardControl控件

使用WPF的UserControl实现虚拟键盘，下附SoftKeyboardControl的后台代码。

    /// <summary>

    /// SoftKeyboardControl.xaml 的交互逻辑

    /// </summary>

    public partial class SoftKeyboardControl : UserControl

    {

        /// <summary>

        /// Windows提供的一个模拟键盘API。

        /// Keybd_event()函数能触发一个按键事件，生成一个 WM_KEYDOWN 或 WM_KEYUP 消息。

        /// </summary>

        /// <param name="bVk" >按键的虚拟键值</param>

        /// <param name= "bScan" >扫描码，一般不用设置，用0代替就行</param>

        /// <param name= "dwFlags" >选项标志：0：表示按下，2：表示松开</param>

        /// <param name= "dwExtraInfo">一般设置为0</param>

        [DllImport("User32.dll")]

        public static extern void keybd_event(byte bVK, byte bScan, int dwFlags, int dwExtraInfo);

        public SoftKeyboardControl()

        {

            InitializeComponent();

            CreateKeys();

            KeyCommand = new RoutedCommand();

            CommandBinding cmdBinding = new CommandBinding(KeyCommand, KeyCommand_Excuted, KeyCommand_CanExcute);

            CommandBindings.Add(cmdBinding);

        }

        #region 虚拟键值

        /// <summary>

        /// 键和虚拟键值的字典

        /// </summary>

        private Dictionary<string, byte> keys;

        /// <summary>

        /// 初始化虚拟键值的字典

        /// </summary>

        private void CreateKeys()

        {

            keys = new Dictionary<string, byte>()

            {

                #region 数字键盘

                { "0",0x60},

                { "1",0x61},

                { "2",0x62},

                { "3",0x63},

                { "4",0x64},

                { "5",0x65},

                { "6",0x66},

                { "7",0x67},

                { "8",0x68},

                { "9",0x69},

                { "-",0x6d},

                { ".",0x6E},

                #endregion

                #region Q字母行

                { "q", 0x51},

                { "w", 0x57},

                { "e", 0x45},

                { "r", 0x52},

                { "t", 0x54},

                { "y", 0x59},

                { "u", 0x55},

                { "i", 0x49},

                { "o", 0x4f},

                { "p", 0x50},

                { "Q", 0x51},

                { "W", 0x57},

                { "E", 0x45},

                { "R", 0x52},

                { "T", 0x54},

                { "Y", 0x59},

                { "U", 0x55},

                { "I", 0x49},

                { "O", 0x4f},

                { "P", 0x50},

                #endregion

                #region A字母行

                { "a", 0x41},

                { "s", 0x53},

                { "d", 0x44},

                { "f", 0x46},

                { "g", 0x47},

                { "h", 0x48},

                { "j", 0x4A},

                { "k", 0x4B},

                { "l", 0x4C},

                { "A", 0x41},

                { "S", 0x53},

                { "D", 0x44},

                { "F", 0x46},

                { "G", 0x47},

                { "H", 0x48},

                { "J", 0x4A},

                { "K", 0x4B},

                { "L", 0x4C},

                #endregion

                #region Z字母行

                { "z", 0x5A},

                { "x", 0x58},

                { "c", 0x43},

                { "v", 0x56},

                { "b", 0x42},

                { "n", 0x4E},

                { "m", 0x4D},

                { "Z", 0x5A},

                { "X", 0x58},

                { "C", 0x43},

                { "V", 0x56},

                { "B", 0x42},

                { "N", 0x4E},

                { "M", 0x4D},

                #endregion

                #region other

                {"BackSpace",0x08 },

                {"Tab",0x09 },

                {"Enter",0x0d },

                {"Shift",0x10 },

                {"Ctrl",0x11 },

                {"CapsLock",0x14 },

                {"Space",0x20 },

                #endregion

            };

        }

        #endregion

        #region DependencyProperty

        public static readonly DependencyProperty CapsProperty = DependencyProperty.Register(

            "Caps", typeof(bool), typeof(SoftKeyboardControl), new PropertyMetadata(default(bool)));

        public bool Caps

        {

            get { return (bool)GetValue(CapsProperty); }

            set { SetValue(CapsProperty, value); }

        }

        public static readonly DependencyProperty CtrlProperty = DependencyProperty.Register(

            "Ctrl", typeof(bool), typeof(SoftKeyboardControl), new PropertyMetadata(default(bool)));

        public bool Ctrl

        {

            get { return (bool)GetValue(CtrlProperty); }

            set { SetValue(CtrlProperty, value); }

        }

        public static readonly DependencyProperty ShiftProperty = DependencyProperty.Register(

