Question

我是JSON的新手，无法解决以下问题：

我正在从第三方程序获取JSON文件。 JSON如下所示：

{
"Name 1": {
    "Property 1": 154600,
    "Property 2": true,
    "Property 3": 5340,
    "Property 4": 54634
  },
  "Name 2": {
    "Property 1": 5436,
    "Property 2": false,
    "Property 3": 45678769,
    "Property 4": 2342342
  }
}

我需要在Listview中获取它们，并为每个属性和名称添加一列。

我通过JSONUtils网站生成了一个类：

    Public Class Name1

        <JsonProperty("Property 1")>
        Public Property Property1 As Integer

        <JsonProperty("Property 2")>
        Public Property Property2 As Boolean

        <JsonProperty("Property 3")>
        Public Property Property3 As Integer

        <JsonProperty("Property 4")>
        Public Property Property4 As Integer
    End Class

    Public Class Name2

        <JsonProperty("Property 1")>
        Public Property Property1 As Integer

        <JsonProperty("Property 2")>
        Public Property Property2 As Boolean

        <JsonProperty("Property 3")>
        Public Property Property3 As Integer

        <JsonProperty("Property 4")>
        Public Property Property4 As Integer
    End Class

    Public Class NameList

        <JsonProperty("Name 1")>
        Public Property Name1 As Name1

        <JsonProperty("Name 2")>
        Public Property Name2 As Name2
    End Class

但是由于名称的更改，我不得不在运行时动态添加这些类。

接下来，我尝试生成一个看起来像这样的类：

    Public Class NameList

        Public Property Name As String

        <JsonProperty("Property 1")>
        Public Property Property1 As Integer

        <JsonProperty("Property 2")>
        Public Property Property2 As Boolean

        <JsonProperty("Property 3")>
        Public Property Property3 As Integer

        <JsonProperty("Property 4")>
        Public Property Property4 As Integer
    End Class

这是预期的，但是当我运行测试程序时，出现错误：

System.NullReferenceException: "Object reference not set to an instance of an object."

在我的代码下面：

Dim client As New WebClient()
Dim stream As Stream = client.OpenRead("C:\\Filename.json")
Dim reader As New StreamReader(stream)
Dim jsonData As String = reader.ReadToEnd

reader.Close()

Dim allData As JObject = JObject.Parse(jsonData)

Dim nameDataList As New List(Of NameList)

For Each token As JToken In allData("")

      Dim prop As JProperty = token

      If Not prop.Name.StartsWith("_") Then
          nameDataList.Add(New NameList With {
              .Name = prop.Name,
              .Property1 = prop.Value("Property 1"),
              .Property2 = prop.Value("Property 2"),
              .Property3 = prop.Value("Property 3"),
              .Property4 = prop.Value("Property 4")})
      End If

Next

之后是将令牌添加到我的Listview的代码。

此行出现错误：

For Each token As JToken In allData("")

如何避免此错误？

预先感谢：）

Answer 1

allData（“”）没有任何JToken。是[string，JToken]的KeyValuePair。

尝试从代码和As JToken中删除（“”）。像这样：

    For Each obj As KeyValuePair In allData
        Dim name As String = obj.Key
        Dim token As JToken = obj.Value
    Next

https://dotnetfiddle.net/4ZED9z

解析具有相同属性但名称不同的JSON文件

1 个答案: