Question

我正在尝试从请求的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"];
}

Answer 1

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
}

如果您可以定义类似＆＃34; / api / endpoint？filter = status的路线，那么＆＃34;相反，你可以使用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"]; 
}

Answer 2

如果您要在.Net Core上构建json：api应用，我强烈建议您检出以下库：https://github.com/json-api-dotnet/JsonApiDotNetCore

它为您处理了所有繁重的工作，对于此特定示例，（需要获取过滤器值），解决方案如下：

ggplot(data.frame(x = c(-2, 2)), aes((x),xname ='wind') ) +
    stat_function(fun = dnorm, args = list(mean = -0.05116279, sd = 0.5725349),                                                  aes(colour = "1 hour"))  +xlab("wind_speed_Error",cex.lab=1.5, cex.axis=1.5) +
    stat_function(fun=dnorm, args = list(mean = -0.355, sd = 0.6602059),  aes(colour = "4 hour"))  +
    scale_colour_manual("Predictions",values=c("blue","red"))

dotnet核心webapi json-api兼容查询字符串路由

2 个答案: