Question

这些是我的主要课程

public class Customer
{
  public Customer()
  {
    Products = new HashSet<Product>();
  }
  public int Id { get; set; }
  public string Name { get; set; }

  public ICollection<Product> Products { get; set; }
}

public class Product
{
  public int Id { get; set; }
  public int CustomerId { get; set; }
  public string ProductName { get; set; }

  public Customer Customer { get; set; }
}

这些是我的观点模型

public class ProductVM
{
  public string ProductName { get; set; }
}

public class CustomerVM
{
  public string Name { get; set; }
  public ICollection<ProductVM> Products { get; set; }
}

如何填充CustomerVM的属性？

我尝试过这样的事情：

var tmp = _db.Customers.Select(c => new CustomerVM
{
  Name = c.Name,
  Products = ????? // I don't know how to populate here
}

asp.net mvc和linq中的新内容仍在向上发展。

Answer 1

这应该做的工作：

var tmp = _db.Customers.Select(c =>
    new CustomerVM
    {
        Name = c.Name,
        Products = c.Products.Select(p => new ProductVM { ProductName = p.ProductName }).ToList()
    }
)

Answer 2

访问Products媒体资源并使用ProductVM关键字创建Select的集合

var customerVm= _db.Customers
                   .Select(c => new CustomerVM
                                {
                                  Name = c.Name,
                                  Products = c.Products.
                                                  Select(s => 
                                    new ProductVM {ProductName= s.ProductName}).ToList()
                                });

Answer 3

如果Products已填充Customer：

Products = c.Products.Select(p => new ProductVM() { ProductName = p.ProductName } ).ToList()

如果不是：

Products = _db.Products.Where(p => p.CustomerId = c.Id)
    .Select(p => new ProductVM() { ProductName = p.ProductName } ).ToList()

Answer 4

如果您在客户类中进行ICollection，而在Product类中进行虚拟客户，则会自动链接它们。

public class Customer
{
  public Customer()
  {
    Products = new HashSet<Product>();
  }
  public int Id { get; set; }
  public string Name { get; set; }

  public virtual ICollection<Product> Products { get; set; }
}

public class Product
{
  public int Id { get; set; }
  public int CustomerId { get; set; }
  public string ProductName { get; set; }

  public virtual Customer Customer { get; set; }
}

如果你这样做，你可以用c.Products填充点数

如何在其中填充我的viewmodel属性？

4 个答案: