解析URL中的批量信息

1. 用Route形式承载批量信息：对于URL：api/touristRoutes/(1,2,3,4)这类括号内包含批量信息的情况
   通用的做法：①在http中匹配字符串：[HttpDelete("({Ids})")，此时Ids对应"1,2,3,4"，在类型时选择IEnumerable Ids，然后对Ids进行字符串解析

using Microsoft.AspNetCore.Mvc.ModelBinding;//Microsoft.AspNetCore.ModelBinding里面也有一个IModelBinder，注意区分  
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Reflection;
using System.Threading.Tasks;

namespace TouristTest.Helpers
{
    public class ArrayModelBinder : IModelBinder
    {
        public Task BindModelAsync(ModelBindingContext bindingContext)
        {
            // Our binder works only on enumerable types
            if (!bindingContext.ModelMetadata.IsEnumerableType)
            {
                bindingContext.Result = ModelBindingResult.Failed();
                return Task.CompletedTask;
            }

            // Get the inputted value through the value provider
            string value = bindingContext.ValueProvider.GetValue(bindingContext.ModelName).ToString();

            // If that value is null or whitespace, we return null
            if (string.IsNullOrWhiteSpace(value))
            {
                bindingContext.Result = ModelBindingResult.Success(null);
                return Task.CompletedTask;
            }

            // The value isn't null or whitespace, 
            // and the type of the model is enumerable. 
            // Get the enumerable's type, and a converter 
            Type elementType = bindingContext.ModelType.GetTypeInfo().GenericTypeArguments[0];
            TypeConverter converter = TypeDescriptor.GetConverter(elementType);

            // Convert each item in the value list to the enumerable type
            object[] values = value.Split(new[] { "," }, StringSplitOptions.RemoveEmptyEntries).Select(x => converter.ConvertFromString(x.Trim())).ToArray();

            // Create an array of that type, and set it as the Model value 
            Array typedValues = Array.CreateInstance(elementType, values.Length);
            values.CopyTo(typedValues, 0);
            bindingContext.Model = typedValues;

            // return a successful result, passing in the Model 
            bindingContext.Result = ModelBindingResult.Success(bindingContext.Model);
            return Task.CompletedTask;
        }
    }
}

使用

        [HttpDelete("({touristIDs})")]
        [Authorize(Roles = "Admin")]
        public async Task<IActionResult> DeleteByIDs(
            [ModelBinder( BinderType = typeof(ArrayModelBinder))][FromRoute]IEnumerable<Guid> touristIDs)
        {
            if(touristIDs == null)
            {
                return BadRequest();
            }

            var touristRoutesFromRepo = await _touristRouteRepository.GetTouristRoutesByIDListAsync(touristIDs);
            _touristRouteRepository.DeleteTouristRoutes(touristRoutesFromRepo);
            await _touristRouteRepository.SaveAsync();

            return NoContent();
        }

2. 用FromQuery的形式承载批量信息：对于URL：api/touristRoutes?Ids=1,2,3,4&orderby=title desc,description
   api/touristRoutes?orderby=title,id这种一个词携带多个的情况：
   1、单个变量直接使用

[route("search")]
public IActionResult Action([FromQuery(Name="actions")] string keyword,[FromQuery(Name="actions2")] string keyword2){}
//传入的URL：https:localhost/api/search?actions=123&actions2=234

//或者
[route("search")]
public IActionResult Action([FromQuery] string keyword,string keyword2){}//两者都是FromQuery，写一个或者都不写。
//传入的URL应为：https:localhost/api/search?keyword=123&keyword2=234

2、将全部的变量单独封装
new一个新的类，封装全部的关键词，并在该类中把URL信息中包含的逻辑信息解析为参数。
例：URL信息为：https:localhost/api/search?actions=lessthan123&actions2=234(包含的信息为小于123)
下面为类的代码：

    public class TouristRouteResourceParamaters
    {
        public string Keyword { get; set; }//不包含逻辑的直接get set一个属性
        public string RatingOperator { get; set; }
        public int? RatingValue { get; set; }
        private string _rating;//包含逻辑的需要写一个逻辑，把rating转化为Rating、RatingValue、RatingOperator
        public string Rating {
            get { return _rating; }
            set 
            {
                if (!string.IsNullOrWhiteSpace(value))
                {
                    Regex regex = new Regex(@"([A-Za-z0-9\-]+)(\d+)");
                    Match match = regex.Match(value);
                    if (match.Success)
                    {
                        RatingOperator = match.Groups[1].Value;
                        RatingValue = Int32.Parse(match.Groups[2].Value);
                    }
                }
                _rating = value;
            } 
        }
    }

使用方法：
public async Task<IActionResult> GerTouristRoutes([FromQuery] TouristRouteResourceParamaters paramaters)
调用参数(例）

           if (!_propertyMappingService
                .IsMappingExists<TouristRouteDto, TouristRoute>(
                paramaters.OrderBy))
            {
                return BadRequest("请输入正确的排序参数");
            }