WPF textbox InputMethod.IsInputMethodEnabled="False" conn't work in Word customTaskPane

Question

I have a vsto program，I'm going to show a text box in CustomTaskPane

I set the disable input method, but it doesn't work

<TextBox InputMethod.IsInputMethodEnabled="False" ></TextBox>

But in the pop-up box of the CustomTaskPane control, the code is valid

Answer 1

The outer focus of ElementHost will be interfering with IsInputMethodEnabled In ElementHost.

This problem may be improved by set IsInputMethodEnabled property when the text box got focus.

namespace WordAddIn1
{
    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Xml.Linq;
    using Word = Microsoft.Office.Interop.Word;
    using Office = Microsoft.Office.Core;
    using Microsoft.Office.Tools.Word;
    using Microsoft.Office.Tools.Ribbon;

    using System.Windows;
    using System.Windows.Data;
    using System.Windows.Controls;
    using System.Windows.Input;

    public partial class Ribbon1
    {
        private void Ribbon1_Load(object sender, RibbonUIEventArgs e)
        {
        }

        private void button1_Click(object sender, RibbonControlEventArgs e)
        {
            if (Globals.ThisAddIn.CustomTaskPanes.Count != 0)
            {
                return;
            }

            var usercontrolForm = new System.Windows.Forms.UserControl();
            var host = new System.Windows.Forms.Integration.ElementHost() { Dock = System.Windows.Forms.DockStyle.Fill };
            usercontrolForm.Controls.Add(host);

            StackPanel stack = new StackPanel();

            for (int i = 0; i < 2; i++)
            {
                bool imeEnable = i == 1;

                var textBox = new TextBox() { Margin = new Thickness(5), Text = $"Enabled={imeEnable}" };

                ElementHostInputMethodTool.SetIsInputMethodEnabled(textBox, imeEnable);

                stack.Children.Add(textBox);
            }

            var userControlWPF = new System.Windows.Controls.UserControl();
            userControlWPF.Content = stack;

            host.Child = userControlWPF;

            var pane = Globals.ThisAddIn.CustomTaskPanes.Add(usercontrolForm, "Test");
            pane.Visible = true;
        }
    }

    class ElementHostInputMethodTool
    {
        public static bool GetIsInputMethodEnabled(System.Windows.Controls.Primitives.TextBoxBase obj)
        {
            return (bool)obj.GetValue(IsInputMethodEnabledProperty);
        }

        public static void SetIsInputMethodEnabled(System.Windows.Controls.Primitives.TextBoxBase obj, bool value)
        {
            obj.SetValue(IsInputMethodEnabledProperty, value);
        }

        public static readonly DependencyProperty IsInputMethodEnabledProperty =
            DependencyProperty.RegisterAttached
            ("IsInputMethodEnabled"
            , typeof(bool)
            , typeof(ElementHostInputMethodTool)
            , new PropertyMetadata(true, (sender, e) =>
            {
                var textBox = (System.Windows.Controls.Primitives.TextBoxBase)sender;
                bool isEnable = (bool)e.NewValue;
                if (isEnable)
                {
                    textBox.GotKeyboardFocus -= TextBox_GotKeyboardFocus;
                }
                else
                {
                    textBox.GotKeyboardFocus += TextBox_GotKeyboardFocus;
                }

                InputMethod.SetIsInputMethodEnabled(textBox, isEnable);
            }));

        private static void TextBox_GotKeyboardFocus(object sender, KeyboardFocusChangedEventArgs e)
        {
            var textBox = (System.Windows.Controls.Primitives.TextBoxBase)sender;
            bool isImeEnable = GetIsInputMethodEnabled(textBox);

            // set IsInputMethodEnabled property when got focus
            InputMethod.SetIsInputMethodEnabled(textBox, isImeEnable);
        }
    }

}