            "Shift", typeof(bool), typeof(SoftKeyboardControl), new PropertyMetadata(default(bool)));

        public bool Shift

        {

            get { return (bool)GetValue(ShiftProperty); }

            set { SetValue(ShiftProperty, value); }

        }

        #endregion

        #region Command

        public ICommand KeyCommand { get; set; }

        private void KeyCommand_CanExcute(object sender, CanExecuteRoutedEventArgs e)

        {

            e.CanExecute = true;

        }

        private void KeyCommand_Excuted(object sender, ExecutedRoutedEventArgs e)

        {

            if (e.Parameter != null)

            {

                var code = e.Parameter.ToString();

                if (keys.ContainsKey(code))

                {

                    byte b = keys[code];

                    try

                    {

                        keybd_event(b, 0, 0, 0);

                    }

                    catch (Exception ex)

                    {

                        Console.WriteLine(ex.Message);

                    }

                }

            }

        }

        public ICommand CloseCommand { get; set; }

        #endregion

        protected override void OnPropertyChanged(DependencyPropertyChangedEventArgs e)

        {

            base.OnPropertyChanged(e);

            if (e.Property == CapsProperty)

            {

                keybd_event(0x14, 0, 0, 0);//按下

                keybd_event(0x14, 0, 2, 0); //抬起

            }

            else if (e.Property == ShiftProperty)

            {

                keybd_event(0x10, 0, 0, 0);

                keybd_event(0x10, 0, 2, 0);

            }

            else if (e.Property == CtrlProperty)

            {

                keybd_event(0x11, 0, 0, 0);

                keybd_event(0x11, 0, 2, 0);

            }

        }

    }

    /// <summary>

    /// 大小写转换

    /// </summary>

    public class UpperConverter : IValueConverter

    {

        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)

        {

            if (parameter == null)

            {

                return "";

            }

            if (value == null)

            {

                return parameter.ToString();

            }

            if ((bool)value)

            {

                return parameter.ToString().ToUpper();

            }

            else

            {

                return parameter.ToString().ToLower();

            }

        }

        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)

        {

            throw new NotImplementedException();

        }

    }

下附SoftKeyboardControl的前台代码。

注：其中按钮的样式是自己的控件库中实现的，未贴出。

<UserControl x:Class="UI.View.SoftKeyboardControl"

             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"

             xmlns:d="http://schemas.microsoft.com/expression/blend/2008"

             xmlns:local="clr-namespace:UI.View"

             mc:Ignorable="d"

             Background="#E6E6E6">

    <UserControl.Resources>

        <local:UpperConverter x:Key="UpperConverter"/>

    </UserControl.Resources>

    <StackPanel Margin="6 0 6 6">

        <StackPanel Height="40" Orientation="Horizontal" >

            <!--关闭按钮-->

        </StackPanel>

        <StackPanel Orientation="Horizontal" Margin="0 6 0 0" >

            <StackPanel>

                <WrapPanel>

                    <Button Content="Esc"  Width="85" Height="Auto" Padding="0"

                            Command="{Binding CloseCommand,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}" />

                    <Button Content="{Binding Path=Caps,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}},

                                        Converter={StaticResource UpperConverter},ConverterParameter=q}"

                            Command="{Binding KeyCommand,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"

                            CommandParameter="{Binding Path=Content,RelativeSource={RelativeSource Self}}"/>

                    <Button Content="{Binding Path=Caps,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}},

                                        Converter={StaticResource UpperConverter},ConverterParameter=w}"

                            Command="{Binding KeyCommand,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"

                            CommandParameter="{Binding Path=Content,RelativeSource={RelativeSource Self}}"/>

                    <Button Content="{Binding Path=Caps,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}},

                                        Converter={StaticResource UpperConverter},ConverterParameter=e}"

                            Command="{Binding KeyCommand,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"

                            CommandParameter="{Binding Path=Content,RelativeSource={RelativeSource Self}}"/>

                    <Button Content="{Binding Path=Caps,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}},

                                        Converter={StaticResource UpperConverter},ConverterParameter=r}"

                            Command="{Binding KeyCommand,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"

                            CommandParameter="{Binding Path=Content,RelativeSource={RelativeSource Self}}"/>

                    <Button Content="{Binding Path=Caps,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}},

                                        Converter={StaticResource UpperConverter},ConverterParameter=t}"

                            Command="{Binding KeyCommand,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"

