Bind query parameters to a model in ASP.NET Core

问题

I am trying to use model binding from query parameters to an object for searching.

My search object is

[DataContract]
public class Criteria 
{
  [DataMember(Name = "first_name")]
  public string FirstName { get; set; }
}

My controller has the following action

[Route("users")]
public class UserController : Controller 
{
  [HttpGet("search")]
  public IActionResult Search([FromQuery] Criteria criteria)
  {
    ...
  }
}

When I call the endpoint as follows .../users/search?first_name=dave the criteria property on the controller action is null. However, I can call the endpoint not as snake case .../users/search?firstName=dave and the criteria property contains the property value. In this case Model Binding has worked but not when I use snake_case.

How can I use snake_case with Model Binding?

回答1:

You need to add [FromQuery] attribute to the model properties individually

public class Criteria
{
  [FromQuery(Name = "first_name")]
  public string FirstName { get; set; }
}

回答2:

Solution for .net core 2.1, 2.2 and 3.0

Or without attributes you can do something like this which is cleaner I think (of course if the model properties are same as query parameters).

Meanwhile I use it in .net core 2.1, 2.2 and 3.0 preview 5&6.

public async Task<IActionResult> Get([FromQuery]ReportQueryModel queryModel) 
{ 

}

回答3:

According to @Carl Thomas answer, here is the easier and the strognly typed way to have snake case FromQuery name:

CustomFromQuery

public class CustomFromQueryAttribute : FromQueryAttribute
{
    public CustomFromQuery(string name)
    {
        Name = name.ToSnakeCase();
    }
}

StringExtensions

public static class ObjectExtensions
{
  public static string ToSnakeCase(this string o) => Regex.Replace(o, @"(\w)([A-Z])", "$1_$2").ToLower();
}

Usage

public class Criteria
{
   [CustomFromQuery(nameof(FirstName))]
   public string FirstName { get; set; }
}

来源：https://stackoverflow.com/questions/42929376/bind-query-parameters-to-a-model-in-asp-net-core