.NET DataContractJsonSerializer，嵌套集合让我陷入循环答案

【问题标题】：.NET DataContractJsonSerializer, Nested collections throwing me for a loop.NET DataContractJsonSerializer，嵌套集合让我陷入循环
【发布时间】：2011-04-29 23:11:27
【问题描述】：

我正在研究一个课程，以通过 3 个不同的提供商获取地址的纬度和经度（仅用于比较）。

请注意，这可能看起来很多，但如果您愿意，一些信息仅供参考。 <hr>下面的数据不用看。

我的 Google 地图 DataContract 的工作方式非常出色。但是我的 Bing 和 MapQuest DataContracts 玩得不是很好。我认为问题必须处理 Bing 和 MapQuest 的 JSON 的 嵌套集合，我只是不知道如何处理它们。

这是处理数据的函数。

        ''# Because the JSON Response from Google, MapQuest, and Bing are drastically
        ''# different, we need to consume the response a little differently
        ''# for each API. 


        ''# ##################################
        ''# BING IS BROKEN
        ''# ##################################
        ''# Here we're handling the Bing Provider
        If Provider = apiProvider.Bing Then
            Dim res = DirectCast(serializer.ReadObject(request.GetResponse().GetResponseStream()), BingResponse)
            Dim resources As BingResponse.ResourceSet.Resource = res.resourceSets(0).resources(0)
            Dim point = resources.point
            With coordinates
                .latitude = point.coordinates(0)
                .longitude = point.coordinates(1)
            End With



        ''# ##################################
        ''# GOOGLE WORKS LIKE A CHAMP
        ''# ##################################
            ''# Here we're handling the Google Provider
        ElseIf Provider = apiProvider.Google Then
            Dim res = DirectCast(serializer.ReadObject(request.GetResponse().GetResponseStream()), GoogleResponse)
            Dim resources As GoogleResponse.Result = res.results(0)
            Dim point = resources.geometry.location
            With coordinates
                .latitude = point.lat
                .longitude = point.lng
            End With



        ''# ##################################
        ''# MAPQUEST IS BROKEN
        ''# ##################################
            ''# Here we're handling the MapQuest Provider
        ElseIf Provider = apiProvider.MapQuest Then
            Dim res = DirectCast(serializer.ReadObject(request.GetResponse().GetResponseStream()), MapQuestResponse)
            Dim resources As MapQuestResponse.Result = res.results(0)
            Dim point = resources.locations.latLng
            With coordinates
                .latitude = point.lat
                .longitude = point.lng
            End With
        End If

这是三个 DataContracts

''# A comment to fix SO Code Coloring
<DataContract()>
Public Class BingResponse
    <DataMember()>
    Public Property resourceSets() As ResourceSet()
    <DataContract()>
    Public Class ResourceSet
        <DataMember()>
        Public Property resources() As Resource()
        <DataContract([Namespace]:="http://schemas.microsoft.com/search/local/ws/rest/v1", name:="Location")>
        Public Class Resource
            <DataMember()>
            Public Property point() As m_Point
            <DataContract()>
            Public Class m_Point
                <DataMember()>
                Public Property coordinates() As String()
            End Class
        End Class
    End Class
End Class

<DataContract()>
Public Class GoogleResponse
    <DataMember()>
    Public Property results() As Result()
    <DataContract()>
    Public Class Result
        <DataMember()>
        Public Property geometry As m_Geometry
        <DataContract()>
        Public Class m_Geometry
            <DataMember()>
            Public Property location As m_location
            <DataContract()>
            Public Class m_location
                <DataMember()>
                Public Property lat As String
                <DataMember()>
                Public Property lng As String
            End Class
        End Class
    End Class
End Class

<DataContract()>
Public Class MapQuestResponse
    <DataMember()>
    Public Property results() As Result()
    <DataContract()>
    Public Class Result
        <DataMember()>
        Public Property locations As m_Locations
        <DataContract()>
        Public Class m_Locations
            <DataMember()>
            Public Property latLng As m_latLng
            <DataContract()>
            Public Class m_latLng
                <DataMember()>
                Public Property lat As String
                <DataMember()>
                Public Property lng As String
            End Class
        End Class
    End Class
End Class

在测试 MapQuest 时出现此错误

System.NullReferenceException：对象引用未设置为对象的实例。上线

.latitude = point.lat

在测试 Bing 时出现此错误

System.IndexOutOfRangeException：索引超出了数组的范围。上线

Dim resources As BingResponse.ResourceSet.Resource = res.resourceSets(0).resources(0)

