如何从具有特定属性的对象的 C# 列表中创建 json 字符串？

Question

考虑到我在下拉列表中有以下值（dropDownList 变量）并且用户选择的值在 selectedDropDownValues 列表中。

和 DB api returns 客户列表（customerDBList 变量）。

现在的要求是根据下面提到的选定值构建 JSON -

var dropDownList = new[] { "Customer.Id", "Customer.FirstName", "Customer.LastName", "Customer.Address.AddressLine1", "Customer.Address.AddressLine2" };

var selectedDropDownValues = new[] { "Customer.Id", "Customer.FirstName", "Customer.Address.AddressLine1" };

var customerDBList = new List<Customer>(){
                new Customer {
                    Id=1,
                    FirstName="John",
                    LastName="Desouza",
                    Address=new Address{            
                                AddressLine1="1 Street",
                                AddressLine2="Linking Road"
                    }},        
                new Customer {
                    Id=2,
                    FirstName="Sam",
                    LastName="Lewis",
                    Address=new Address{            
                                AddressLine1="Fedral Highway",
                                AddressLine2="Louisville"
                    }                
                }};

预期 JSON 输出为 -

[
  {
    "Customer": {
      "Id": 1,
      "FirstName": "John",
      "Address": {
        "AddressLine1": "1 Street"
      }
    }
  },
  {
    "Customer": {
      "Id": 2,
      "FirstName": "Sam",
      "Address": {
        "AddressLine1": "Fedral Highway"
      }
    }
  }
]

Answer 1

碰巧，您的 selectedDropDownValues 字符串 "Customer.Address.AddressLine1" 在 JSONPath syntax, so you could convert your Customer objects to an intermediate JObject then prune unwanted values using JsonExtensions.RemoveAllExcept(this JObject obj, IEnumerable<string> paths) from to .

请注意，您想要的 JSON 有一个额外的嵌套级别 { "Customer": { ... } } 在您的数据模型中不存在，因此需要在过滤之前手动插入：

var rootName = "Customer";

var query = customerDBList
    // Convert to JObject
    .Select(c => JObject.FromObject(c))
    // Add additional level of object nesting { "Customer": { ... } } 
    .Select(o => new JObject( new JProperty(rootName, o)))
    // Remove all but selected properties.
    .Select(o => o.RemoveAllExcept(selectedDropDownValues));

var json = JsonConvert.SerializeObject(query, Formatting.Indented);

工作示例 .Net fiddle here 根据需要显示生成的 JSON

[
  {
    "Customer": {
      "Id": 1,
      "FirstName": "John",
      "Address": {
        "AddressLine1": "1 Street"
      }
    }
  },
  {
    "Customer": {
      "Id": 2,
      "FirstName": "Sam",
      "Address": {
        "AddressLine1": "Fedral Highway"
      }
    }
  }
]

如何从具有特定属性的对象的 C# 列表中创建 json 字符串？

How to create json string from C# list of object with specific properties?

c#

json

list

c#-3.0