Why BindNever attribute doesn't work

Question

I do not want do bind the Id property on my CustomerViewModel so I added a [BindNever] attribute but it is not working. What could be the solution?

I have the following:

CustomerController.cs

// PUT api/customers/5
[HttpPut("{id}")]
public async Task<IActionResult> Put([FromUri] int id, [FromBody]CustomerViewModel customer)
{
  //Implementation
}

CustomerViewModel

public class CustomerViewModel
{
    [BindNever]
    public int Id { get; set; }
    public string LastName { get; set; }
    public string FirstName { get; set; }
    public string Email { get; set; }
}

If I input the following json . The id property still gets binded

{
  "id": 100,
  "lastName": "Bruce",
  "firstName": "Wayne",
  "email": "[email protected]"
}

Answer 1

I add a note.

Now it's officially explained by Microsoft.

https://docs.microsoft.com/ja-jp/aspnet/core/mvc/models/model-binding?view=aspnetcore-6.0#attributes-for-complex-type-targets

https://docs.microsoft.com/ja-jp/aspnet/core/mvc/models/model-binding?view=aspnetcore-6.0#input-formatters

https://docs.microsoft.com/ja-jp/aspnet/core/mvc/models/model-binding?view=aspnetcore-6.0#frombody-attribute

In summary,

If we use the “FromBody attribute (including defaults such as HttpPost attribute)”, it depends on the input formatter and the BindNever attribute etc. will not work.

Instead, we can do so by specifying the attribute that corresponds to the input formatter. For example, for the default json It can be ignored using "System.Text.Json.Serialization.JsonIgnoreAttribute".