Question

我正在尝试使用元组，因此我可以在同一个视图中使用2个模型，我在控制器中执行了此操作：

public ActionResult Index( int id = 0 )
{
    int lastVoyageID = entities.log_voyage.Max(item => item.Num_Voy);

    var first = entities.log_voyage.Where(v => v.Num_Voy == lastVoyageID);
    log_voyage voyage1 = entities.log_voyage.Find(lastVoyageID);
    var second = entities.log_ligne_voyage.Where(x => x.NUM_Voy == lastVoyageID).ToList();
    var t = new Tuple<log_voyage, log_ligne_voyage>(first, second);
    return View(t);
}

但我得到了这个：

我不知道该怎么办？我如何使用元组？

这是错误：

无法将system.Linq.IQueryable转换为WebApplication.Models.log_voyage

Answer 1

var first = entities.log_voyage.Where(v => v.Num_Voy == lastVoyageID)返回集合，但是Tuple期望单个对象，所以它应该是;

var first = entities.log_voyage.Where(v => v.Num_Voy == lastVoyageID).FirstOrDefault()

此表达式返回集合，而Tuple再次寻找一个对象

var second = entities.log_ligne_voyage.Where(x => x.NUM_Voy == lastVoyageID).ToList()

您可能希望将元组签名更改为Tuple<log_voyage, List<log_ligne_voyage>>

最后，

public ActionResult Index( int id = 0 )
{

    int lastVoyageID = entities.log_voyage.Max(item => item.Num_Voy);

    var first = entities.log_voyage.Where(v => v.Num_Voy == lastVoyageID).FirstOrDefault();
    log_voyage voyage1 = entities.log_voyage.Find(lastVoyageID);
    var second = entities.log_ligne_voyage.Where(x => x.NUM_Voy == lastVoyageID).ToList();
    var t = new Tuple<log_voyage, List<log_ligne_voyage>>(first, second);
    return View(t);

}

如何在MVC 5

1 个答案: