Write a shape file in Xamarin.forms bug

[benabdelkrim]

[DGuidi]

please post the complete code you're testing, from this I don't see why the line highlighted can throw a "ArgumentNullException" actually. No similar "throws" in the source code

I suspect the error is in attributes dictionary...

[benabdelkrim]

[FObermaier]

Posting images of your VisualStudio instance is not useful.
Please set up a minimum working sample project for us to test your code.

[benabdelkrim]

string path;
string C_postal = "C_postal";
string Type_bat = "Type_bat";
string X_coord = "X_coord";
string Y_coord = "Y_coord";
//create geometry factory
GeometryFactory geomFactory = NtsGeometryServices.Instance.CreateGeometryFactory();
//create the default table with fields - alternately use DBaseField classes
AttributesTable attributes1 = new AttributesTable();
attributes1.Add(C_postal, "40050");
attributes1.Add(Type_bat, "Immeuble");
attributes1.Add(X_coord, "300000");
attributes1.Add(Y_coord, "5000000");
AttributesTable attributes2 = new AttributesTable();
attributes2.Add(C_postal, "40050");
attributes2.Add(Type_bat, "Using");
attributes2.Add(X_coord, "300200");
attributes2.Add(Y_coord, "5000300");
//create geometries and features
Geometry geometry1 = geomFactory.CreatePoint(new Coordinate(300000, 5000000));
Geometry geometry2 = geomFactory.CreatePoint(new Coordinate(300200, 5000300));
Feature feat1 = new Feature(geometry1, attributes1);
Feature feat2 = new Feature(geometry2, attributes2);
//create attribute list
IList features = new List() { feat1, feat2 };
path = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData), "shape");
ShapefileDataWriter writer = new ShapefileDataWriter(path);
writer.Header = ShapefileDataWriter.GetHeader(features[0], features.Count);
System.Collections.IList featList = (System.Collections.IList)features;
writer.Write(features);

[benabdelkrim]

this code is working in application desktop c# but in Xamarin.forms not working, i don't know why ?

[FObermaier]

I'm still missing a project file, the code you posted is just a function. Now, to get to where you are at, we do have to put in effort to set up a project that uses Xamairn.Forms, that eventually invokes your code. Please provide a minimum working sample project for us to test your code.

[benabdelkrim]

thank you for find the code in this link
https://www.swisstransfer.com/d/c1fda1a0-e909-4d7f-a992-e86e0970d66f

[DGuidi]

this code works in .net, I made small changes

string path;
            string C_postal = "C_postal";
            string Type_bat = "Type_bat";
            string X_coord = "X_coord";
            string Y_coord = "Y_coord";
            //create geometry factory
            var geomFactory = NtsGeometryServices.Instance.CreateGeometryFactory();
            //create the default table with fields - alternately use DBaseField classes
            var attributes1 = new AttributesTable();
            attributes1.Add(C_postal, "40050");
            attributes1.Add(Type_bat, "Immeuble");
            attributes1.Add(X_coord, "300000");
            attributes1.Add(Y_coord, "5000000");
            var attributes2 = new AttributesTable();
            attributes2.Add(C_postal, "40050");
            attributes2.Add(Type_bat, "Using");
            attributes2.Add(X_coord, "300200");
            attributes2.Add(Y_coord, "5000300");
            //create geometries and features
            Geometry geometry1 = geomFactory.CreatePoint(new Coordinate(300000, 5000000));
            Geometry geometry2 = geomFactory.CreatePoint(new Coordinate(300200, 5000300));
            var feat1 = new Feature(geometry1, attributes1);
            var feat2 = new Feature(geometry2, attributes2);
            //create attribute list
            var features = new List<IFeature>() { feat1, feat2 };
            path = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData), "shape");
            var writer = new ShapefileDataWriter(path);
            writer.Header = ShapefileDataWriter.GetHeader(features[0], features.Count);
            writer.Write(features);

[benabdelkrim]

it still the problem ! even i separate the Header !
var writer = new ShapefileDataWriter(path);
writer.Header = ShapefileDataWriter.GetHeader(features[0], features.Count);
Other thing this code is working in .NET but in xamarin.forms i have this problem

[DGuidi]

can you post the stack trace? can be helpful to investigate what is the method actually throwing the exception

[FObermaier]

The cause for this to fail is probably the failure of the initialization of NetTopologySuite.IO.DbaseEncodingUtility.
Maybe some of the initial codepages are not available for Android?

[benabdelkrim]

Please I need to know if there's a solution to read/write a shapefile in Xamarin.forms. I really appreciate your help.

Thanks in advance.