如何在Web API 2中强制执行必需的查询字符串参数？

Question

给定使用[FromUri]的示例：

public class GeoPoint
{
    public double Latitude { get; set; } 
    public double Longitude { get; set; }
}

public ValuesController : ApiController
{
    public HttpResponseMessage Get([FromUri] GeoPoint location) { ... }
}

http://localhost/api/values/和http://localhost/api/values/?Latitude=47.678558&Longitude=-122.130989都将在当前实现中将Latitude和Longitude都设置为0，但是我想区分两者因此，如果未提供这些错误，则会抛出400错误。

如果未提供“ Latitude或“ Longitude是否可以拒绝请求？

Answer 1

您可以重载此操作：

[HttpGet]
    public HttpResponseMessage Get([FromUri] GeoPoint location) { ... }

[HttpGet]
public HttpResponseMessage Get() { 
    throw new Exception("404'd");
    ...
 }

或者，您可以使您的类成员可以为空，并进行空检查：

public class GeoPoint
{
    public double? Latitude { get; set; } 
    public double? Longitude { get; set; }
}

    public ValuesController : ApiController
    {
        public HttpResponseMessage Get([FromUri] GeoPoint location) 
        { 
             if(location == null || location.Longitude == null || location.Latitude == null)
                throw new Exception("404'd");
        }
    }

Answer 2

我这样做了，最终看起来像@mambrow的第二个选项，只是其余的代码不必处理可空类型：

public class GeoPoint
{
    private double? _latitude;
    private double? _longitude;

    public double Latitude {
        get { return _latitude ?? 0; }
        set { _latitude = value; }
    }

    public double Longitude { 
        get { return _longitude ?? 0; }
        set { _longitude = value; }
    }

    public bool IsValid()
    {
        return ( _latitude != null && _longitude != null )
}

public ValuesController : ApiController
{
    public HttpResponseMessage Get([FromUri] GeoPoint location)
    {
        if ( !location.IsValid() ) { throw ... }
        ...
    }
}