c#.net在一个richtextbox中用listbox实现c++代码自动提示

实现 C++ 代码自动提示的方式与实现 C# 代码自动提示的方式类似。以下是一个简单的示例代码，可以实现在 RichTextBox 中输入 C++ 代码时，根据当前光标所在行的文本自动提示相关的 C++ 关键字和标识符：

private void richTextBox1_TextChanged(object sender, EventArgs e)
{
    // 获取当前光标所在行的文本
    int index = richTextBox1.SelectionStart;
    int line = richTextBox1.GetLineFromCharIndex(index);
    string text = richTextBox1.Lines[line];

    // 根据文本获取匹配的代码提示列表
    List<string> suggestions = GetSuggestions(text);

    // 清空 ListBox，并添加提示项
    listBox1.Items.Clear();
    listBox1.Items.AddRange(suggestions.ToArray());

    // 显示 ListBox
    if (suggestions.Count > 0)
    {
        listBox1.Visible = true;
        listBox1.Width = richTextBox1.Width;
        listBox1.Top = richTextBox1.Top + (line + 1) * richTextBox1.Font.Height;
        listBox1.Left = richTextBox1.Left;
    }
    else
    {
        listBox1.Visible = false;
    }
}

private void listBox1_SelectedIndexChanged(object sender, EventArgs e)
{
    // 将选中的提示项插入到 RichTextBox 中
    int index = richTextBox1.SelectionStart;
    int line = richTextBox1.GetLineFromCharIndex(index);
    int start = richTextBox1.GetFirstCharIndexFromLine(line);
    int length = index - start;
    string suggestion = listBox1.SelectedItem.ToString();
    richTextBox1.SelectionStart = start;
    richTextBox1.SelectionLength = length;
    richTextBox1.SelectedText = suggestion;
    listBox1.Visible = false;
}

private List<string> GetSuggestions(string text)
{
    // 根据文本获取匹配的代码提示列表
    List<string> suggestions = new List<string>();
    if (text.StartsWith("#"))
    {
        // C++ 预处理指令
        suggestions.Add("#define");
        suggestions.Add("#include");
        suggestions.Add("#ifdef");
        suggestions.Add("#ifndef");
        suggestions.Add("#endif");
    }
    else if (text.EndsWith("."))
    {
        // C++ 命名空间
        suggestions.Add("std");
    }
    else
    {
        // C++ 关键字和标识符
        suggestions.Add("auto");
        suggestions.Add("break");
        suggestions.Add("case");
        suggestions.Add("char");
        suggestions.Add("class");
        suggestions.Add("const");
        suggestions.Add("continue");
        suggestions.Add("default");
        suggestions.Add("delete");
        suggestions.Add("do");
        suggestions.Add("double");
        suggestions.Add("else");
        suggestions.Add("enum");
        suggestions.Add("extern");
        suggestions.Add("float");
        suggestions.Add("for");
        suggestions.Add("friend");
        suggestions.Add("goto");
        suggestions.Add("if");
        suggestions.Add("inline");
        suggestions.Add("int");
        suggestions.Add("long");
        suggestions.Add("mutable");
        suggestions.Add("namespace");
        suggestions.Add("new");
        suggestions.Add("operator");
        suggestions.Add("private");
        suggestions.Add("protected");
        suggestions.Add("public");
        suggestions.Add("register");
        suggestions.Add("return");
        suggestions.Add("short");
        suggestions.Add("signed");
        suggestions.Add("sizeof");
        suggestions.Add("static");
        suggestions.Add("struct");
        suggestions.Add("switch");
        suggestions.Add("template");
        suggestions.Add("this");
        suggestions.Add("throw");
        suggestions.Add("try");
        suggestions.Add("typedef");
        suggestions.Add("typeid");
        suggestions.Add("typename");
        suggestions.Add("union");
        suggestions.Add("unsigned");
        suggestions.Add("using");
        suggestions.Add("virtual");
        suggestions.Add("void");
        suggestions.Add("volatile");
        suggestions.Add("wchar_t");
        suggestions.Add("while");
    }
    return suggestions;
}

需要注意的是，上述示例只是为了演示实现 C++ 代码自动提示的思路，实际应用中需要根据 C++ 语法规则和标准库的使用情况来生成代码提示列表。