TupleStudy/TupleStudy/ValueTupleStudy.cs

using System;
using System.Collections.Generic;
using System.Text;

namespace TupleStudy
{
    /// <summary>
    ///  值元组 学习
    ///  ValueTuple是C# 7.0的新特性之一，.Net Framework 4.7以上版本可用, 其它版本可以用 nuget 添加System.ValueTuple
    ///  值元组也是一种数据结构，用于表示特定数量和元素序列，但是是和元组类不一样的，主要区别如下：
    ///  值元组是结构，是值类型，不是类，而元组（Tuple）是类，引用类型；
    ///  值元组元素是可变的，不是只读的，也就是说可以改变值元组中的元素值；
    ///  值元组的数据成员是字段不是属性。
    /// </summary>
    public class ValueTupleStudy
    {
        #region 构造函数 创建值元组

        /// <summary>
        /// 创建0元素的值元组
        /// </summary>
        public ValueTuple CreateValueTuple()
        {
            var tuple = new ValueTuple();

            return tuple;
        }

        /// <summary>
        /// 创建1元素的值元组
        /// </summary>
        public ValueTuple<T1> CreateValueTuple<T1>(T1 value)
        {
            var tuple = new ValueTuple<T1>(value);

            return tuple;
        }

        /// <summary>
        /// 创建2元素的值元组
        /// </summary>
        public ValueTuple<T1,T2> CreateValueTuple<T1,T2>(T1 value1, T2 value2)
        {
            var tuple = new ValueTuple<T1, T2>(value1, value2);

            return tuple;
        }

        /// <summary>
        /// 创建3元素的值元组
        /// </summary>
        public ValueTuple<T1, T2, T3> CreateValueTuple<T1, T2, T3>(T1 value1, T2 value2, T3 value3)
        {
            var tuple = new ValueTuple<T1, T2, T3>(value1, value2, value3);

            return tuple;
        }

        /// <summary>
        /// 创建4元素的值元组
        /// </summary>
        public ValueTuple<T1, T2, T3, T4> CreateValueTuple<T1, T2, T3, T4>(T1 value1, T2 value2, T3 value3, T4 value4)
        {
            var tuple = new ValueTuple<T1, T2, T3, T4>(value1, value2, value3, value4);

            return tuple;
        }

        /// <summary>
        /// 创建5元素的值元组
        /// </summary>
        public ValueTuple<T1, T2, T3, T4, T5> CreateValueTuple<T1, T2, T3, T4, T5>(T1 value1, T2 value2, T3 value3, T4 value4, T5 value5)
        {
            var tuple = new ValueTuple<T1, T2, T3, T4, T5>(value1, value2, value3, value4, value5);

            return tuple;
        }

        /// <summary>
        /// 创建6元素的值元组
        /// </summary>
        public ValueTuple<T1, T2, T3, T4, T5, T6> CreateValueTuple<T1, T2, T3, T4, T5, T6>(T1 value1, T2 value2, T3 value3, T4 value4, T5 value5, T6 value6)
        {
            var tuple = new ValueTuple<T1, T2, T3, T4, T5, T6>(value1, value2, value3, value4, value5, value6);

            return tuple;
        }

        /// <summary>
        /// 创建7元素的值元组
        /// </summary>
        public ValueTuple<T1, T2, T3, T4, T5, T6, T7> CreateValueTuple<T1, T2, T3, T4,T5,T6,T7>(T1 value1, T2 value2, T3 value3, T4 value4, T5 value5, T6 value6, T7 value7)
        {
            var tuple = new ValueTuple<T1, T2, T3, T4, T5, T6, T7>(value1, value2, value3, value4, value5, value6, value7);

            return tuple;
        }

        /// <summary>
        /// 创建8元素的值元组
        /// </summary>
        public ValueTuple<T1, T2, T3, T4, T5, T6, T7, TRest> CreateValueTuple<T1, T2, T3, T4, T5, T6, T7, TRest>(T1 value1, T2 value2, T3 value3, T4 value4, T5 value5, T6 value6, T7 value7, TRest restValue) where TRest : struct
        {
            var tuple = new ValueTuple<T1, T2, T3, T4, T5, T6, T7, TRest>(value1, value2, value3, value4, value5, value6, value7, restValue);

            return tuple;
        }
        #endregion

        #region 静态Create方法 创建值元组

        /// <summary>
        /// 创建0元素的值元组
        /// </summary>
        public ValueTuple GetValueTuple()
        {
            var tuple = ValueTuple.Create();
            return tuple;
        }

