c# - 如果要删除某些元素，如何迭代 JObject？

Question

摘要:

通过美国教育部 API，我计划创建一份大学列表及其计算机科学毕业生的中位工资。但是，许多学校都有空值，尝试删除空值会破坏代码，因为在枚举集合时无法修改集合。

我的取消器代码:

static JObject DeNullifier(JObject inputJson)
{
    //Each school in the results[] section
    foreach(var school in inputJson["results"])
    {
        //Each degree in the cip_4_digit section
        foreach(var degree in school["latest.programs.cip_4_digit"])
        {
            if(string.IsNullOrEmpty(degree["earnings.median_earnings"].Value<string>()))
            {
                degree.Remove();
            }
        }
    }
    return inputJson;
}

JSON 缩短版本:

{
    "metadata": 
    {
        "total": 1444,
        "page": 14,
        "per_page": 100
    },

    "results": 
    [
        {
            "school.name": "Georgia College & State University",
            "latest.programs.cip_4_digit": 
            [
                {
                  "earnings.median_earnings": 53200,
                  "title": "Computer Science.",
                  "code": "1107"
                }
            ]
        },
        {
            "school.name": "Georgia Southern University",
            "latest.programs.cip_4_digit": 
            [
                {
                  "earnings.median_earnings": null,
                  "title": "Computer Science.",
                  "code": "1107"
                }
            ]
        }
    ]
}

Newtonsoft JSON.NET 类引用:

https://www.newtonsoft.com/json/help/html/Methods_T_Newtonsoft_Json_Linq_JObject.htm

https://www.newtonsoft.com/json/help/html/T_Newtonsoft_Json_Linq_JToken.htm

https://www.newtonsoft.com/json/help/html/T_Newtonsoft_Json_Linq_JProperty.htm

Answer 1

您可以将要删除的节点添加到不同的集合中，然后将其删除。例如，

static JObject DeNullifier(JObject inputJson)
{
    var nodesToRemove = new List<JToken>();
    //Each school in the results[] section
    foreach(var school in inputJson["results"])
    {
        //Each degree in the cip_4_digit section
        foreach(var degree in school["latest.programs.cip_4_digit"])
        {
            if(string.IsNullOrEmpty(degree["earnings.median_earnings"].Value<string>()))
            {
                nodesToRemove.Add(degree);
            }
        }
    }

    foreach(var node in nodesToRemove)
    {
        node.Remove();
    }
    return inputJson;
}