我已经创建了一个自定义模型绑定器，它将任何逗号分隔的值(仅为原语、十进制、浮点数、字符串)转换为相应的数组。

public class CommaSeparatedToArrayBinder<T> : IModelBinder
    {
        public bool BindModel(HttpActionContext actionContext, ModelBindingContext bindingContext)
        {
            Type type = typeof(T);
            if (type.IsPrimitive || type == typeof(Decimal) || type == typeof(String) || type == typeof(float))
            {
                ValueProviderResult val = bindingContext.ValueProvider.GetValue(bindingContext.ModelName);
                if (val == null) return false;

                string key = val.RawValue as string;
                if (key == null) { bindingContext.ModelState.AddModelError(bindingContext.ModelName, "Wrong value type"); return false; }

                string[] values = key.Split(',');
                IEnumerable<T> result = this.ConvertToDesiredList(values).ToArray();
                bindingContext.Model = result;
                return true;
            }

            bindingContext.ModelState.AddModelError(bindingContext.ModelName, "Only primitive, decimal, string and float data types are allowed...");
            return false;
        }

        private IEnumerable<T> ConvertToDesiredArray(string[] values)
        {
            foreach (string value in values)
            {
                var val = (T)Convert.ChangeType(value, typeof(T));
                yield return val;
            }
        }
    }

以及如何在Controller中使用:

 public IHttpActionResult Get([ModelBinder(BinderType = typeof(CommaSeparatedToArrayBinder<int>))] int[] ids)
        {
            return Ok(ids);
        }

ASP。NET Core 2.0解决方案(Swagger Ready)

输入

DELETE /api/items/1,2
DELETE /api/items/1

Code

编写提供程序(MVC如何知道使用什么绑定器)

public class CustomBinderProvider : IModelBinderProvider
{
    public IModelBinder GetBinder(ModelBinderProviderContext context)
    {
        if (context == null)
        {
            throw new ArgumentNullException(nameof(context));
        }

        if (context.Metadata.ModelType == typeof(int[]) || context.Metadata.ModelType == typeof(List<int>))
        {
            return new BinderTypeModelBinder(typeof(CommaDelimitedArrayParameterBinder));
        }

        return null;
    }
}

编写实际的绑定器(访问关于请求、操作、模型、类型等的各种信息)

public class CommaDelimitedArrayParameterBinder : IModelBinder
{

    public Task BindModelAsync(ModelBindingContext bindingContext)
    {

        var value = bindingContext.ActionContext.RouteData.Values[bindingContext.FieldName] as string;

        // Check if the argument value is null or empty
        if (string.IsNullOrEmpty(value))
        {
            return Task.CompletedTask;
        }

        var ints = value?.Split(',').Select(int.Parse).ToArray();

        bindingContext.Result = ModelBindingResult.Success(ints);

        if(bindingContext.ModelType == typeof(List<int>))
        {
            bindingContext.Result = ModelBindingResult.Success(ints.ToList());
        }

        return Task.CompletedTask;
    }
}

将它注册到MVC

services.AddMvc(options =>
{
    // add custom binder to beginning of collection
    options.ModelBinderProviders.Insert(0, new CustomBinderProvider());
});

示例使用与Swagger良好记录的控制器

/// <summary>
/// Deletes a list of items.
/// </summary>
/// <param name="itemIds">The list of unique identifiers for the  items.</param>
/// <returns>The deleted item.</returns>
/// <response code="201">The item was successfully deleted.</response>
/// <response code="400">The item is invalid.</response>
[HttpDelete("{itemIds}", Name = ItemControllerRoute.DeleteItems)]
[ProducesResponseType(typeof(void), StatusCodes.Status204NoContent)]
[ProducesResponseType(typeof(void), StatusCodes.Status404NotFound)]
public async Task Delete(List<int> itemIds)
=> await _itemAppService.RemoveRangeAsync(itemIds);

