表达式树，用于创建用于生成c#字典的lambda

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

class Program
{
    static void Main()
    {
        // 创建一个用于生成C#字典的Lambda表达式
        Expression<Func<Dictionary<string, int>>> expression = () => new Dictionary<string, int>
        {
            { "key1", 1 },
            { "key2", 2 },
            { "key3", 3 }
        };

        // 编译并执行表达式树
        var compiledExpression = expression.Compile();
        var dictionary = compiledExpression();

        // 输出字典的内容
        foreach (var kvp in dictionary)
        {
            Console.WriteLine($"Key: {kvp.Key}, Value: {kvp.Value}");
        }
    }
}