什么情况先需要使用ToString()？

Question

RT

Answer 1

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;namespace _1103
{
    public class Vehicle
    {
        private double _weight;        public double Weight
        {
            get { return _weight; }
            set { _weight = value; }
        }
        private int _count;        public int Count
        {
            get { return _count; }
            set { _count = value; }
        }
        public Vehicle()
        {
 
        }
        public Vehicle(double weight,int count)
        {
            _count = count;
            _weight = weight;
        }
    }
}
   using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;namespace _1103
{
    class Program
    {
        static void Main(string[] args)
        {
            Vehicle p = new Vehicle();
            Console.WriteLine(p.Weight.ToString() +p.Count.ToString());
            Vehicle p1 = new Vehicle(120.0, 4);
            Console.WriteLine("p1车的载重："+p1.Weight.ToString()    +"p1车的车轮："+ p1.Count.ToString());
            Vehicle p2 = new Vehicle(111,6);
            Console.WriteLine("p2车的载重："+p2.Weight.ToString()    +"p2车的车轮："+p2.Count.ToString());
            if (p1.Weight > p2.Weight)
            {
                Console.WriteLine("p1車載重大");
            }
            else
                Console.WriteLine("p2車載重大");
            
        }
    }
}
          
ps: Console.WriteLine("p1车的载重："+p1.Weight.ToString()    +"p1车的车轮："+ p1.Count.ToString());
            Vehicle p2 = new Vehicle(111,6);
            Console.WriteLine("p2车的载重："+p2.Weight.ToString()    +"p2车的车轮："+p2.Count.ToString());为什么要转换成string类型？

Answer 2

因为你p1 p2定义的不是string 类型。 而 Console.WriteLine()的内容一定要是字符串类型的 所以 要转换下。

Answer 3

convert.toString 与 Tostring 是不同的，Ｔostring里面没try catch. 在数据库取数据时，以防null
时还是别用tostring