编辑:微软建议使用TypeConverter来代替这种方法。因此，按照下面海报的建议，用SchemaFilter记录您的自定义类型。

除了使用自定义ModelBinder，还可以使用带有TypeConverter的自定义类型。

[TypeConverter(typeof(StrListConverter))]
public class StrList : List<string>
{
    public StrList(IEnumerable<string> collection) : base(collection) {}
}

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

    public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value)
    {
        if (value == null)
            return null;

        if (value is string s)
        {
            if (string.IsNullOrEmpty(s))
                return null;
            return new StrList(s.Split(','));
        }
        return base.ConvertFrom(context, culture, value);
    }
}

它的优点是使Web API方法的参数非常简单。你甚至不需要指定[FromUri]。

public IEnumerable<Category> GetCategories(StrList categoryIds) {
  // code to retrieve categories from database
}

这个例子是一个字符串列表，但你可以使用categoryIds.Select(int.Parse)或简单地编写一个IntList代替。

我最近遇到了这个需求，我决定实现一个ActionFilter来处理这个问题。

public class ArrayInputAttribute : ActionFilterAttribute
{
    private readonly string _parameterName;

    public ArrayInputAttribute(string parameterName)
    {
        _parameterName = parameterName;
        Separator = ',';
    }

    public override void OnActionExecuting(HttpActionContext actionContext)
    {
        if (actionContext.ActionArguments.ContainsKey(_parameterName))
        {
            string parameters = string.Empty;
            if (actionContext.ControllerContext.RouteData.Values.ContainsKey(_parameterName))
                parameters = (string) actionContext.ControllerContext.RouteData.Values[_parameterName];
            else if (actionContext.ControllerContext.Request.RequestUri.ParseQueryString()[_parameterName] != null)
                parameters = actionContext.ControllerContext.Request.RequestUri.ParseQueryString()[_parameterName];

            actionContext.ActionArguments[_parameterName] = parameters.Split(Separator).Select(int.Parse).ToArray();
        }
    }

    public char Separator { get; set; }
}

我像这样应用它(注意，我使用'id'，而不是'ids'，因为这是如何在我的路由中指定的):

[ArrayInput("id", Separator = ';')]
public IEnumerable<Measure> Get(int[] id)
{
    return id.Select(i => GetData(i));
}

public url是:

/api/Data/1;2;3;4

您可能必须对其进行重构以满足您的特定需求。

正如Filip W指出的那样，你可能不得不求助于这样的自定义模型绑定器(修改为绑定到实际的参数类型):

public IEnumerable<Category> GetCategories([ModelBinder(typeof(CommaDelimitedArrayModelBinder))]long[] categoryIds) 
{
    // do your thing
}

public class CommaDelimitedArrayModelBinder : IModelBinder
{
    public bool BindModel(HttpActionContext actionContext, ModelBindingContext bindingContext)
    {
        var key = bindingContext.ModelName;
        var val = bindingContext.ValueProvider.GetValue(key);
        if (val != null)
        {
            var s = val.AttemptedValue;
            if (s != null)
            {
                var elementType = bindingContext.ModelType.GetElementType();
                var converter = TypeDescriptor.GetConverter(elementType);
                var values = Array.ConvertAll(s.Split(new[] { ","},StringSplitOptions.RemoveEmptyEntries),
                    x => { return converter.ConvertFromString(x != null ? x.Trim() : x); });

                var typedValues = Array.CreateInstance(elementType, values.Length);

                values.CopyTo(typedValues, 0);

                bindingContext.Model = typedValues;
            }
            else
            {
                // change this line to null if you prefer nulls to empty arrays 
                bindingContext.Model = Array.CreateInstance(bindingContext.ModelType.GetElementType(), 0);
            }
            return true;
        }
        return false;
    }
}

然后你可以说:

/类别?categoryids=1,2,3,4和ASP。NET Web API将正确绑定您的categoryIds数组。

你只需要在参数前添加[FromUri]，看起来像:

GetCategories([FromUri] int[] categoryIds)

并发送请求:

/Categories?categoryids=1&categoryids=2&categoryids=3