渲染局部视图时，对象引用未设置为实例

Question

getting object reference exception when i try to render a partial view of different controller.

main view

@model Models.Users

--------
@Html.Partial("~/Views/Address/AddressCreate.cshtml",Model.address)
--------

this is action

   public ActionResult Create()
    {
        var model = new Users();
        return  View(model);
    }

partial view

@model Models.Address
<div>@Html.TextBoxFor(m=>m.AddressLine1)</div>

partial view

  public ActionResult AddressCreate()
    {
        var model = new Address();

        return PartialView(model);
    }

User and address class

public class Users
{
 public Address address {get; set;}

 }
 public class Address
  {
      // address objects
  }

Answer 1

It appears that the address property on your Users model is null when you passed it to the main view.

So make sure that this isn't the case by explicitly initializing it:

public ActionResult Create()
{
    var model = new Users();
    model.address = new Address();
    return View(model);
}

Or alternatively you could do that in your model's constructor:

public class Users
{
    public Users()
    {
        this.address = new Address();
    }

    public Address address { get; set; }
}

This being said, there's also some strange thing I've noticed in your code. You seem to have declared some AddressCreate controller action which is never used because you rendered the partial with the Html.Partial helper. If you wanted to render the partial using a child action then you should definitely use the Html.Action helper instead:

@model Models.Users

--------
@Html.Action("AddressCreate")
--------

Now the AddressCreate action will be invoked and successfully populate the Address model to the corresponding partial. In this case you no longer need to explicitly instantiate the address property on your main view model because it will never be used.

Just make sure you understand the differences between Html.Partial and Html.Action helpers.

Answer 2

As it is, the code will not be calling AddressCreate and hence never setting up the Address view model.
Furthermore, your Create method does not populate an Address into the User it returns.

You need to either 1)Populate the User's address in the create method (and get rid of the AddressCreate method).

Or

2)Use Html.Action instead of Html.Partial in your view, to call your AddressCreate method.