VB.NET Json Parse

Question

我正在尝试处理下面的JSON输入。代码（底部）抛出

Error reading JObject from JsonReader. 
Current JsonReader item is not an object: StartArray. 
Path '', line 1, position 1.

输入：

[
{
"data": [
    {
    "photos": {
        "data": [
            {
                "id": "1",
                "name": "test Post",
                "images": [
                {
                    "height": 1024,
                    "source": "https://127.0.0.1:8080/image1.png",
                    "width": 1204
                },
                {
                    "height": 1204,
                    "source": "https://127.0.0.1:8080/image2.png",
                    "width": 1204
                }
                ],
            }
        ]
        }
    }
}

代码：

Dim ser As JObject = JObject.Parse(result.ToString)
Dim data As List(Of JToken) = ser.Children().ToList

Dim jsonString As String = Nothing
Dim index As Integer = 0
For Each item As JProperty In data
    item.CreateReader()
    Select Case item.Name
        Case "data"
            jsonString = item.Value.ToString
    End Select
Next

ser = JObject.Parse(jsonString)
data = ser.Children().ToList
For Each item As JProperty In data
    item.CreateReader()
    Select Case item.Name
        Case "photos"
            jsonString = item.Value.ToString
    End Select
Next

ser = JObject.Parse(jsonString)
data = ser.Children().ToList
For Each item As JProperty In data
    item.CreateReader()
    Select Case item.Name
        Case "data"
            For Each comment As JObject In item.Values
                Dim _id As String = comment("id")
                Dim _title As String = comment("title")
                Dim _name As String = comment("name")
                Dim _source As String = comment("source")
                Dim source As List(Of JToken) = item.Value.ToList
                For Each images As JProperty In source
                    item.CreateReader()
                    Select Case item.Name
                        Case "images"
                            Dim _tempsource As String = source("source")
                            _source += _tempsource & vbCrLf
                    End Select
                Next
                Dim _created_time As String = comment("created_time")

                Dim itm As New ListViewItem(_id, 1)
                itm.SubItems.Add(_title)
                itm.SubItems.Add(_name)
                itm.SubItems.Add(_source)
                itm.SubItems.Add(_created_time)

                lvItems.Items.AddRange(New ListViewItem() {itm})
                index += 1
            Next
    End Select
Next

我使用

访问此命名空间

Imports Newtonsoft.Json 
Imports Newtonsoft.Json.Linq

我做错了什么？

Answer 1

我使用JSONLint来调试您的JSON，因为它无效。你必须检查你的消息来源是否发送了无效的JSON，或者在这里发布时有错字。这将是有效的JSON：

[{
    "data": [{
        "photos": {
            "data": [{
                "id": "1",
                "name": "test Post",
                "images": [{
                    "height": 1024,
                    "source": "https://127.0.0.1:8080/image1.png",
                    "width": 1204
                }, {
                    "height": 1204,
                    "source": "https://127.0.0.1:8080/image2.png",
                    "width": 1204
                }]
            }]
        }
    }]
}]

然后，您可以使用JSON Utils或VS本身等工具（将JSON复制到剪贴板并使用编辑＆gt;选择性粘贴＆gt;将JSON粘贴为类）来生成VB类与JSON结构匹配：

Public Class Image
    Public Property height As Integer
    Public Property source As String
    Public Property width As Integer
End Class

Public Class PhotoDatum
    Public Property id As String
    Public Property name As String
    Public Property images As Image()
End Class

Public Class Photos
    Public Property data As PhotoDatum()
End Class

Public Class Datum
    Public Property photos As Photos
End Class

Public Class SER
    Public Property data As Datum()
End Class

无论如何，如果你将上面的类添加到项目中，你可以这样做：

Dim MySER = JsonConvert.DeserializeObject(Of SER)(jsonString)
Dim itm As ListViewItem
Dim MyItems As New List(Of ListViewItem)
For Each d In MySER
    If d.photos IsNot Nothing Then
        For each dd in d.photos.data
            If dd.images IsNot Nothing Then
                For each img In dd.images
                    itm = New ListViewItem(dd.id, 1)
                    itm.SubItems.Add(dd.name)
                    itm.SubItems.Add(img.source)
                    MyItems.Add(itm)
                Next
            End If 
        Next
    End If
Next
lvItems.Items.AddRange(MyItems)

使用结构化对象。我觉得值得一试。我希望它可以帮助你。