Csharp 当输入的文本到达 TextBox 的右侧时，自动将文本滚动到 TextBox 内的左侧. C#、WPF、MVVM

我正在开发一个使用MVVM的WPF应用程序，用户需要将文本从TextBlock元素输入到文本框中.文本框的占位符被"填充"并定位在文本块的正上方.它有一个透明的背景.当用户输入文本时，他们到达TextBlock的右侧，接下来的单词将被隐藏.

我希望文本框自动滚动，以便最后输入的字符在文本框的左侧可见，允许用户看到他们下一步需要输入的内容.

以下是我使用的XAML代码:

<ScrollViewer
                x:Name="scroll"
                Grid.Row="1"
                HorizontalAlignment="Stretch"
                VerticalAlignment="Stretch"
                CanContentScroll="True"
                HorizontalScrollBarVisibility="Visible"
                VerticalScrollBarVisibility="Disabled">
                <Grid>
                    <Grid.RowDefinitions>
                        <RowDefinition />
                    </Grid.RowDefinitions>

                    <Border
                        Grid.Row="0"
                        HorizontalAlignment="Stretch"
                        VerticalAlignment="Stretch"
                        Background="#8EABAF">
                        <TextBlock
                            x:Name="tblTextToType"
                            Margin="2,0,0,0"
                            VerticalAlignment="Center"
                            AllowDrop="False"
                            FontFamily="/Fonts/Nunito_Sans/#NunitoSans"
                            FontSize="28"
                            Foreground="Gray"
                            TextAlignment="Center" />
                    </Border>

                    <TextBox
                        x:Name="tbTypedText"
                        Grid.Row="0"
                        HorizontalAlignment="Stretch"
                        VerticalAlignment="Stretch"
                        AllowDrop="False"
                        Background="Transparent"
                        FontFamily="/Fonts/Nunito_Sans/#NunitoSans"
                        FontSize="28"
                        Foreground="Black"
                        IsInactiveSelectionHighlightEnabled="True"
                        IsReadOnly="True"
                        IsUndoEnabled="False"
                        MaxLines="1"
                        SelectionBrush="Green">
                    </TextBox>
                </Grid>
            </ScrollViewer>

此外，我还将两个命令绑定到应用程序窗口以处理击键.如果输入的文本与TextBlock的内容匹配，则会以编程方式将其添加到TextBox中.

The Type method performs the required effect with scrolling text, but only after the first time the text exceeds the width of the TextBox, and I need it to happen after each such exceeding个

C#代码处理KeyDownCommand和KeyUpCommand命令:

public ICommand KeyDownCommand { get; private set; }
        private void ExecuteKeyDown(object? obj)
        {
            if (obj is KeyEventArgs e && _keyboardButtons.ContainsKey(e.Key))
            {
                Key key = (e.Key == Key.System) ? e.SystemKey : e.Key;
                _keyboardButtons[key].KeyGrid.Background = SecondColor;

                switch (key)
                {
                    case Key.LeftCtrl:
                    case Key.RightCtrl:
                    case Key.LWin:
                    case Key.RWin:
                    case Key.LeftAlt:
                    case Key.RightAlt:
                    case Key.Back:
                    case Key.Tab:
                    case Key.Enter:
                        return;

                    case Key.LeftShift:
                    case Key.RightShift:
                    case Key.CapsLock:
                        UpdateKeyboard();
                        return;

                    case Key.Space:
                        Type(' ');
                        return;

                    default:
                        Type(char.Parse(_keyboardButtons[key].Content.Text));
                        break;
                }

                return;
            }
        }
        public ICommand KeyUpCommand { get; private set; }
        private void ExecuteKeyUp(object? obj)
        {
            if (obj is KeyEventArgs e && _keyboardButtons.ContainsKey(e.Key))
            {
                _keyboardButtons[e.Key].KeyGrid.Background = Brushes.Transparent;
                UpdateKeyboard();
            }
        }

private bool isTextWidthExceededViewport = false;
private void Type(char character)
        {
            if (_textBox.Text.Length < _textBlock.Text.Length)
            {
                char expectedCharacter = _textBlock.Text[_textBox.Text.Length];

                if (character == expectedCharacter)
                {
                    _textBox.Text += character;

                    correctlyTypedTextLength++;
                    _progressBar.Value++;


                    _textBox.Foreground = (correctlyTypedTextLength == _textBox.Text.Length)
                        ? new SolidColorBrush(Colors.Black)
                        : new SolidColorBrush(Colors.Red);

                    _textBox.Select(0, correctlyTypedTextLength);

                    var typeface = new Typeface(_textBox.FontFamily, _textBox.FontStyle, _textBox.FontWeight, _textBox.FontStretch);
                    var formattedText = new FormattedText(_textBox.Text, Thread.CurrentThread.CurrentCulture, _textBox.FlowDirection, typeface, _textBox.FontSize, _textBox.Foreground);
                    var size = new Size(formattedText.Width, formattedText.Height);
                    if (size.Width + 20 > _scrollViewer.ViewportWidth && !isTextWidthExceededViewport)
                    {
                        _scrollViewer.ScrollToRightEnd();
                        isTextWidthExceededViewport = true;
                    }
                }
                else
                {
                    Fails++;
                    _textBox.Foreground = Brushes.Red;

                    if (Properties.Settings.Default.ErrorSound)
                        System.Media.SystemSounds.Exclamation.Play();
                }
            }
        }

我也try 过使用其他命令和自定义文本框元素来实现自动滚动，但没有成功.

总而言之，我的WPF应用程序需要一个文本框来自动滚动，以便当用户输入的内容超过文本框的可见宽度时，文本框左侧仍显示最后输入的字符.

如果有任何关于如何实现这种自动滚动行为的见解或解决方案，我将不胜感激.谢谢!