模型绑定从 2.2 更改为 3.0 Asp.NetCore

Question

I am attempting to hit an endpoint on a 3.0 api. I am passing in all parameters the same way the existing application does using a dictionary of type string, string. But now i am getting a 400 bad request and it is because of the property UserId is an int.

public class ConfirmCreatedRequest
{
    public int UserId { get; set; }
    public string Password { get; set; }
    public string MemorableWord { get; set; }
}

Here is an example of the json using the original dictionary and changing the dictionary to string, object.

"{\"UserId\":\"90744\",\"Password\":\"\",\"MemorableWord\":\"\"}"
"{\"UserId\":90750,\"Password\":\"\",\"MemorableWord\":\"\"}"

The thing is i do not want to do this as it not type safe.

I want to know what has changed in 3.0 and has it been fixed in 3.0.1

Answer 1

The default serializer has changed from Newtonsoft.Json to System.Text.Json , so some of the serialization behaviours will change.

If you want it to behave like it did in 2.x you can make Newtonsoft.Json the default with:

services.AddMvc()
    .AddNewtonsoftJson();

See the docs here: https://docs.microsoft.com/en-us/aspnet/core/migration/22-to-30?view=aspnetcore-3.0&tabs=visual-studio#jsonnet-support

If you want to make your current JSON and type serialize/deserialize as they have done with the new System.Text.Json , you can read up here: https://github.com/dotnet/corefx/issues/39473

This issue was raised by Stackoverflows Nick Craver, in it there are custom converters that give you what you want, and an indication that there is a plan to support "looser" deserialization in 5.0 .