关于switch表达式的错误(必须是bool、char、string等)

Question

我正在给我的程序添加一个语音控制功能。我的代码有一个错误，我似乎无法摆脱这个错误。语音控制将允许用户在不使用鼠标或键盘的情况下控制程序的各个方面。

目前，我的代码包括：

using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.IO;
using System.Drawing.Text;
using System.Drawing.Printing;
using System.Diagnostics;
using System.Linq;
using System.Reflection;
using FontCombo;
using System.Speech.Recognition;
using System.Speech.Recognition.SrgsGrammar;
using Microsoft.VisualBasic;

if (voctrl.Checked == true)
        {
            vcstat.Text = "Voice Control Enabled";
            recognizer = new SpeechRecognizer();
            recognizer.SpeechDetected += recognizer_SpeechDetected;
            recognizer.SpeechRecognitionRejected += recognizer_SpeechRecognitionRejected;
            recognizer.SpeechRecognized += recognizer_SpeechRecognized;
            GrammarBuilder grammar = new GrammarBuilder();
            grammar.Append(new Choices("Cut", "Copy", "Paste", "Select All", "Print", "Deselect All", "Delete", "Save", "Save As", "Open", "New", "Close"));
            recognizer.LoadGrammar(new Grammar(grammar));
        }
        else
        {
            vcstat.Text = "Voice Control Disabled";
        }

private void recognizer_SpeechRecognized(object sender, SpeechRecognizedEventArgs e)
    {
        if (voctrl.Checked == true)
        {
            switch (e.Result.Text.ToUpper) //This is the error according to Visual Studio
            {
                case
                "Cut":
                    Clipboard.SetText(richTextBoxPrintCtrl1.SelectedRtf, TextDataFormat.Rtf);
                    richTextBoxPrintCtrl1.SelectedRtf = "";
                    break; // etc.

我已经尝试在互联网上搜索一个解决方案，但似乎找不到一个与此代码一起工作。我做错了什么？如果我很愚蠢，我很抱歉，但我对C#和编程一般都是新手。

错误如下:错误4 switch表达式或case标签必须是bool、char、string、integral、enum或相应的可以为enum的类型

Answer 1

ToUpper应为方法ToUpper()，缺少括号