如何：使用上下文菜单中的拼写检查功能

项目
08/18/2008

更新：2007 年 11 月

默认情况下，当在类似 TextBox 或 RichTextBox 这样的编辑控件中启用拼写检查功能时，可以在上下文菜单中获得拼写检查选项。例如，当用户右击一个拼错的单词时，会得到一组拼写建议或“全部忽略”选项。不过，当您用自己的自定义上下文菜单覆盖默认上下文菜单时，将会丢失此功能，而需要编写代码才能在上下文菜单中重新启用拼写检查功能。下面的示例演示如何在 TextBox 中启用此功能。

示例

下面的示例演示利用用于实现上下文菜单的某些事件创建 TextBox 的可扩展应用程序标记语言 (XAML)。

<Page x:Class="SDKSample.SpellerCustomContextMenu"
    xmlns="https://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="https://schemas.microsoft.com/winfx/2006/xaml"
    Loaded="OnWindowLoaded">

  <TextBox
    Name="myTextBox" 
    TextWrapping="Wrap"
    SpellCheck.IsEnabled="True"
    ContextMenuOpening="tb_ContextMenuOpening">
    In a custum menu you need to write code to add speler choices
    because everything in a custom context menu has to be added explicitly.
  </TextBox>

</Page>

下面的示例演示实现上下文菜单的代码。

using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Shapes;

namespace SDKSample
{
    public partial class SpellerCustomContextMenu : Page
    {

        void OnWindowLoaded(object sender, RoutedEventArgs e)
        {
            //This is required for the first time ContextMenu invocation so that TextEditor doesnt handle it.
            myTextBox.ContextMenu = GetContextMenu();
        }
        void tb_ContextMenuOpening(object sender, RoutedEventArgs e)
        {
            int caretIndex, cmdIndex;
            SpellingError spellingError;

            myTextBox.ContextMenu = GetContextMenu();
            caretIndex = myTextBox.CaretIndex;

            cmdIndex = 0;
            spellingError = myTextBox.GetSpellingError(caretIndex);
            if (spellingError != null)
            {
                foreach (string str in spellingError.Suggestions)
                {
                    MenuItem mi = new MenuItem();
                    mi.Header = str;
                    mi.FontWeight = FontWeights.Bold;
                    mi.Command = EditingCommands.CorrectSpellingError;
                    mi.CommandParameter = str;
                    mi.CommandTarget = myTextBox;
                    myTextBox.ContextMenu.Items.Insert(cmdIndex, mi);
                    cmdIndex++;
                }
                Separator separatorMenuItem1 = new Separator();
                myTextBox.ContextMenu.Items.Insert(cmdIndex, separatorMenuItem1);
                cmdIndex++;
                MenuItem ignoreAllMI = new MenuItem();
                ignoreAllMI.Header = "Ignore All";
                ignoreAllMI.Command = EditingCommands.IgnoreSpellingError;
                ignoreAllMI.CommandTarget = myTextBox;
                myTextBox.ContextMenu.Items.Insert(cmdIndex, ignoreAllMI);
                cmdIndex++;
                Separator separatorMenuItem2 = new Separator();
                myTextBox.ContextMenu.Items.Insert(cmdIndex, separatorMenuItem2);
            }
        }

        // Gets a fresh context menu. 
        private ContextMenu GetContextMenu()
        {
            ContextMenu cm = new ContextMenu();

            //Can create STATIC custom menu items if exists here...
            MenuItem m1, m2, m3, m4;
            m1 = new MenuItem();
            m1.Header = "File";
            m2 = new MenuItem();
            m2.Header = "Save";
            m3 = new MenuItem();
            m3.Header = "SaveAs";
            m4 = new MenuItem();
            m4.Header = "Recent Files";

            //Can add functionality for the custom menu items here...

            cm.Items.Add(m1);
            cm.Items.Add(m2);
            cm.Items.Add(m3);
            cm.Items.Add(m4);

            return cm;
        }

    }
}

用于在 RichTextBox 中执行上述操作的代码是类似的。主要区别在于传递给 GetSpellingError 方法的参数。对于 TextBox，传递的是插入符号位置的整数索引：

spellingError = myTextBox.GetSpellingError(caretIndex);

对于 RichTextBox，传递的是指定插入符号位置的 TextPointer：

spellingError = myRichTextBox.GetSpellingError(myRichTextBox.CaretPosition);