如何在SortedList中按特定条件查找/删除项目？

using System;
using System.Collections.Generic;
using System.Linq;

class Program
{
    static void Main()
    {
        SortedList<int, string> sortedList = new SortedList<int, string>();

        // 添加项目到SortedList
        sortedList.Add(1, "Apple");
        sortedList.Add(2, "Banana");
        sortedList.Add(3, "Orange");
        sortedList.Add(4, "Grapes");

        // 按特定条件查找项目
        int keyToFind = 2;
        if (sortedList.ContainsKey(keyToFind))
        {
            string value = sortedList[keyToFind];
            Console.WriteLine($"Found item with key {keyToFind}: {value}");
        }
        else
        {
            Console.WriteLine($"Item with key {keyToFind} not found");
        }

        string valueToFind = "Orange";
        if (sortedList.ContainsValue(valueToFind))
        {
            int key = sortedList.FirstOrDefault(x => x.Value == valueToFind).Key;
            Console.WriteLine($"Found item with value {valueToFind}: {key}");
        }
        else
        {
            Console.WriteLine($"Item with value {valueToFind} not found");
        }

        // 按特定条件删除项目
        int keyToDelete = 3;
        if (sortedList.ContainsKey(keyToDelete))
        {
            sortedList.Remove(keyToDelete);
            Console.WriteLine($"Item with key {keyToDelete} deleted");
        }
        else
        {
            Console.WriteLine($"Item with key {keyToDelete} not found");
        }

        string valueToDelete = "Grapes";
        if (sortedList.ContainsValue(valueToDelete))
        {
            int key = sortedList.FirstOrDefault(x => x.Value == valueToDelete).Key;
            sortedList.Remove(key);
            Console.WriteLine($"Item with value {valueToDelete} deleted");
        }
        else
        {
            Console.WriteLine($"Item with value {valueToDelete} not found");
        }
    }
}