        /// <summary>
        /// 创建1元素的值元组
        /// </summary>
        public ValueTuple<T1> GetValueTuple<T1>(T1 item1)
        {
            var tuple = ValueTuple.Create(item1);
            return tuple;
        }

        /// <summary>
        /// 创建2元素的值元组
        /// </summary>
        public ValueTuple<T1, T2> GetValueTuple<T1, T2>(T1 item1, T2 item2)
        {
            var tuple = ValueTuple.Create(item1, item2);
            return tuple;
        }

        /// <summary>
        /// 创建3元素的值元组
        /// </summary>
        public ValueTuple<T1, T2, T3> GetValueTuple<T1, T2, T3>(T1 item1, T2 item2, T3 item3)
        {
            var tuple = ValueTuple.Create(item1, item2, item3);
            return tuple;
        }

        /// <summary>
        /// 创建4元素的值元组
        /// </summary>
        public ValueTuple<T1, T2, T3, T4> GetValueTuple<T1, T2, T3, T4>(T1 item1, T2 item2, T3 item3, T4 item4)
        {
            var tuple = ValueTuple.Create(item1, item2, item3, item4);
            return tuple;
        }

        /// <summary>
        /// 创建5元素的值元组
        /// </summary>
        public ValueTuple<T1, T2, T3, T4, T5> GetValueTuple<T1, T2, T3, T4, T5>(T1 item1, T2 item2, T3 item3, T4 item4, T5 item5)
        {
            var tuple = ValueTuple.Create(item1, item2, item3, item4, item5);
            return tuple;
        }

        /// <summary>
        /// 创建6元素的值元组
        /// </summary>
        public ValueTuple<T1, T2, T3, T4, T5, T6> GetValueTuple<T1, T2, T3, T4, T5, T6>(T1 item1, T2 item2, T3 item3, T4 item4, T5 item5, T6 item6)
        {
            var tuple = ValueTuple.Create(item1, item2, item3, item4, item5, item6);
            return tuple;
        }

        /// <summary>
        /// 创建7元素的值元组
        /// </summary>
        public ValueTuple<T1, T2, T3, T4, T5, T6, T7> GetValueTuple<T1, T2, T3, T4, T5, T6, T7>(T1 item1, T2 item2, T3 item3, T4 item4, T5 item5, T6 item6, T7 item7)
        {
            var tuple = ValueTuple.Create(item1, item2, item3, item4, item5, item6, item7);
            return tuple;
        }

        /// <summary>
        /// 创建8元素的值元组
        /// </summary>
        public (T1, T2, T3, T4, T5, T6, T7, TRest) GetValueTuple<T1, T2, T3, T4, T5, T6, T7, TRest>(T1 item1, T2 item2, T3 item3, T4 item4, T5 item5, T6 item6, T7 item7, TRest item8) where TRest:struct
        {
            var tuple = ValueTuple.Create(item1, item2, item3, item4, item5, item6, item7, item8);
            return tuple;
        }
        #endregion

        #region 优化：解构ValueTuple

        //注意：通过var (x, y)或者(var x, var y)来解析值元组元素构造局部变量，
        //同时可以使用符号”_”来忽略不需要的元素。

        /// <summary>
        /// 简化值元组创建语法
        /// </summary>
        public (int userId, string userName, int userAge) SingleCreateValueTuple()
        {
            //回为函数返回值已经重命名，创建时再次命名已没有意义
            //return (userId: 1, userName: "wanggaofeng", userAge: 18);

            return (1, "王高峰",18);
        }
        #endregion

        #region 方法返回多个值

        /// <summary>
        /// 方法返回一组定义了类型并已经命名的数据
        /// </summary>
        /// <returns>
        /// 定义了类型并已经命名的一组数据
        /// </returns>
        public (int userId, string userName, uint userAge) GetNamedValueTuple()
        {
            var tuple = ValueTuple.Create<int, string, uint>(1, "王高峰", 18);
            return tuple;
        }

        /// <summary>
        /// 方法返回一组只定义，未命名的的数据
        /// </summary>
        /// <returns>
        /// 只定义类型，未命名的一组数据
        /// </returns>
        public (int, string, uint) GetUnNamedValueTuple()
        {
            var tuple = ValueTuple.Create<int, string, uint>(1, "王高峰", 18);
            return tuple;
        }
        #endregion

        #region ValueTuple做为方法的参数

        /// <summary>
        /// ValueTuple做为方法的参数
        /// </summary>
        public bool ValueTupleAsParameterForMether(object valueTuple)
        {
            try
            {
                var student = (ValueTuple<int, string, int>)valueTuple;
                return true;
            }
            catch
            {
                return false;
            }
        }
        #endregion
    }
}