                            CommandParameter="{Binding Path=Content,RelativeSource={RelativeSource Self}}"/>

                    <Button Content="{Binding Path=Caps,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}},

                                        Converter={StaticResource UpperConverter},ConverterParameter=y}"

                            Command="{Binding KeyCommand,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"

                            CommandParameter="{Binding Path=Content,RelativeSource={RelativeSource Self}}"/>

                    <Button Content="{Binding Path=Caps,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}},

                                        Converter={StaticResource UpperConverter},ConverterParameter=u}"

                            Command="{Binding KeyCommand,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"

                            CommandParameter="{Binding Path=Content,RelativeSource={RelativeSource Self}}"/>

                    <Button Content="{Binding Path=Caps,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}},

                                        Converter={StaticResource UpperConverter},ConverterParameter=i}"

                            Command="{Binding KeyCommand,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"

                            CommandParameter="{Binding Path=Content,RelativeSource={RelativeSource Self}}"/>

                    <Button Content="{Binding Path=Caps,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}},

                                        Converter={StaticResource UpperConverter},ConverterParameter=o}"

                            Command="{Binding KeyCommand,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"

                            CommandParameter="{Binding Path=Content,RelativeSource={RelativeSource Self}}"/>

                    <Button Content="{Binding Path=Caps,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}},

                                        Converter={StaticResource UpperConverter},ConverterParameter=p}"

                            Command="{Binding KeyCommand,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"

                            CommandParameter="{Binding Path=Content,RelativeSource={RelativeSource Self}}"/>

                </WrapPanel>

                <WrapPanel>

                    <ToggleButton Width="100" Content="Caps"

                            IsChecked="{Binding Caps,Mode=TwoWay,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"/>

                    <Button Content="{Binding Path=Caps,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}},

                                        Converter={StaticResource UpperConverter},ConverterParameter=a}"

                            Command="{Binding KeyCommand,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"

                            CommandParameter="{Binding Path=Content,RelativeSource={RelativeSource Self}}"/>

                    <Button Content="{Binding Path=Caps,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}},

                                        Converter={StaticResource UpperConverter},ConverterParameter=s}"

                            Command="{Binding KeyCommand,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"

                            CommandParameter="{Binding Path=Content,RelativeSource={RelativeSource Self}}"/>

                    <Button Content="{Binding Path=Caps,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}},

                                        Converter={StaticResource UpperConverter},ConverterParameter=d}"

                            Command="{Binding KeyCommand,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"

                            CommandParameter="{Binding Path=Content,RelativeSource={RelativeSource Self}}"/>

                    <Button Content="{Binding Path=Caps,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}},

                                        Converter={StaticResource UpperConverter},ConverterParameter=f}"

                            Command="{Binding KeyCommand,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"

                            CommandParameter="{Binding Path=Content,RelativeSource={RelativeSource Self}}"/>

                    <Button Content="{Binding Path=Caps,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}},

                                        Converter={StaticResource UpperConverter},ConverterParameter=g}"

                            Command="{Binding KeyCommand,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"

                            CommandParameter="{Binding Path=Content,RelativeSource={RelativeSource Self}}"/>

                    <Button Content="{Binding Path=Caps,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}},

                                        Converter={StaticResource UpperConverter},ConverterParameter=h}"

                            Command="{Binding KeyCommand,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"

                            CommandParameter="{Binding Path=Content,RelativeSource={RelativeSource Self}}"/>

                    <Button Content="{Binding Path=Caps,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}},

                                        Converter={StaticResource UpperConverter},ConverterParameter=j}"

                            Command="{Binding KeyCommand,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"

                            CommandParameter="{Binding Path=Content,RelativeSource={RelativeSource Self}}"/>

                    <Button Content="{Binding Path=Caps,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}},

                                        Converter={StaticResource UpperConverter},ConverterParameter=k}"

                            Command="{Binding KeyCommand,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"

                            CommandParameter="{Binding Path=Content,RelativeSource={RelativeSource Self}}"/>

                    <Button Content="{Binding Path=Caps,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}},

                                        Converter={StaticResource UpperConverter},ConverterParameter=l}"

                            Command="{Binding KeyCommand,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"

                            CommandParameter="{Binding Path=Content,RelativeSource={RelativeSource Self}}"/>

                </WrapPanel>

                <WrapPanel>

                    <ToggleButton Width="115" Padding="-18 0 0 0 " Content="Shift"

                            IsChecked="{Binding Shift,Mode=TwoWay,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"/>

                    <Button Content="{Binding Path=Caps,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}},

