我目前正在编写一个程序，我必须这样做 1）为用户提供一些选择：1。按名称搜索？ 2.按出生日期搜索？ 2）如果用户按名称选择搜索，请让他们输入名字然后给出输出 3）如果用户按出生日期选择搜索，请让他们以格式（MM / DD / YYYY）输出出生日期，然后给出输出。
如果验证失败或无法找到数据，我必须重复选项。 我正在努力重复选项的概念。非常感谢ANy的帮助。
到目前为止我的代码
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace Week2Tutorial
{
class Program
class Student
{
public int Id { get; set; }
public string FirstName { get; set; }
public string Lastname { get; set; }
public DateTime DOB { get; set; }
public string Gender { get; set; }
}
static void Main(string[] args)
{
var students = new List<Student>()
{
new Student() { Id = 1,FirstName = "Min Chul",Lastname = "Shin",DOB = new DateTime(2010,01,01),Gender = "Male"},
new Student() { Id = 2,FirstName = "Nicky", Lastname = "Lauren", DOB = new DateTime(2009, 01, 01), Gender = "Female"},
new Student() { Id = 3, FirstName = "Amy", Lastname = "Park", DOB = new DateTime(2008, 01, 01), Gender = "Female" },
new Student() { Id = 4, FirstName = "Aurelie", Lastname = "Adair", DOB = new DateTime(2007, 01, 01), Gender = "Female" }
};
//foreach (var x in students)
//{
// Console.WriteLine("Id = {0}, FirstName = {1}, Lastname = {2}, DOB = {3}, Gender = {4}",x.Id,x.FirstName,x.Lastname,x.DOB,x.Gender);
//}
Console.WriteLine(" Please Choose one of the options:");
Console.WriteLine("1> Search by first name");
Console.WriteLine("2> Search by date of birth");
switch ( Convert.ToInt32(Console.ReadLine()))
{
case 1:
Console.WriteLine("You choose:1");
Console.WriteLine("Type your first name:");
var a = Console.ReadLine();
var case1 = students.Where(x=>x.FirstName==a);
if (case1.Count()!=0)
{
Console.WriteLine("Found! Here are the details:");
foreach (var x in case1)
{
Console.WriteLine("Name: {0}{1} D.O.B:{2} and Gender{3}", x.FirstName, x.Lastname, x.DOB, x.Gender);
}
}
else
{
Console.WriteLine(" Enter the correct information");
}
break;
case 2:
Console.WriteLine("You choose:2");
Console.WriteLine("Enter your Date of Birth in format MM/DD/YYYY:");
var b = DateTime.Parse(Console.ReadLine());
//Console.WriteLine(b);
//Console.ReadLine();
var case2 = students.Where(x => x.DOB == b);
if (case2.Count() != 0)
{
Console.WriteLine("Found! Here are your details");
foreach (var x in case2)
{
Console.WriteLine("Name:{0} {1} DOB:{2} Gender:{3}", x.FirstName, x.Lastname, x.DOB, x.Gender);
}
}
else
{
Console.WriteLine(" Enter the correct information");
}
break;
default:
Console.WriteLine("Please enter the valid option");
break;
}
}
}
}
答案 0 :(得分：1)
可以完成do while循环这里是do while Loop
的一般语法do {
code to be executed;
} while (condition is true);
什么是while循环它是一个无限循环，执行代码直到条件为真。 在你的情况下，我们正在采用一个新的变量临时温度，这意味着零意味着没有 结果如果你的任何一个switch case变为true并根据用户的搜索查询找到结果，那么结果的计数将被复制到temp变量，现在temp不再有零值意味着condition为false意味着代码不会再次执行
你只需要开始一个无限循环，直到条件为真
do{
var temp=0; ///Temporary variable to check the result count
//intially variable b will be zero because INtially result count is zero
Console.WriteLine(" Please Choose one of the options:");
Console.WriteLine("1> Search by first name");
Console.WriteLine("2> Search by date of birth");
switch ( Convert.ToInt32(Console.ReadLine()))
{
case 1:
Console.WriteLine("You choose:1");
Console.WriteLine("Type your first name:");
var a = Console.ReadLine();
var case1 = students.Where(x=>x.FirstName==a);
temp=case1.Count(); //Getting result count in another variable
if (case1.Count()!=0)
{
Console.WriteLine("Found! Here are the details:");
foreach (var x in case1)
{
Console.WriteLine("Name: {0}{1} D.O.B:{2} and Gender{3}", x.FirstName, x.Lastname, x.DOB, x.Gender);
}
}
else
{
Console.WriteLine(" Enter the correct information");
}
break;
case 2:
Console.WriteLine("You choose:2");
Console.WriteLine("Enter your Date of Birth in format MM/DD/YYYY:");
var b = DateTime.Parse(Console.ReadLine());
//Console.WriteLine(b);
//Console.ReadLine();
var case2 = students.Where(x => x.DOB == b);
temp=case2.Count(); //Getting result count in another variable
if (case2.Count() != 0)
{
Console.WriteLine("Found! Here are your details");
foreach (var x in case2)
{
Console.WriteLine("Name:{0} {1} DOB:{2} Gender:{3}", x.FirstName, x.Lastname, x.DOB, x.Gender);
}
}
else
{
Console.WriteLine(" Enter the correct information");
}
break;
default:
Console.WriteLine("Please enter the valid option");
break;
}
}while(temp==0); ////Endless Loop while result is zero
intially temp等于零表示结果计数为零 所以它会再次启动循环但是如果有任何结果 这意味着temp不等于零，它不会执行代码
答案 1 :(得分：0)
只需使用while循环。
示例来自：https://www.dotnetperls.com/console-readline
using System;
class Program
{
static void Main()
{
while (true) // Loop indefinitely
{
Console.WriteLine("Enter input:"); // Prompt
string line = Console.ReadLine(); // Get string from user
if (line == "exit") // Check string
{
break;
}
Console.Write("You typed "); // Report output
Console.Write(line.Length);
Console.WriteLine(" character(s)");
}
}
}