我将如何创建绑定的int数组模型绑定？ [英] How would I create a model binder to bind an int array?

问题描述

我要创建我的ASP.NET MVC的Web API项目的GET端点其目的是采取一个整数数组在这样的网址：

I'm creating a GET endpoint in my ASP.NET MVC web API project which is intended to take a an integer array in the URL like this:

api.mything.com/stuff/2,3,4,5

这网址是由需要一个 INT [] 参数的操作服：

This URL is served by an action that takes an int[] parameter:

public string Get(int[] ids)

默认情况下，模型绑定不起作用 - IDS 只是空

所以，我创建了从逗号分隔的列表创建 INT [] 模型粘合剂。很简单。

So I created a model binder which creates an int[] from a comma-delimited list. Easy.

但我不能让模型绑定来触发。我创建了一个模型绑定提供者是这样的：

But I can't get the model binder to trigger. I created a model binder provider like this:

public override IModelBinder GetBinder(HttpConfiguration configuration, Type modelType)
{
  if (modelType == typeof(int[]))
  {
    return new IntArrayModelBinder();
  }

  return null;
}

它连接起来，所以我可以看到它执行在启动时，但仍然我的id参数仍然固执地空。

It's wired up so I can see it execute on startup but still my ids parameter remains stubbornly null.

我需要做什么呢？

推荐答案

以下是实现您的方案的一种方式：

Following is one way of achieving your scenario:

configuration.ParameterBindingRules.Insert(0, IntArrayParamBinding.GetCustomParameterBinding);
----------------------------------------------------------------------
public class IntArrayParamBinding : HttpParameterBinding
{
    private static Task completedTask = Task.FromResult(true);

    public IntArrayParamBinding(HttpParameterDescriptor desc)
        : base(desc)
    {
    }

    public override Task ExecuteBindingAsync(ModelMetadataProvider metadataProvider, HttpActionContext actionContext, CancellationToken cancellationToken)
    {
        HttpRouteData routeData = (HttpRouteData)actionContext.Request.GetRouteData();

        // note: here 'id' is the route variable name in my route template.
        int[] values = routeData.Values["id"].ToString().Split(new char[] { ',' }).Select(i => Convert.ToInt32(i)).ToArray();

        SetValue(actionContext, values);

        return completedTask;
    }

    public static HttpParameterBinding GetCustomParameterBinding(HttpParameterDescriptor descriptor)
    {
        if (descriptor.ParameterType == typeof(int[]))
        {
            return new IntArrayParamBinding(descriptor);
        }

        // any other types, let the default parameter binding handle
        return null;
    }

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

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