如何使用Web API中的属性路由通过URI发送数组？ [英] How to send an array via a URI using Attribute Routing in Web API?

问题描述

我正在关注有关Web API 2中属性路由的文章，尝试通过URI发送数组：

I'm following the article on Attribute Routing in Web API 2 to try to send an array via URI:

[HttpPost("api/set/copy/{ids}")]
public HttpResponseMessage CopySet([FromUri]int[] ids)

这在使用基于约定的路由时有效：

This was working when using convention-based routing:

http://localhost:24144/api/set/copy/?ids=1&ids=2&ids=3

但是使用属性路由，它不再起作用-我找不到404。

But with attribute routing it is no longer working - I get 404 not found.

如果我尝试这样做：

http://localhost:24144/api/set/copy/1

然后它起作用了-我得到一个包含一个元素的数组。

Then it works - I get an array with one element.

如何以这种方式使用属性路由？

How do I use attribute routing in this manner?

推荐答案

您注意到的行为与动作选择和模型绑定而不是属性路由。

The behavior you are noticing is more related to Action selection & Model binding rather than Attribute Routing.

如果您希望 ids来自查询字符串，请按如下所示修改路由模板（因为定义方式）使'ids在uri路径中成为必需项）：

If you are expecting 'ids' to come from query string, then modify your route template like below(because the way you have defined it makes 'ids' mandatory in the uri path):

[HttpPost("api/set/copy")]

看看第二个问题，您是否想接受uri本身的ID列表，例如 api / set / copy / [1,2,3] ？如果是，我认为Web api不对这种模型绑定提供内置支持。

Looking at your second question, are you looking to accept a list of ids within the uri itself, like api/set/copy/[1,2,3]? if yes, I do not think web api has in-built support for this kind of model binding.

您可以实现如下所示的自定义参数绑定来实现此目的（我想还有其他更好的方法，例如通过modelbinders和值提供者来实现这一点，但我是不太了解它们...所以您可能也需要探索这些选项）：

You could implement a custom parameter binding like below to achieve it though(I am guessing there are other better ways to achieve this like via modelbinders and value providers, but i am not much aware of them...so you could probably need to explore those options too):

[HttpPost("api/set/copy/{ids}")]
public HttpResponseMessage CopySet([CustomParamBinding]int[] ids)

---

示例：

---

Example:

[AttributeUsage(AttributeTargets.Parameter, Inherited = false, AllowMultiple = false)]
public class CustomParamBindingAttribute : ParameterBindingAttribute
{
    public override HttpParameterBinding GetBinding(HttpParameterDescriptor paramDesc)
    {
        return new CustomParamBinding(paramDesc);
    }
}

public class CustomParamBinding : HttpParameterBinding
{
    public CustomParamBinding(HttpParameterDescriptor paramDesc) : base(paramDesc) { }

    public override bool WillReadBody
    {
        get
        {
            return false;
        }
    }

    public override Task ExecuteBindingAsync(ModelMetadataProvider metadataProvider, HttpActionContext actionContext, 
                                                    CancellationToken cancellationToken)
    {
        //TODO: VALIDATION & ERROR CHECKS
        string idsAsString = actionContext.Request.GetRouteData().Values["ids"].ToString();

        idsAsString = idsAsString.Trim('[', ']');

        IEnumerable<string> ids = idsAsString.Split(',');
        ids = ids.Where(str => !string.IsNullOrEmpty(str));

        IEnumerable<int> idList = ids.Select(strId =>
            {
                if (string.IsNullOrEmpty(strId)) return -1;

                return Convert.ToInt32(strId);

            }).ToArray();

        SetValue(actionContext, idList);

        TaskCompletionSource<object> tcs = new TaskCompletionSource<object>();
        tcs.SetResult(null);
        return tcs.Task;
    }
}

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