Parsing Multidimensional JSON Array with Newtonsoft Json.NET
Instead of declaring a lot of classes, I would parse the json string as follows
JArray jArr = (JArray)JsonConvert.DeserializeObject(jsonstr);
foreach (var item in jArr)
{
foreach(var subitem in item["TrailCoordinates"])
{
Console.WriteLine(subitem["Longitude"] + " " + subitem["Latitude"]);
}
}
If monotouch supports dynamic
you can also write
dynamic jArr2 = JsonConvert.DeserializeObject(jsonstr);
foreach (dynamic item in jArr2)
{
foreach (var subitem in item.TrailCoordinates)
{
Console.WriteLine(subitem.Longitude + " " + subitem.Latitude);
}
}
You can even use Linq
JArray jArr = (JArray)JsonConvert.DeserializeObject(jsonstr);
var coords = jArr
.Select(x => x["TrailCoordinates"])
.SelectMany(x=>x)
.Where(x => x["TrailId"].ToString() == "40")
.Select(x => new { Lat = double.Parse(x["Latitude"].ToString()), Lon=double.Parse(x["Longitude"].ToString()) })
.ToArray();
k1komans
Updated on June 05, 2022Comments
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k1komans about 2 years
I have Json returning as the following:
[{"CreatedBy":"GIS_DB","CreatedDate":"3/8/2012 10:44:00 AM","Id":39,"ModifiedBy":"","ModifiedDate":"","Name":"CF-39","StatusId":1,"TrailCoordinates":[{"CreatedBy":"GIS_DB","CreatedDate":"3/8/2012 10:44:00 AM","Id":1637,"Latitude":32.76004207,"Longitude":-97.34006853,"ModifiedBy":"","ModifiedDate":"","SortOrder":1,"TrailId":39},{"CreatedBy":"GIS_DB","CreatedDate":"3/8/2012 10:44:00 AM","Id":1638,"Latitude":32.76004333,"Longitude":-97.34012121,"ModifiedBy":"","ModifiedDate":"","SortOrder":2,"TrailId":39}]},{"CreatedBy":"GIS_DB","CreatedDate":"3/8/2012 10:44:00 AM","Id":40,"ModifiedBy":"","ModifiedDate":"","Name":"CF-40","StatusId":1,"TrailCoordinates":[{"CreatedBy":"GIS_DB","CreatedDate":"3/8/2012 10:44:00 AM","Id":3755,"Latitude":32.76034332,"Longitude":-97.3402069,"ModifiedBy":"","ModifiedDate":"","SortOrder":1,"TrailId":40},{"CreatedBy":"GIS_DB","CreatedDate":"3/8/2012 10:44:00 AM","Id":3756,"Latitude":32.76019181,"Longitude":-97.3402448,"ModifiedBy":"","ModifiedDate":"","SortOrder":2,"TrailId":40}]}]
These are my classes...
public class Trails { [MonoTouch.Foundation.Preserve] public Trails(){ TrailCoord = new List<trailcoords>();} [MonoTouch.Foundation.Preserve, JsonProperty("Name")] public string TrailName { get; set; } [MonoTouch.Foundation.Preserve, JsonProperty("StatusId")] public int StatusId { get; set; } [MonoTouch.Foundation.Preserve, JsonProperty("TrailCoordinates")] public List<trailcoords> TrailCoord { get; set; } // public trailcoords public Trails (string trailname, int statusid, List<trailcoords> trailcoord) { TrailName = trailname; StatusId = statusid; TrailCoord = trailcoord; } } public class trailcoords { [MonoTouch.Foundation.Preserve] public trailcoords(){} [MonoTouch.Foundation.Preserve, JsonProperty("TrailId")] public string TrailId { get; set; } [MonoTouch.Foundation.Preserve, JsonProperty("Latitude")] public double Latitude { get; set; } [MonoTouch.Foundation.Preserve, JsonProperty("Longitude")] public double Longitude { get; set; } public trailcoords (string trailid, double latitude, double longitude) { TrailId = trailid; Latitude = latitude; Longitude = longitude; } } List<Trails> Posts = JsonConvert.DeserializeObject<List<Trails>> ( json );
So from here I am not sure how I would access the Latitude and Longitude items in my list. I can access things like TrailName no problem but not sure what i'm doing wrong with the items in the array within the array. I would like to add them so that I can plot them as lines in a structure similar to this that I made (hardcoded values):
CLLocationCoordinate2D[] tmpTrail1 = new CLLocationCoordinate2D[]{ new CLLocationCoordinate2D(32.751531, -97.361755), new CLLocationCoordinate2D(32.751451, -97.356625), new CLLocationCoordinate2D(32.751500, -97.332077), }; CLLocationCoordinate2D[] tmpTrail2 = new CLLocationCoordinate2D[] { new CLLocationCoordinate2D(32.727353, -97.361139), new CLLocationCoordinate2D(32.747731, -97.359896), new CLLocationCoordinate2D(32.765735, -97.360360), }; _trailOverlayPoints = new List<CLLocationCoordinate2D[]>(); _trailOverlayPoints.Add(tmpTrail1); _trailOverlayPoints.Add(tmpTrail2);
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k1komans about 12 yearsThanks this is great! Using Linq would I be able to put in a "where" clause so that it only returns coordinates for a specific trail?