c# - JToken 不包含“长度”的定义

Question

我在扩展名为 .json 的文件中有一个 JSON 数据。我从文件中抓取并读取 JSON。我的问题是如何检查 payment 数组是否有子数组。

我试过 o2["payment"].length() 但它给我一个错误

'JToken' does not contain a definition for 'length' and no extension method 'length' accepting a first argument of type 'JToken' could be found (are you missing a using directive or an assembly reference?)

我正在使用 Json.NET

{
    "bank_name": "MyBank",
    "payment": [
        {
            "ssn": "123456789",
            "description": "Payment for income tax for 2015",
            "amount": "55.00"
        },
        {
            "ssn": "123456789",
            "description": "Payment for income tax for 2016",
            "amount": "95.10"
        },
        {
            "ssn": "123456789",
            "description": "Payment for income tax for 2017",
            "amount": "35.03"
        }
    ]
}




public ActionResult ReadFile()
{

    var Path = "C:\\Payment";
    var PendingPath = Path + "\\Pending";

    string[] FilePaths = Directory.GetFiles(@PendingPath, "*.json");
    foreach ( var CurrentFile in FilePaths )
    {
        using (StreamReader file = System.IO.File.OpenText(CurrentFile))
        using (JsonTextReader reader = new JsonTextReader(file))
        {
            JObject o2 = (JObject)JToken.ReadFrom(reader);
            var bank_name = o2["bank_name"];
            if ( o2["payment"].length() ) //Check here if payment has any children
            {

            }
        }
    }

    return new EmptyResult();
}

Answer 1

如果你想使用数组的方法，你应该转换对象:

if (((JArray)o2["payment"]).Count > 0)
{
    // Logic...
}