c# – dotnet核心webapi json-api兼容的查询字符串路由

我试图从请求的URL中获取“status”和“all”键值,并且无法弄清楚如何构建我的类对象.

我所指的JSON API规范可以在这里找到：
http://jsonapi.org/recommendations/#filtering

// requested url
/api/endpoint?filter[status]=all


// my attempt at model binding
public class FilterParams
{
    public Dictionary<string,string> Filter { get; set; }
}

[HttpGet]
public string Get([FromUri] FilterParams filter)
{
    // never gets populated...
    var filterStatus = filter.Filter["status"];
}

解决方法

>您可以使用 IModelBinder：

>定义模型绑定器：

public class FilterParamsModelBinder : IModelBinder
{
    public bool BindModel(HttpActionContext actionContext,ModelBindingContext bindingContext)
    {
        if (bindingContext.ModelType != typeof(FilterParams)) return false;

        Dictionary<string,string> result = new Dictionary<string,string>();

        var parameters = actionContext.Request.RequestUri.Query.Substring(1);

        if(parameters.Length == 0) return false;

        var regex = new Regex(@"filter\[(?<key>[\w]+)\]=(?<value>[\w^,]+)");

        parameters
            .Split('&')
            .ToList()
            .ForEach(_ =>
            {
                var groups = regex.Match(_).Groups;

                if(groups.Count == 0)
                    bindingContext.ModelState.AddModelError(bindingContext.ModelName,"Cannot convert value.");

                result.Add(groups["key"].Value,groups["value"].Value);
            });

        bindingContext.Model = new FilterParams { Filter = result};

        return bindingContext.ModelState.IsValid;
    }
}

>使用它：

[HttpGet]
public string Get([ModelBinderAttribute(typeof(FilterParamsModelBinder))] FilterParams filter)
{
  //your code
}

>如果您可以定义一个类似“/ api / endpoint？filter = status,all”的路由,那么您可以使用TypeConverter：

>定义转换器：

public class FilterConverter : TypeConverter
{
    public override object ConvertFrom(ITypeDescriptorContext context,CultureInfo culture,object value)
    {
        if (!(value is string)) return base.ConvertFrom(context,culture,value);

        var keyvalue = ((string)value).Split(',');

        return new FilterParams 
        {
            Filter = new Dictionary<string,string> { [keyvalue[0]] = keyvalue[1] } 
        };
    }

    public override bool CanConvertFrom(ITypeDescriptorContext context,Type sourceType) 
    {
       return sourceType == typeof(string) || base.CanConvertFrom(context,sourceType);
    }            
}

>使用它：

[TypeConverter(typeof(FilterConverter))]
public class FilterParams
{
    public Dictionary<string,string> Filter { get; set; }
}

[HttpGet]
public string Get(FilterParams filter)
{
    var filterStatus = filter.Filter["status"]; 
}