我们假设你有以下代码
public class MyClass {
public double Latitude {get; set;}
public double Longitude {get; set;}
}
public class Criteria
{
public DateTime StartDate { get; set; }
public DateTime EndDate { get; set; }
public MyClass MyProp {get; set;}
}
[HttpGet]
public Criteria Get([FromUri] Criteria c)
{
return c;
}
我想知道是否有人知道可以将任何对象转换为WEB API 2控制器可以理解的查询字符串的库。
这是我喜欢的一个例子
SerializeToQueryString(new Criteria{StartDate=DateTime.Today, EndDate = DateTime.Today.AddDays(1), MyProp = new MyProp{Latitude=1, Longitude=3}});
=> "startDate=2015-10-13&endDate=2015-10-14&myProp.latitude=1&myProp.longitude=3"
httpClient的完整示例可能如下所示：
new HttpClient("http://localhost").GetAsync("/tmp?"+SerializeToQueryString(new Criteria{StartDate=DateTime.Today, EndDate = DateTime.Today.AddDays(1), MyProp = new MyProp{Latitude=1, Longitude=3}})).Result;
目前，我使用的是一个版本（取自我再也找不到的问题，也许是How do I serialize an object into query-string format? ...）。
问题在于除了简单的属性之外，它不能用于其他任何事情。 例如，在Date上调用ToString将不会提供WEB API 2控制器可解析的内容......
private string SerializeToQueryString<T>(T aObject)
{
var query = HttpUtility.ParseQueryString(string.Empty);
var fields = typeof(T).GetProperties();
foreach (var field in fields)
{
string key = field.Name;
var value = field.GetValue(aObject);
if (value != null)
query[key] = value.ToString();
}
return query.ToString();
}
答案 0 :(得分：2)
＆＃34;将任何对象转换为查询字符串＆＃34;似乎暗示这是一种标准格式，而且根本就没有。所以你需要选择一个或自己动手。由于可用的库很好，JSON似乎是显而易见的选择。
答案 1 :(得分：0)
由于以前似乎没有人处理过这个问题，这里是我在项目中使用的解决方案：
using System;
using System.Collections;
using System.Collections.Specialized;
using System.Globalization;
using System.Linq;
using System.Web;
namespace App
{
public class QueryStringSerializer
{
public static string SerializeToQueryString(object aObject)
{
return SerializeToQueryString(aObject, "").ToString();
}
private static NameValueCollection SerializeToQueryString(object aObject, string prefix)
{
//!\ doing this to get back a HttpValueCollection which is an internal class
//we want a HttpValueCollection because toString on this class is what we want in the public method
//cf http://stackoverflow.com/a/17096289/1545567
var query = HttpUtility.ParseQueryString(String.Empty);
var fields = aObject.GetType().GetProperties();
foreach (var field in fields)
{
string key = string.IsNullOrEmpty(prefix) ? field.Name : prefix + "." + field.Name;
var value = field.GetValue(aObject);
if (value != null)
{
var propertyType = GetUnderlyingPropertyType(field.PropertyType);
if (IsSupportedType(propertyType))
{
query.Add(key, ToString(value));
}
else if (value is IEnumerable)
{
var enumerableValue = (IEnumerable) value;
foreach (var enumerableValueElement in enumerableValue)
{
if (IsSupportedType(GetUnderlyingPropertyType(enumerableValueElement.GetType())))
{
query.Add(key, ToString(enumerableValueElement));
}
else
{
//it seems that WEB API 2 Controllers are unable to deserialize collections of complex objects...
