代码

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
//输入用户名
Console.WriteLine("请输入用户名");

    string yonghuming = Console.ReadLine();

    //输入密码
    Console.WriteLine("请输入密码");

    string mima = Console.ReadLine();

    bool b = yonghuming == "admin" && mima == "mypass";
    if (b)
    {
        Console.WriteLine("登录成功");
        Console.ReadKey();

    }

}

}
}

效果

QQ图片20181031191851.png