Question

尝试使用asp.net mvc时出现此错误

对于“ Contr1.Controllers.HomeController”中的方法“ System.Web.Mvc.ViewResult Index（Int32）”，参数字典包含一个非空类型“ System.Int32”的参数“ id”的空条目。可选参数必须是引用类型，可为空的类型，或者必须声明为可选参数。

namespace Contr1.Controllers
{
    public class HomeController : Controller
    {
        // GET: Home
        public ViewResult Index(int id)
        {
            EmployeeBusinessLayer employeeBL = new EmployeeBusinessLayer();
            Employee employee = employeeBL.GetEmployeDetails(175);

            ViewBag.Employee = employee; 
            ViewBag.Header = "Employee Details";
            return View();
        }
    }
}

namespace Contr1.Models
{
    public class EmployeeBusinessLayer
    {
        public Employee GetEmployeDetails(int EmployeeId)
        {
            Employee employee = new Employee()
            {
                Id = EmployeeId,
                Name = "aaaa",
                Gender = "Male",
                Address = "Alwal",
                City = "Hyderabad",
                Salary = 56431,
            };
            return employee;
        }
    }
}

我需要获取Web输出的详细信息，但是我正在获取可为空，引用或可选参数的值

Answer 1

您收到此错误，因为您需要一个id作为参数

公共ViewResult索引（int id）

尽管此时您不使用它，但仍然需要它。要么删除“ int id”，要么使id为空：

public ViewResult Index(int? id)

当我运行代码时，出现此错误

1 个答案: