c# - C# Azure MongoDB Linq Near 查询

问题描述

我正在尝试将带有位置点的查询发送到 Azure Cosmos DB (MongoDB) 并获取该点附近的位置。我从这里得到了大部分信息。我正在使用Microsoft.Azure.Documents.Spatial;.

到目前为止，我已经尝试了许多其他旧帖子的解决方案，但对我没有任何帮助。

我的班级定义：

 public class Place : INotifyPropertyChanged
{
    [BsonId(IdGenerator = typeof(CombGuidGenerator))]
    public Guid Id { get; set; }

    Point _location;
    [BsonElement("Location")]
    public Point Location
    {
        get => _location;
        set
        {
            if (_location == value)
                return;

            _location = value;

            HandlePropertyChanged();
        }
    }

    long _addedDate;
    [BsonElement("AddedDate")]
    public long AddedDate
    {
        get => _addedDate;
        set
        {
            if (_addedDate == value)
                return;

            _addedDate = value;

            HandlePropertyChanged();
        }
    }

    void HandlePropertyChanged([CallerMemberName]string propertyName = "")
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }

    public event PropertyChangedEventHandler PropertyChanged;
}

蒙哥连接：

 // APIKeys.Connection string is found in the portal under the "Connection String" blade
                MongoClientSettings settings = MongoClientSettings.FromUrl(
                  new MongoUrl(APIKeys.ConnectionString)
                );

                settings.SslSettings =
                    new SslSettings() { EnabledSslProtocols = SslProtocols.Tls12 };

                // Initialize the client
                var mongoClient = new MongoClient(settings);

                // This will create or get the database
                var db = mongoClient.GetDatabase(dbName);

                // This will create or get the collection
                var collectionSettings = new MongoCollectionSettings { ReadPreference = ReadPreference.Nearest };
                PlacesCollection = db.GetCollection<Place>(collectionName, collectionSettings);

询问：

var point = new Point(22, -5);
IMongoQueryable<Place> query = PlacesCollection.AsQueryable().Where(p => p.Location.Distance(point) < 30000);

return query.ToList();

我收到以下错误return query.ToList()：

未处理的异常：

System.InvalidOperationException：不支持 {document}{Location}.Distance(value(Microsoft.Azure.Documents.Spatial.Point))。

我不明白什么是不支持的，也不知道如何为此创建正确的查询。任何想法？

编辑：调用堆栈

0xE0 in XamFormsMaps.Core.Services.MongoService.GetPlacesNear at C:\Users\Role\source\repos\XamFormsMaps\XamFormsMaps\XamFormsMaps.Core\Services\MongoService.cs:84,13  C#
[External Code] 
0x20 in XamFormsMaps.Core.Services.DatabaseService.GetPlacesNear at C:\Users\Role\source\repos\XamFormsMaps\XamFormsMaps\XamFormsMaps.Core\Services\DatabaseService.cs:20,13    C#
0x7A in XamFormsMaps.Core.ViewModels.MapViewModel.GetPlacesAsync at C:\Users\Role\source\repos\XamFormsMaps\XamFormsMaps\XamFormsMaps.Core\ViewModels\MapViewModel.cs:112,17    C#
0x6D in XamFormsMaps.Core.Pages.MapPage.<-ctor<-ctor>b__0_1>d at C:\Users\Role\source\repos\XamFormsMaps\XamFormsMaps\XamFormsMaps.Core\Pages\MapPage.xaml.cs:27,17 C#

标签： c#.netmongodbazure-cosmosdb

c# - C# Azure MongoDB Linq Near 查询

问题描述

解决方案

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