如何在焦点和焦点丢失时自动切换输入语言

Question

我想为TextBox编写附加属性或行为，以便当焦点输入语言根据set属性自动更改时

任何人都可以为我提供示例代码来实现这一目标吗？

这是我到目前为止的代码，但是我想基于textBox焦点设置和取消设置语言，所以当TextBox焦点丢失时我想切换到在此类之前选择的inputlanguage这个类改变了它

    public static class InputLanguageSwitch
{
    #region Dependency properties
    /// <summary>
    /// language to switch to when input got focus
    /// </summary>
    public static readonly DependencyProperty KeyboardLanguageProperty = DependencyProperty.Register("KeyboardLanguage", typeof(string), typeof(Localization), new FrameworkPropertyMetadata(null, OnKeyboardLanguageChanged));

    #endregion

    #region Dependency properties Get/Set methods
    /// <summary>
    /// Return selected keyboard language
    /// </summary>
    /// <param name="d"></param>
    /// <returns></returns>
    public static string GetKeyboardLanguage(DependencyObject d)
    {
        return d.GetValue(KeyboardLanguageProperty) as string;
    }

    /// <summary>
    /// Set input language base on keyboard
    /// </summary>
    /// <param name="d"></param>
    /// <param name="value"></param>
    public static void SetKeyboardLanguage(DependencyObject d, string value)
    {
        d.SetValue(KeyboardLanguageProperty, value);
    }
    #endregion

    #region Even processing
    /// <summary>
    /// action to perform when input language changes
    /// </summary>
    /// <param name="d">Dependency object</param>
    /// <param name="e">DependencyPropertyChangedEventArgs</param>
    public static void OnKeyboardLanguageChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        if (!(d is TextBoxBase)) return;
        var textBox = d as TextBoxBase;
        var language = FindKeyboardLanguage((string) e.NewValue);
        if (string.IsNullOrEmpty((string) e.NewValue) | ReferenceEquals(language, CultureInfo.InvariantCulture))
        {
            //textBox.PreviewGotKeyboardFocus -= OnTextBoxPreviewGotKeyboardFocus;
            d.ClearValue(InputLanguageManager.InputLanguageProperty);
            d.ClearValue(InputLanguageManager.RestoreInputLanguageProperty);
        }
        else
        {
            //textBox.PreviewGotKeyboardFocus += OnTextBoxPreviewGotKeyboardFocus;
            d.SetValue(InputLanguageManager.InputLanguageProperty, language);
            d.SetValue(InputLanguageManager.RestoreInputLanguageProperty, true);
            InputLanguageManager.Current.CurrentInputLanguage = language;
        }
    }

    #endregion

    /// <summary>
    /// Find and return keyboard language if one specified as an argument
    /// is installed on machine
    /// </summary>
    /// <param name="tag">language tag</param>
    /// <returns><see cref="CultureInfo"/> for requested language></returns>
    public static CultureInfo FindKeyboardLanguage(string tag)
    {
        CultureInfo result = CultureInfo.InvariantCulture;
        if (!string.IsNullOrEmpty(tag))
        {
            if (InputLanguageManager.Current.AvailableInputLanguages != null)
                foreach (CultureInfo c in InputLanguageManager.Current.AvailableInputLanguages)
                {
                    if (c.IetfLanguageTag.ToUpper().StartsWith(tag.ToUpper()))
                    {
                        result = c;
                    }
                    if (c.IetfLanguageTag.ToUpper() == tag.ToUpper())
                    {
                        break; // TODO: might not be correct. Was : Exit For
                    }
                }
        }
        return result;
    }
}