throw new Exception("can not use IEnumerable<T> where T is a class because it is not understood server side");
}
}
}
else
{
var subquery = SerializeToQueryString(value, key);
query.Add(subquery);
}
}
}
return query;
}
private static Type GetUnderlyingPropertyType(Type propType)
{
var nullablePropertyType = Nullable.GetUnderlyingType(propType);
return nullablePropertyType ?? propType;
}
private static bool IsSupportedType(Type propertyType)
{
return SUPPORTED_TYPES.Contains(propertyType) || propertyType.IsEnum;
}
private static readonly Type[] SUPPORTED_TYPES = new[]
{
typeof(DateTime),
typeof(string),
typeof(int),
typeof(long),
typeof(float),
typeof(double)
};
private static string ToString(object value)
{
if (value is DateTime)
{
var dateValue = (DateTime) value;
if (dateValue.Hour == 0 && dateValue.Minute == 0 && dateValue.Second == 0)
{
return dateValue.ToString("yyyy-MM-dd");
}
else
{
return dateValue.ToString("yyyy-MM-dd HH:mm:ss");
}
}
else if (value is float)
{
return ((float) value).ToString(CultureInfo.InvariantCulture);
}
else if (value is double)
{
return ((double)value).ToString(CultureInfo.InvariantCulture);
}
else /*int, long, string, ENUM*/
{
return value.ToString();
}
}
}
}
以下是演示的单元测试：
using System;
using System.Collections.Generic;
using System.Globalization;
using Microsoft.VisualStudio.TestTools.UnitTesting;
namespace Framework.WebApi.Core.Tests
{
[TestClass]
public class QueryStringSerializerTest
{
public class EasyObject
{
public string MyString { get; set; }
public int? MyInt { get; set; }
public long? MyLong { get; set; }
public float? MyFloat { get; set; }
public double? MyDouble { get; set; }
}
[TestMethod]
public void TestEasyObject()
{
var queryString = QueryStringSerializer.SerializeToQueryString(new EasyObject(){MyString = "string", MyInt = 1, MyLong = 1L, MyFloat = 1.5F, MyDouble = 1.4});
Assert.IsTrue(queryString.Contains("MyString=string"));
Assert.IsTrue(queryString.Contains("MyInt=1"));
Assert.IsTrue(queryString.Contains("MyLong=1"));
Assert.IsTrue(queryString.Contains("MyFloat=1.5"));
Assert.IsTrue(queryString.Contains("MyDouble=1.4"));
}
[TestMethod]
public void TestEasyObjectNullable()
{
var queryString = QueryStringSerializer.SerializeToQueryString(new EasyObject() { });
Assert.IsTrue(queryString == "");
}
[TestMethod]
public void TestUrlEncoding()
{
var queryString = QueryStringSerializer.SerializeToQueryString(new EasyObject() { MyString = "&=/;+" });
Assert.IsTrue(queryString.Contains("MyString=%26%3d%2f%3b%2b"));
}
public class DateObject
{
public DateTime MyDate { get; set; }
}
[TestMethod]
public void TestDate()
{
var d = DateTime.ParseExact("2010-10-13", "yyyy-MM-dd", CultureInfo.InvariantCulture);
var queryString = QueryStringSerializer.SerializeToQueryString(new DateObject() { MyDate = d });
Assert.IsTrue(queryString.Contains("MyDate=2010-10-13"));
}
[TestMethod]
public void TestDateTime()
{
var d = DateTime.ParseExact("2010-10-13 20:00", "yyyy-MM-dd HH:mm", CultureInfo.InvariantCulture);
var queryString = QueryStringSerializer.SerializeToQueryString(new DateObject() { MyDate = d });
Assert.IsTrue(queryString.Contains("MyDate=2010-10-13+20%3a00%3a00"));
}
public class InnerComplexObject
{
public double Lat { get; set; }
public double Lon { get; set; }
}
public class ComplexObject
{
public InnerComplexObject Inner { get; set; }
}
[TestMethod]
public void TestComplexObject()
{
var queryString = QueryStringSerializer.SerializeToQueryString(new ComplexObject() { Inner = new InnerComplexObject() {Lat = 50, Lon = 2} });
Assert.IsTrue(queryString.Contains("Inner.Lat=50"));
Assert.IsTrue(queryString.Contains("Inner.Lon=2"));
}
public class EnumerableObject
{
public IEnumerable<int> InnerInts { get; set; }
}
[TestMethod]
public void TestEnumerableObject()
{
var queryString = QueryStringSerializer.SerializeToQueryString(new EnumerableObject() {
InnerInts = new[] { 1,2 }
});
Assert.IsTrue(queryString.Contains("InnerInts=1"));
Assert.IsTrue(queryString.Contains("InnerInts=2"));
}
public class ComplexEnumerableObject
{
public IEnumerable<InnerComplexObject> Inners { get; set; }
}
[TestMethod]
public void TestComplexEnumerableObject()
{
try
{
QueryStringSerializer.SerializeToQueryString(new ComplexEnumerableObject()
{
Inners = new[]
{
new InnerComplexObject() {Lat = 50, Lon = 2},
new InnerComplexObject() {Lat = 51, Lon = 3},
}
});
Assert.Fail("we should refuse something that will not be understand by the server");
}
catch (Exception e)
{
Assert.AreEqual("can not use IEnumerable<T> where T is a class because it is not understood server side", e.Message);
}
}
public enum TheEnum : int
{
One = 1,
Two = 2
}
public class EnumObject
{
public TheEnum? MyEnum { get; set; }
}
[TestMethod]
public void TestEnum()
{
var queryString = QueryStringSerializer.SerializeToQueryString(new EnumObject() { MyEnum = TheEnum.Two});
Assert.IsTrue(queryString.Contains("MyEnum=Two"));
}
}
}
我要感谢所有参与者，即使这不是您通常应该以Q＆amp; A格式进行的事情：）