json - 在 Visual Basic 中反序列化 JSON

Question

基本上，我正在尝试使用 4chan JSON API 解析来自 4chan 线程的评论。 https://github.com/4chan/4chan-API

基本上，有一个称为 input 的富文本框，另一个称为 post_text_box。我试图做的是让来自 4chan 线程的 JSON 输入到输入文本框中，并从该 JSON 中提取注释并显示在输出文本框中

但是，每当我尝试单击 Go 按钮时，什么也没有发生。

到目前为止，这是我的代码

Imports System.Web.Script.Serialization
Imports Newtonsoft.Json
Imports Newtonsoft.Json.Linq

Public Class Form1
    Private Sub start_button_Click(sender As Object, e As EventArgs) Handles start_button.Click
        Dim j As Object = New JavaScriptSerializer().Deserialize(Of Post)(input.Text)

        post_text_box.Text = j.com
    End Sub
End Class

Public Class Rootobject
    Public Property posts() As Post
End Class

Public Class Post
    Public Property no As Integer
    Public Property now As String
    Public Property name As String
    Public Property com As String
    Public Property filename As String
    Public Property ext As String
    Public Property w As Integer
    Public Property h As Integer
    Public Property tn_w As Integer
    Public Property tn_h As Integer
    Public Property tim As Long
    Public Property time As Integer
    Public Property md5 As String
    Public Property fsize As Integer
    Public Property resto As Integer
    Public Property bumplimit As Integer
    Public Property imagelimit As Integer
    Public Property replies As Integer
    Public Property images As Integer
End Class

Answer 1

由于您正在导入 Newtonsoft.Json ，您只需使用 JsonConvert.DeserializeObject<T>(String) method:

Dim exampleJson As String = "{ 'no':'123', 'name':'Some Name', 'com':'This is a comment'}"
Dim post As Post = JsonConvert.DeserializeObject(Of Post)(exampleJson)
Dim com As String = post.com
post_text_box.Text = com

或者，如果您不想为 Post 创建一个类，您可以使用 JsonConvert.DeserializeAnonymousType<T>(String, T) :

Dim exampleJson As String = "{ 'no':'123', 'name':'Some Name', 'com':'This is a comment'}"
Dim tempPost = New With {Key .com = ""}
Dim post = JsonConvert.DeserializeAnonymousType(exampleJson, tempPost)
Dim com As String = post.com
post_text_box.Text = com

编辑 :看起来您正在从 API 获取一个数组:

{
    "posts" : [{
            "no" : 38161812,
            "now" : "11\/19\/13(Tue)15:18",
            "name" : "Anonymous",
            "com" : ‌​ "testing thread for JSON stuff",
            "filename" : "a4c",
            "ext" : ".png",
            "w" : 386,
            "h" : 378,
            "tn_w" : 250,
            "tn_h" : 244,
            "tim" ‌​ : 1384892303386,
            "time" : 1384892303,
            "md5" : "tig\/aNmBqB+zOZY5upx1Fw==",
            "fsize" : 6234,
            "‌​resto" : 0,
            "bumplimit" : 0,
            "imagelimit" : 0,
            "replies" : 0,
            "images" : 0
        }
    ]
}

在这种情况下，您需要将正在反序列化的类型更改为 Post() :

首先，添加另一个小包装类:

Public Class PostWrapper
    Public posts() As Post
End Class

然后调整你的反序列化代码:

Dim json As String = input_box.Text
Dim postWrapper = JsonConvert.DeserializeObject(Of PostWrapper)(json) ' Deserialize array of Post objects
Dim posts = postWrapper.posts

If posts.Length = 1 Then ' or whatever condition you prefer
    post_text_box.Text = posts(0).com
End If