                                        Converter={StaticResource UpperConverter},ConverterParameter=z}"

                            Command="{Binding KeyCommand,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"

                            CommandParameter="{Binding Path=Content,RelativeSource={RelativeSource Self}}"/>

                    <Button Content="{Binding Path=Caps,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}},

                                        Converter={StaticResource UpperConverter},ConverterParameter=x}"

                            Command="{Binding KeyCommand,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"

                            CommandParameter="{Binding Path=Content,RelativeSource={RelativeSource Self}}"/>

                    <Button Content="{Binding Path=Caps,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}},

                                        Converter={StaticResource UpperConverter},ConverterParameter=c}"

                            Command="{Binding KeyCommand,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"

                            CommandParameter="{Binding Path=Content,RelativeSource={RelativeSource Self}}"/>

                    <Button Content="{Binding Path=Caps,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}},

                                        Converter={StaticResource UpperConverter},ConverterParameter=v}"

                            Command="{Binding KeyCommand,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"

                            CommandParameter="{Binding Path=Content,RelativeSource={RelativeSource Self}}"/>

                    <Button Content="{Binding Path=Caps,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}},

                                        Converter={StaticResource UpperConverter},ConverterParameter=b}"

                            Command="{Binding KeyCommand,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"

                            CommandParameter="{Binding Path=Content,RelativeSource={RelativeSource Self}}"/>

                    <Button Content="{Binding Path=Caps,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}},

                                        Converter={StaticResource UpperConverter},ConverterParameter=n}"

                            Command="{Binding KeyCommand,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"

                            CommandParameter="{Binding Path=Content,RelativeSource={RelativeSource Self}}"/>

                    <Button Content="{Binding Path=Caps,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}},

                                        Converter={StaticResource UpperConverter},ConverterParameter=m}"

                            Command="{Binding KeyCommand,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"

                            CommandParameter="{Binding Path=Content,RelativeSource={RelativeSource Self}}"/>

                    <Button Width="125" Content="Enter"

                            Command="{Binding KeyCommand,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"

                            CommandParameter="{Binding Path=Content,RelativeSource={RelativeSource Self}}"/>

                </WrapPanel>

                <WrapPanel>

                    <ToggleButton  Width="115" Padding="-28 0 0 0 " Content="Ctrl"

                            IsChecked="{Binding Ctrl,Mode=TwoWay,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"/>

                    <Button Content="Space" Width="185" Margin="50 0 0 0"

                            Command="{Binding KeyCommand,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"

                            CommandParameter="{Binding Path=Content,RelativeSource={RelativeSource Self}}"/>

                    <Button Content="BackSpace" Width="170" Margin="50 0 0 0"

                            Command="{Binding KeyCommand,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"

                            CommandParameter="{Binding Path=Content,RelativeSource={RelativeSource Self}}"/>

                </WrapPanel>

            </StackPanel>

            <Grid Width="auto" Height="auto">

                <Grid.RowDefinitions>

                    <RowDefinition/>

                    <RowDefinition/>

                    <RowDefinition/>

                    <RowDefinition/>

                </Grid.RowDefinitions>

                <Grid.ColumnDefinitions>

                    <ColumnDefinition/>

                    <ColumnDefinition/>

                    <ColumnDefinition/>

                    <ColumnDefinition/>

                </Grid.ColumnDefinitions>

                <Button Content="7"

                        Command="{Binding KeyCommand,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"

                        CommandParameter="{Binding Path=Content,RelativeSource={RelativeSource Self}}"/>

                <Button Content="8" Grid.Column="1"

                        Command="{Binding KeyCommand,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"

                        CommandParameter="{Binding Path=Content,RelativeSource={RelativeSource Self}}"/>

                <Button Content="9" Grid.Column="2"

                        Command="{Binding KeyCommand,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"

                        CommandParameter="{Binding Path=Content,RelativeSource={RelativeSource Self}}"/>

                <Button Content="4" Grid.Row="1"

                        Command="{Binding KeyCommand,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"

                        CommandParameter="{Binding Path=Content,RelativeSource={RelativeSource Self}}"/>

                <Button Content="5" Grid.Row="1" Grid.Column="1"

                        Command="{Binding KeyCommand,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"

                        CommandParameter="{Binding Path=Content,RelativeSource={RelativeSource Self}}"/>

                <Button Content="6" Grid.Row="1" Grid.Column="2"

                        Command="{Binding KeyCommand,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"