仅供参考，我还将发布每个 JSON 响应的样子。

谷歌地图

{
  "status": "OK",
  "results": [ {
    "types": [ "bus_station", "transit_station" ],
    "formatted_address": "Microsoft Way & Microsoft ACS, Redmond, WA 98052, USA",
    "address_components": [ {
      "long_name": "Microsoft Way & Microsoft ACS",
      "short_name": "Microsoft Way & Microsoft ACS",
      "types": [ "bus_station", "transit_station" ]
    }, {
      "long_name": "Redmond",
      "short_name": "Redmond",
      "types": [ "locality", "political" ]
    }, {
      "long_name": "East Seattle",
      "short_name": "East Seattle",
      "types": [ "administrative_area_level_3", "political" ]
    }, {
      "long_name": "King",
      "short_name": "King",
      "types": [ "administrative_area_level_2", "political" ]
    }, {
      "long_name": "Washington",
      "short_name": "WA",
      "types": [ "administrative_area_level_1", "political" ]
    }, {
      "long_name": "United States",
      "short_name": "US",
      "types": [ "country", "political" ]
    }, {
      "long_name": "98052",
      "short_name": "98052",
      "types": [ "postal_code" ]
    } ],
    "geometry": {
      "location": {
        "lat": 47.6397018,
        "lng": -122.1305080
      },
      "location_type": "APPROXIMATE",
      "viewport": {
        "southwest": {
          "lat": 47.6365542,
          "lng": -122.1336556
        },
        "northeast": {
          "lat": 47.6428494,
          "lng": -122.1273604
        }
      }
    },
    "partial_match": true
  }, {
    "types": [ "bus_station", "transit_station" ],
    "formatted_address": "Microsoft Way & NE 36th St, Redmond, WA 98052, USA",
    "address_components": [ {
      "long_name": "Microsoft Way & NE 36th St",
      "short_name": "Microsoft Way & NE 36th St",
      "types": [ "bus_station", "transit_station" ]
    }, {
      "long_name": "Redmond",
      "short_name": "Redmond",
      "types": [ "locality", "political" ]
    }, {
      "long_name": "East Seattle",
      "short_name": "East Seattle",
      "types": [ "administrative_area_level_3", "political" ]
    }, {
      "long_name": "King",
      "short_name": "King",
      "types": [ "administrative_area_level_2", "political" ]
    }, {
      "long_name": "Washington",
      "short_name": "WA",
      "types": [ "administrative_area_level_1", "political" ]
    }, {
      "long_name": "United States",
      "short_name": "US",
      "types": [ "country", "political" ]
    }, {
      "long_name": "98052",
      "short_name": "98052",
      "types": [ "postal_code" ]
    } ],
    "geometry": {
      "location": {
        "lat": 47.6420593,
        "lng": -122.1306990
      },
      "location_type": "APPROXIMATE",
      "viewport": {
        "southwest": {
          "lat": 47.6389117,
          "lng": -122.1338466
        },
        "northeast": {
          "lat": 47.6452069,
          "lng": -122.1275514
        }
      }
    },
    "partial_match": true
  }, {
    "types": [ "bus_station", "transit_station" ],
    "formatted_address": "Microsoft Way & NE 31ST St, Redmond, WA 98052, USA",
    "address_components": [ {
      "long_name": "Microsoft Way & NE 31ST St",
      "short_name": "Microsoft Way & NE 31ST St",
      "types": [ "bus_station", "transit_station" ]
    }, {
      "long_name": "Redmond",
      "short_name": "Redmond",
      "types": [ "locality", "political" ]
    }, {
      "long_name": "East Seattle",
      "short_name": "East Seattle",
      "types": [ "administrative_area_level_3", "political" ]
    }, {
      "long_name": "King",
      "short_name": "King",
      "types": [ "administrative_area_level_2", "political" ]
    }, {
      "long_name": "Washington",
      "short_name": "WA",
      "types": [ "administrative_area_level_1", "political" ]
    }, {
      "long_name": "United States",
      "short_name": "US",
      "types": [ "country", "political" ]
    }, {
      "long_name": "98052",
      "short_name": "98052",
      "types": [ "postal_code" ]
    } ],
    "geometry": {
      "location": {
        "lat": 47.6380959,
        "lng": -122.1318050
      },
      "location_type": "APPROXIMATE",
      "viewport": {
        "southwest": {
          "lat": 47.6349483,
          "lng": -122.1349526
        },
        "northeast": {
          "lat": 47.6412435,
          "lng": -122.1286574
        }
      }
    },
    "partial_match": true
  }, {
    "types": [ "route" ],
    "formatted_address": "Microsoft w Campus Acrd, Redmond, WA, USA",
    "address_components": [ {
      "long_name": "Microsoft w Campus Acrd",
      "short_name": "Microsoft w Campus Acrd",
      "types": [ "route" ]
    }, {
      "long_name": "Redmond",
      "short_name": "Redmond",
      "types": [ "locality", "political" ]
    }, {
      "long_name": "East Seattle",
      "short_name": "East Seattle",
      "types": [ "administrative_area_level_3", "political" ]
    }, {
      "long_name": "King",
      "short_name": "King",
      "types": [ "administrative_area_level_2", "political" ]
    }, {
      "long_name": "Washington",
      "short_name": "WA",
      "types": [ "administrative_area_level_1", "political" ]
    }, {
      "long_name": "United States",
      "short_name": "US",
      "types": [ "country", "political" ]
    } ],
    "geometry": {
      "location": {
        "lat": 47.6582970,
        "lng": -122.1414390
      },
      "location_type": "GEOMETRIC_CENTER",
      "viewport": {
        "southwest": {
          "lat": 47.6559394,
          "lng": -122.1435435
        },
        "northeast": {
          "lat": 47.6622346,
          "lng": -122.1372482
        }
      },
      "bounds": {
        "southwest": {
          "lat": 47.6577719,
          "lng": -122.1433446
        },
        "northeast": {
          "lat": 47.6604021,
          "lng": -122.1374471
        }
      }
    },
    "partial_match": true
  } ]
}

