我想生成一个从 1000 开始的用户 ID,为每个用户(1000、1001、1002 等)递增一个。两个位置似乎都没有播种随机语句......(在构造函数或主函数中)。为什么我的随机语句在以下代码中没有使用 1000 种子正确初始化?
public class Student
{
public string FullName { get; set; }
public int StudentID { get; set; }
//constructor to initialize FullName and StudentID
public Student(string name, int ID)
{
FullName = name;
Random rnd = new Random();
StudentID = rnd.Next(1000, 1050); // creates a number greater than 1000
return;
}
public override string ToString()
{
return string.Format("ID: {0}n Name: {1}", StudentID, FullName);
}
}
public class StudentTest
{
static void Main(string[] args)
{
Student student1 = new Student("Amy Lee", 1000);
Student student2 = new Student("John Williams", 1001);
Console.WriteLine(student1);
Console.WriteLine(student2);
Console.WriteLine("nPress any key to exit program");
Console.ReadKey();
}
}
Random
生成随机数,而不是顺序数。
声明一个 int
变量并为每个StudentID
递增它。
public class Student
{
public string FullName { get; set; }
public int StudentID { get; set; }
private static int _currentId = 1000;
public Student(string name)
{
FullName = name;
StudentID = _currentId++;
return;
}
public override string ToString()
{
return string.Format("ID: {0}n Name: {1}", StudentID, FullName);
}
}
我想生成一个从 1000 开始的用户 ID,每个用户递增一个(1000、1001、1002 等)。
然后,您不应该尝试使用随机生成器来执行此操作,因为它将返回随机数而不是序列号。
给定您的示例代码,其中 (1) 不使用线程,(2) 不使用数据库 (3) 并且不保存创建的Student
实例,实现所需内容的最简单方法如下:
public class Student
{
private static int _curID = 1000;
public static int GenerateNextID()
{
var id = _curID;
_curID++;
return id;
}
public string FullName { get; set; }
public int StudentID { get; private set; }
//constructor to initialize FullName and StudentID
public Student(string name, int ID)
{
FullName = name;
StudentID = ID;
}
public override string ToString()
{
return string.Format("ID: {0}n Name: {1}", StudentID, FullName);
}
}
并像这样使用它:
public class StudentTest
{
static void Main(string[] args)
{
Student student1 = new Student("Amy Lee", Student.GenerateNextID());
Student student2 = new Student("John Williams", Student.GenerateNextID());
Console.WriteLine(student1);
Console.WriteLine(student2);
Console.WriteLine("nPress any key to exit program");
Console.ReadKey();
}
}