ed.CurrentInputContext有误，请重新生成

非常抱歉我的回答有误。在 AutoCAD 中，获取当前输入上下文的方式应该是使用 `Editor.GetInputState()` 方法，而不是 `Editor.CurrentInputContext` 属性。以下是修改后的示例代码：

using Autodesk.AutoCAD.ApplicationServices;
using Autodesk.AutoCAD.EditorInput;

public class InputLanguageSwitcher
{
    [CommandMethod("SwitchInputLanguage")]
    public static void SwitchInputLanguage()
    {
        Document doc = Application.DocumentManager.MdiActiveDocument;
        Editor ed = doc.Editor;

        // 判断当前输入模式是否为命令行模式
        if (ed.GetInputState().IsInputPending)
        {
            // 切换输入法为英文
            System.Windows.Forms.InputLanguage.CurrentInputLanguage = System.Windows.Forms.InputLanguage.DefaultInputLanguage;
        }
        else
        {
            // 切换输入法为中文
            System.Windows.Forms.InputLanguage.CurrentInputLanguage = System.Windows.Forms.InputLanguage.InstalledInputLanguages[0];
        }
    }

    // 注册事件监听器，在文本框中输入内容时自动切换输入法
    public InputLanguageSwitcher()
    {
        Autodesk.AutoCAD.Internal.Utils.SetFocusToDwgView();
        Application.DocumentManager.DocumentActivated += DocumentManager_DocumentActivated;
    }

    private void DocumentManager_DocumentActivated(object sender, DocumentCollectionEventArgs e)
    {
        e.Document.Editor.SuspendInputQueue();
        e.Document.Editor.ImeModeChanged += Editor_ImeModeChanged;
        e.Document.Editor.ResumeInputQueue();
    }

    private void Editor_ImeModeChanged(object sender, EventArgs e)
    {
        Autodesk.AutoCAD.Internal.Utils.SetFocusToDwgView();
        System.Windows.Forms.InputLanguage.CurrentInputLanguage = System.Windows.Forms.InputLanguage.InstalledInputLanguages[0];
    }
}

再次感谢您的指正，希望这次的回答能够帮到您。