必应地图

{ "authenticationResultCode" : "ValidCredentials",
  "brandLogoUri" : "http://dev.virtualearth.net/Branding/logo_powered_by.png",
  "copyright" : "Copyright © 2011 Microsoft and its suppliers. All rights reserved. This API cannot be accessed and the content and any results may not be used, reproduced or transmitted in any manner without express written permission from Microsoft Corporation.",
  "resourceSets" : [ { "estimatedTotal" : 1,
        "resources" : [ { "__type" : "Location:http://schemas.microsoft.com/search/local/ws/rest/v1",
              "address" : { "addressLine" : "1 Microsoft Way",
                  "adminDistrict" : "WA",
                  "countryRegion" : "United States",
                  "formattedAddress" : "1 Microsoft Way, Redmond, WA 98052",
                  "locality" : "Redmond",
                  "postalCode" : "98052"
                },
              "bbox" : [ 47.636682837606166,
                  -122.13698544771381,
                  47.644408272747519,
                  -122.12169881991093
                ],
              "confidence" : "High",
              "entityType" : "Address",
              "name" : "1 Microsoft Way, Redmond, WA 98052",
              "point" : { "coordinates" : [ 47.640545555176843,
                      -122.12934213381237
                    ],
                  "type" : "Point"
                }
            } ]
      } ],
  "statusCode" : 200,
  "statusDescription" : "OK",
  "traceId" : "3d0dd6c4ea1f4c4ba6f9c7211a5abf75|BAYM001222|02.00.82.2800|BY2MSNVM001058"
}

地图任务

{ "info" : { "copyright" : { "imageAltText" : "© 2011 MapQuest, Inc.",
          "imageUrl" : "http://tile21.mqcdn.com/res/mqlogo.gif",
          "text" : "© 2011 MapQuest, Inc."
        },
      "messages" : [  ],
      "statuscode" : 0
    },
  "options" : { "ignoreLatLngInput" : false,
      "maxResults" : -1,
      "thumbMaps" : true
    },
  "results" : [ { "locations" : [ { "adminArea1" : "US",
              "adminArea1Type" : "Country",
              "adminArea3" : "WA",
              "adminArea3Type" : "State",
              "adminArea4" : "King County",
              "adminArea4Type" : "County",
              "adminArea5" : "Redmond",
              "adminArea5Type" : "City",
              "displayLatLng" : { "lat" : 47.674197999999997,
                  "lng" : -122.1203
                },
              "dragPoint" : false,
              "geocodeQuality" : "CITY",
              "geocodeQualityCode" : "A5XCX",
              "latLng" : { "lat" : 47.674197999999997,
                  "lng" : -122.1203
                },
              "linkId" : 0,
              "mapUrl" : "http://www.mapquestapi.com/staticmap/v3/getmap?type=map&size=225,160&pois=purple-1,47.674198,-122.1203,0,0|&center=47.674198,-122.1203&zoom=9&key=Fmjtd|luu22q01ng,2n=o5-h6rnq&rand=-47567557",
              "postalCode" : "",
              "sideOfStreet" : "N",
              "street" : "",
              "type" : "s"
            } ],
        "providedLocation" : { "location" : "1 Microsoft Way, Redmon WA" }
      } ]
}

加法

【问题讨论】：

没关系，没看到滚动条。
我对其进行了编辑以专注于相关数据。
在您的数据合同中，作为 mapquest 的数字返回的 lat/lng 是否需要是小数？编辑：不，谷歌地图是一样的。我会看答案的，我很感兴趣。
我添加了一个屏幕截图，显示 latLng 即将为空
公共财产位置不应该作为 m_Locations 是公共财产位置（）作为 m_Locations（）吗？我假设这是 VB 中的数组表示法。看来您是从 Array 对象中获取 latLng 而不是数组中位置的实例。

标签： asp.net json datacontract datacontractjsonserializer

【解决方案1】：

地图任务：

Public Property locations As m_Locations 不应该是Public Property locations() As m_Locations() 吗？我假设这是 VB 中的数组表示法。看起来您是从 Array 对象中获取 latLng 而不是数组中位置的实例。

找到了一个similar question，其中包含相同响应的数据合同（已接受的答案）。寻找差异但尚未发现它们......

【讨论】：

哈哈，是的。这正是 MapQuest 的问题。
事实证明我在使用 BING 时遇到的问题是我发送了城市和省份，它不喜欢
很高兴我能帮忙，它总是需要第二双眼睛。
你打赌。有趣的是，小括号可以让人想挖出他们的眼睛。再次感谢！