通过javascript从json字符串中提取值

时间:2012-05-30 22:42:26

标签: javascript json

我有一个以JSON格式返回结果的web服务 在Javascript中,我想循环遍历这些结果,以便我可以将它们显示给用户。

我定义了以下类:

Public Class PointsOfInterest
    Public Property hotspots() As List(Of Hotspot)
        Get
            Return m_hotspots
        End Get
        Set(value As List(Of Hotspot))
            m_hotspots = value
        End Set
    End Property
    Private m_hotspots As List(Of Hotspot)
    Public Property errorString() As String
        Get
            Return m_errorString
        End Get
        Set(value As String)
            m_errorString = value
        End Set
    End Property
    Private m_errorString As String
    Public Property errorCode() As Integer
        Get
            Return m_errorCode
        End Get
        Set(value As Integer)
            m_errorCode = value
        End Set
    End Property
    Private m_errorCode As Integer
End Class

Public Class Hotspot
    Private m_id As String
    Public Property id() As String
        Get
            Return m_id
        End Get
        Set(value As String)
            m_id = value
        End Set
    End Property

    Public Property anchor() As anchor
        Get
            Return m_anchor
        End Get
        Set(value As anchor)
            m_anchor = value
        End Set
    End Property
    Private m_anchor As anchor


    Public Property text() As textprop
        Get
            Return _text
        End Get
        Set(value As textprop)
            _text = value
        End Set
    End Property
    Private _text As textprop


    Public Property imageURL() As String
        Get
            Return _imageURL
        End Get
        Set(value As String)
            _imageURL = value
        End Set
    End Property
    Private _imageURL As String

    Public Property actions() As List(Of action)
        Get
            Return _actions
        End Get
        Set(value As List(Of action))
            _actions = value
        End Set
    End Property
    Private _actions As List(Of action)

End Class

Public Class anchor
    Public Property geolocation() As geoloc
        Get
            Return _geoloc
        End Get
        Set(value As geoloc)
            _geoloc = value
        End Set
    End Property
    Private _geoloc As geoloc

End Class

Public Class textprop
    Public Property title() As String
        Get
            Return _title
        End Get
        Set(value As String)
            _title = value
        End Set
    End Property
    Private _title As String
    Public Property description() As String
        Get
            Return _description
        End Get
        Set(value As String)
            _description = value
        End Set
    End Property
    Private _description As String
    Public Property footnote() As String
        Get
            Return _footnote
        End Get
        Set(value As String)
            _footnote = value
        End Set
    End Property
    Private _footnote As String

End Class


Public Class geoloc
    Public Property lat() As String
        Get
            Return _lat
        End Get
        Set(value As String)
            _lat = value
        End Set
    End Property
    Private _lat As String
    Public Property lon() As String
        Get
            Return _lon
        End Get
        Set(value As String)
            _lon = value
        End Set
    End Property
    Private _lon As String
End Class

Public Class action
    Public Property uri() As String
        Get
            Return _uri
        End Get
        Set(value As String)
            _uri = value
        End Set
    End Property
    Private _uri As String

    Public Property label() As String
        Get
            Return _label
        End Get
        Set(value As String)
            _label = value
        End Set
    End Property
    Private _label As String
    Public Property contentType() As String
        Get
            Return _contentType
        End Get
        Set(value As String)
            _contentType = value
        End Set
    End Property
    Private _contentType As String
    Public Property method() As String
        Get
            Return _method
        End Get
        Set(value As String)
            _method = value
        End Set
    End Property
    Private _method As String
    Public Property activityType() As Integer
        Get
            Return _activityType
        End Get
        Set(value As Integer)
            _activityType = value
        End Set
    End Property
    Private _activityType As Integer
    Public Property showActivity() As Boolean
        Get
            Return _showActivity
        End Get
        Set(value As Boolean)
            _showActivity = value
        End Set
    End Property
    Private _showActivity As Boolean
    Public Property activityMessage() As String
        Get
            Return _activityMessage
        End Get
        Set(value As String)
            _activityMessage = value
        End Set
    End Property
    Private _activityMessage As String

End Class   

我通过JSON中的网络服务返回这些内容:http://www.wunderwedding.com/weddingservice.svc/api/?t=1&cid=1&pid=6&lat=52&lng=5&d=10000&city=nijmegen&field1=0&field2=0&field3=0&field4=0&hasphoto=0&hasvideo=0&minrating=0&lang=nl

现在,如果我想要读取第3个结果的tel属性(在本例中为0348551532) 我该怎么办呢? 它是否类似于XSLT,我可以使用表达式进行选择?

1 个答案:

答案 0 :(得分:1)

在JavaScript中,我假设您使用的是支持AJAX的jQuery或ExtJS。在客户端获得JSON后,您将解码Web服务结果(如果您在没有特殊工具包的情况下阅读JSON,则使用Ext.decode或eval(“”)。)

一旦你对JSON进行了解码,它就可以在JavaScript中使用了。

示例:

var json = [Function that decodes JSON text];
var uriInfo = json.hotspots[2].actions[1].uri;

如果您使用的是FireFox,则可以安装名为FireBug的插件。这将允许您处理这类事情。使用该工具,您可以调用console.dir(json);在JavaScript中看到javascript等所见的整个结构。