我如何遍历这个 JObject？

Question

我能够读取 json 文件并将其存储在 JObject 变量中。我需要检查空值并忽略任何具有空值的段。我正在考虑遍历 JObject，但我不知道如何访问下面 json 中的每个段/键。

我想我们可以根据我在这里看到的另一个问题像这样循环：

 foreach (var x in example) //example is the JObject in which json file is stored
    {
        string name = x.Key;
        JToken value = x.Value;

    }

但是我的json没有钥匙。我如何进入每个段并检查名称、描述值是否不为空？

我的 json 是：

{
  "lorem ipsum Segment Groups":[
    {
      "name":"lorem ipsum",
      "description":"lorem ipsum",
      "segments":[
        "Not Enrolled",
        "Started Enrollment – Zipcode Lookup",
        "Started Enrollment – Passed Flow Step 1",
        "Started Enrollment – Passed Flow Step 2"
      ]
    },
    {
      "name":"lorem ipsum",
      "description":"Status Description",
      "segments":[
        "Moving in next 30 days",
        "Moving in next 90 days",
        "Not Moving"
      ]
    },
    {
      "name":"lorem ipsum",
      "description":"Interest description",
      "segments":[
        "Interested - Lots of Time Reading Many Pages",
        "Interested - Lots of Time Comparing Products/Prices"
      ]
    }
  ]
}

谢谢

Answer 1

这是一个如何循环遍历 JSON 的示例：

JObject obj = JObject.Parse(json);

JArray segmentGroups = (JArray)obj.Properties().FirstOrDefault()?.Value; 
if (segmentGroups != null)
{
    foreach (JObject group in segmentGroups.Children<JObject>())
    {
        string name = (string)group["name"];
        string desc = (string)group["description"];
        string[] segments = group["segments"]?.ToObject<string[]>();
        
        Console.WriteLine("name: " + (name ?? "(null)"));
        Console.WriteLine("description: " + (desc ?? "(null)"));
        Console.WriteLine("segments: " + (segments != null ? "\n  " + string.Join("\n  ", segments) : "(null)"));
        Console.WriteLine();
    }
}

Fiddle: https://dotnetfiddle.net/kOJzaZ

Answer 2

通过了解JSON结构，您可以使用名称格式为JXxx的各种类型来读取您想要的值。但是这里有一种方便的方法可以使用 json path 选择您想要的标记。这样您就可以方便地定位所需的令牌集并继续处理。我不太确定这种方法对性能的影响，但您可以权衡取舍（如果性能确实重要，请先尝试对其进行基准测试）。

代码可以这么简单：

//suppose your example is the loaded JObject
foreach (var group in example.SelectTokens("['lorem ipsum Segment Groups'][*]"))
{
    var name = group["name"].Value<string>();
    var desc = group["description"].Value<string>();
    //check if they are null here ...

}

请注意我们通过将包含空格的键或路径包裹在 [''] 中来转义它的方式。如果你的密钥不需要转义，直接在路径中使用即可。

我如何遍历这个 JObject？

How do I loop over this JObject?

c#

json

json.net

.net-core

asp.net-core