                        CommandParameter="{Binding Path=Content,RelativeSource={RelativeSource Self}}"/>

                <Button Content="1" Grid.Row="2"

                        Command="{Binding KeyCommand,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"

                        CommandParameter="{Binding Path=Content,RelativeSource={RelativeSource Self}}"/>

                <Button Content="2" Grid.Row="2" Grid.Column="1"

                        Command="{Binding KeyCommand,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"

                        CommandParameter="{Binding Path=Content,RelativeSource={RelativeSource Self}}"/>

                <Button Content="3" Grid.Row="2" Grid.Column="2"

                        Command="{Binding KeyCommand,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"

                        CommandParameter="{Binding Path=Content,RelativeSource={RelativeSource Self}}"/>

                <Button Content="-" Grid.Row="3"

                        Command="{Binding KeyCommand,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"

                        CommandParameter="{Binding Path=Content,RelativeSource={RelativeSource Self}}"/>

                <Button Content="0" Grid.Row="3" Grid.Column="1"

                        Command="{Binding KeyCommand,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"

                        CommandParameter="{Binding Path=Content,RelativeSource={RelativeSource Self}}"/>

                <Button Content="." Grid.Row="3" Grid.Column="2"

                        Command="{Binding KeyCommand,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"

                        CommandParameter="{Binding Path=Content,RelativeSource={RelativeSource Self}}"/>

                <Button Content="Esc" Grid.Row="0" Grid.Column="3" Grid.RowSpan="2"  Margin="0,0,0,5" Width="56" Height="Auto" Padding="0"

                        Command="{Binding CloseCommand,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}" />

                <Button Grid.Row="2" Grid.Column="3" Grid.RowSpan="2" Height="auto" Width="56"  Margin="0 0 0 4" Padding="0"

                        Content="Enter"

                        Command="{Binding KeyCommand,RelativeSource={RelativeSource AncestorType={x:Type local:SoftKeyboardControl}}}"

                        CommandParameter="{Binding Path=Content,RelativeSource={RelativeSource Self}}"/>

            </Grid>

        </StackPanel>

    </StackPanel>

</UserControl>

3.2 Demo界面的代码

下附Demo界面后台代码。

/// <summary>

    /// TestWindow.xaml 的交互逻辑

    /// </summary>

    public partial class TestWindow : Window

    {

        public TestWindow()

        {

            InitializeComponent();

            softKeyboard.CloseCommand = new RoutedCommand();

            CommandBinding cmdBinding = new CommandBinding(softKeyboard.CloseCommand, CloseCommand_Excuted, CloseCommand_CanExcute);

            CommandBindings.Add(cmdBinding);

        }

        private void CloseCommand_CanExcute(object sender, CanExecuteRoutedEventArgs e)

        {

           e.CanExecute = popup.IsOpen;

        }

        private void CloseCommand_Excuted(object sender, ExecutedRoutedEventArgs e)

        {

            popup.IsOpen = false;

            textBox.Focus();

        }

        private void TextBox_GotFocus(object sender, RoutedEventArgs e)

        {

            popup.IsOpen = true;

        }

        private void TextBox_LostFocus(object sender, RoutedEventArgs e)

        {

            popup.IsOpen = false;

        }

    }

下附Demo界面的前台代码。

<Window x:Class="UI.View.TestWindow"

        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"

        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"

        mc:Ignorable="d"

        xmlns:view="clr-namespace:UI.View"

        Title="TestWindow" Height="800" Width="1400">

    <Grid x:Name="grid">

        <TextBox Margin="415,233,447,0" FontSize="30" Height="62"

                 VerticalContentAlignment="Center"  VerticalAlignment="Top"

                 GotFocus="TextBox_GotFocus" LostFocus="TextBox_LostFocus"  />

        <TextBox x:Name="textBox" Margin="470,343,503,364" />

        <Popup  x:Name="popup"

                StaysOpen="True"

                AllowsTransparency="True"

                PopupAnimation="Fade"

                PlacementTarget="{Binding ElementName = grid}"

                Placement="Bottom"

                HorizontalOffset="250"

                VerticalOffset="-280">

            <view:SoftKeyboardControl x:Name="softKeyboard"/>

        </Popup>

    </Grid>

</Window>

四 参考链接

虚拟键码 (Winuser.h) - Win32 apps | Microsoft Docs

keybd_event函数 （winuser.h） - Win32 应用|微软文档 (microsoft.com)

WPF实现软键盘 - 我是刹那、 - 博客园 (cnblogs.com)

WPF开发经验-实现Win10虚拟触摸键盘的相关教程结束。