我有一个ASP。NET Web API(版本4)REST服务,我需要传递一个整数数组。

下面是我的动作方法:

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

这是我试过的网址:

/Categories?categoryids=1,2,3,4

当前回答

所有其他解决方案都需要大量的工作。我试图在HttpGet方法参数中使用IEnumerable<long>或long[],但我认为没有必要做所有的工作,只是为了使处理程序方法参数的签名long[]。我最终只是把它变成字符串,然后在处理程序中把它分开。我只说了一句。

public async Task<IActionResult> SomeHandler(string idsString)
{
    var ids = idsString.Split(',').Select(x => long.Parse(x));

现在你可以传递这些数字

.../SomeHandler?idsString=123,456,789,012

其他回答

我最初使用@Mrchief这个解决方案很多年了(它工作得很好)。但是当我将Swagger添加到我的API文档项目时,我的终点并没有显示出来。

这花了我一段时间,但这是我想到的。它与Swagger一起工作,你的API方法签名看起来更干净:

最后你可以做到:

    // GET: /api/values/1,2,3,4 

    [Route("api/values/{ids}")]
    public IHttpActionResult GetIds(int[] ids)
    {
        return Ok(ids);
    }

WebApiConfig.cs

public static class WebApiConfig
{
    public static void Register(HttpConfiguration config)
    {
        // Allow WebApi to Use a Custom Parameter Binding
        config.ParameterBindingRules.Add(descriptor => descriptor.ParameterType == typeof(int[]) && descriptor.ActionDescriptor.SupportedHttpMethods.Contains(HttpMethod.Get)
                                                           ? new CommaDelimitedArrayParameterBinder(descriptor)
                                                           : null);

        // Allow ApiExplorer to understand this type (Swagger uses ApiExplorer under the hood)
        TypeDescriptor.AddAttributes(typeof(int[]), new TypeConverterAttribute(typeof(StringToIntArrayConverter)));

        // Any existing Code ..

    }
}

创建一个新类:CommaDelimitedArrayParameterBinder.cs

public class CommaDelimitedArrayParameterBinder : HttpParameterBinding, IValueProviderParameterBinding
{
    public CommaDelimitedArrayParameterBinder(HttpParameterDescriptor desc)
        : base(desc)
    {
    }

    /// <summary>
    /// Handles Binding (Converts a comma delimited string into an array of integers)
    /// </summary>
    public override Task ExecuteBindingAsync(ModelMetadataProvider metadataProvider,
                                             HttpActionContext actionContext,
                                             CancellationToken cancellationToken)
    {
        var queryString = actionContext.ControllerContext.RouteData.Values[Descriptor.ParameterName] as string;

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

        SetValue(actionContext, ints);

        return Task.CompletedTask;
    }

    public IEnumerable<ValueProviderFactory> ValueProviderFactories { get; } = new[] { new QueryStringValueProviderFactory() };
}

创建一个新类:StringToIntArrayConverter.cs

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

注:

https://stackoverflow.com/a/47123965/862011为我指明了正确的方向 Swagger只是在使用[Route]属性时未能选择我的逗号分隔的端点

如果有人需要-通过POST而不是FromUri来实现相同或类似的事情(如删除),使用FromBody和客户端(JS/jQuery)格式参数为$。参数({":categoryids}, true)

c#:

public IHttpActionResult Remove([FromBody] int[] categoryIds)

jQuery:

$.ajax({
        type: 'POST',
        data: $.param({ '': categoryids }, true),
        url: url,
//...
});

关于$。Param ({": categoryids}, true)是。net期望post正文包含urlencoded的值,如=1&=2&=3,不带参数名,不带括号。

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。

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);
        }

我的解决方案是创建一个属性来验证字符串,它做了一堆额外的公共功能,包括regex验证,你可以使用它来检查数字,然后我根据需要转换为整数…

你可以这样使用:

public class MustBeListAndContainAttribute : ValidationAttribute
{
    private Regex regex = null;
    public bool RemoveDuplicates { get; }
    public string Separator { get; }
    public int MinimumItems { get; }
    public int MaximumItems { get; }

    public MustBeListAndContainAttribute(string regexEachItem,
        int minimumItems = 1,
        int maximumItems = 0,
        string separator = ",",
        bool removeDuplicates = false) : base()
    {
        this.MinimumItems = minimumItems;
        this.MaximumItems = maximumItems;
        this.Separator = separator;
        this.RemoveDuplicates = removeDuplicates;

        if (!string.IsNullOrEmpty(regexEachItem))
            regex = new Regex(regexEachItem, RegexOptions.Compiled | RegexOptions.Singleline | RegexOptions.IgnoreCase);
    }

    protected override ValidationResult IsValid(object value, ValidationContext validationContext)
    {
        var listOfdValues = (value as List<string>)?[0];

        if (string.IsNullOrWhiteSpace(listOfdValues))
        {
            if (MinimumItems > 0)
                return new ValidationResult(this.ErrorMessage);
            else
                return null;
        };

        var list = new List<string>();

        list.AddRange(listOfdValues.Split(new[] { Separator }, System.StringSplitOptions.RemoveEmptyEntries));

        if (RemoveDuplicates) list = list.Distinct().ToList();

        var prop = validationContext.ObjectType.GetProperty(validationContext.MemberName);
        prop.SetValue(validationContext.ObjectInstance, list);
        value = list;

        if (regex != null)
            if (list.Any(c => string.IsNullOrWhiteSpace(c) || !regex.IsMatch(c)))
                return new ValidationResult(this.ErrorMessage);

        return null;
    }
}