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ArcGIS Runtime SDK for .NET

Create and save KML file

This code sample is available for these platforms:
View Sample on GitHub

Construct a KML document and save it as a KMZ file.

Create and save KML file

Use case

If you need to create and save data on the fly, you can use KML to create points, lines, and polygons by sketching on the map, customizing the style, and serializing them as KML nodes in a KML Document. Once complete, you can share the KML data with others that are using a KML reading application, such as ArcGIS Earth.

How to use the sample

Click on one of the buttons in the middle row to start adding a geometry. Click on the map view to place vertices. Click the "Complete Sketch" button to add the geometry to the KML document as a new KML placemark. Use the style interface to edit the style of the placemark. If you do not wish to set a style, click the "Don't Apply Style" button. When you are finished adding KML nodes, click on the "Save KMZ file" button to save the active KML document as a .kmz file on your system. Use the "Reset" button to clear the current KML document and start a new one.

How it works

  1. Create a KmlDocument
  2. Create a KmlDataset using the KmlDocument.
  3. Create a KmlLayer using the KmlDataset and add it to Map.OperationalLayers.
  4. Create Geometry using SketchEditor.
  5. Project that Geometry to WGS84 using GeometryEngine.Project.
  6. Create a KmlGeometry object using that projected Geometry.
  7. Create a KmlPlacemark using the KmlGeometry.
  8. Add the KmlPlacemark to the KmlDocument.
  9. Set the KmlStyle for the KmlPlacemark.
  10. When finished with adding KmlPlacemark nodes to the KmlDocument, save the KmlDocument to a file using the SaveAsAsync method.

Relevant API

  • GeometryEngine.Project
  • KmlDataset
  • KmlDocument
  • KmlGeometry
  • KmlLayer
  • KmlNode.SaveAsASync
  • KmlPlacemark
  • KmlStyle
  • SketchEditor

Tags

Keyhole, KML, KMZ, OGC

Sample Code

<ContentPage
    x:Class="ArcGISRuntimeXamarin.Samples.CreateAndSaveKmlFile.CreateAndSaveKmlFile"
    xmlns="http://xamarin.com/schemas/2014/forms"
    xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
    xmlns:controls="clr-namespace:Windows.UI.Xaml.Controls;assembly=Windows.Foundation.UniversalApiContract"
    xmlns:esriUI="clr-namespace:Esri.ArcGISRuntime.Xamarin.Forms;assembly=Esri.ArcGISRuntime.Xamarin.Forms"
    xmlns:local="clr-namespace:ArcGISRuntimeXamarin.Samples.CreateAndSaveKmlFile">
    <ContentPage.Resources>
        <ResourceDictionary>
            <local:ImageConverter x:Key="imageConverter" />
            <local:ColorConverter x:Key="colorConverter" />
        </ResourceDictionary>
    </ContentPage.Resources>
    <Grid>
        <Grid x:Name="MainUI">
            <Grid.RowDefinitions>
                <RowDefinition Height="auto" />
                <RowDefinition Height="*" />
                <RowDefinition Height="auto" />
                <RowDefinition Height="auto" />
            </Grid.RowDefinitions>
            <esriUI:MapView
                x:Name="MyMapView"
                Grid.Row="0"
                Grid.RowSpan="2" />
            <Grid x:Name="StatusGrid" BackgroundColor="DimGray">
                <Label
                    x:Name="Status"
                    Grid.Row="0"
                    Margin="5"
                    HorizontalOptions="FillAndExpand"
                    Text="Select the type of feature you would like to add."
                    TextColor="White" />
            </Grid>
            <Grid Grid.Row="2">
                <Grid x:Name="ShapeGrid">
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width="*" />
                        <ColumnDefinition Width="*" />
                        <ColumnDefinition Width="*" />
                    </Grid.ColumnDefinitions>
                    <Button
                        Grid.Column="0"
                        Clicked="Edit_Click"
                        Text="Point" />
                    <Button
                        Grid.Column="1"
                        Clicked="Edit_Click"
                        Text="Polyline" />
                    <Button
                        Grid.Column="2"
                        Clicked="Edit_Click"
                        Text="Polygon" />
                </Grid>
                <Button
                    x:Name="CompleteButton"
                    Clicked="Complete_Click"
                    IsVisible="False"
                    Text="Complete Geometry" />
            </Grid>
            <Grid x:Name="SaveResetGrid" Grid.Row="3">
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="*" />
                    <ColumnDefinition Width="*" />
                </Grid.ColumnDefinitions>
                <Button
                    Grid.Column="0"
                    Clicked="Save_Click"
                    Text="Save" />
                <Button
                    Grid.Column="1"
                    Clicked="Reset_Click"
                    Text="Reset" />
            </Grid>
        </Grid>
        <Grid x:Name="StyleUI" IsVisible="False">
            <Grid.RowDefinitions>
                <RowDefinition Height="auto" />
                <RowDefinition Height="*" />
                <RowDefinition Height="auto" />
                <RowDefinition Height="auto" />
            </Grid.RowDefinitions>
            <Label
                Grid.Row="0"
                Margin="5"
                HorizontalTextAlignment="Center"
                Text="Select a style for the placemark." />
            <ListView
                x:Name="IconPicker"
                Grid.Row="1"
                ItemSelected="Apply_Style_Click">
                <ListView.ItemTemplate>
                    <DataTemplate>
                        <ImageCell ImageSource="{Binding Path=., Converter={StaticResource imageConverter}}" />
                    </DataTemplate>
                </ListView.ItemTemplate>
            </ListView>
            <ListView
                x:Name="ColorPicker"
                Grid.Row="1"
                IsVisible="False"
                ItemSelected="Apply_Style_Click">
                <ListView.ItemTemplate>
                    <DataTemplate>
                        <ViewCell>
                            <BoxView Color="{Binding Path=., Converter={StaticResource colorConverter}}" />
                        </ViewCell>
                    </DataTemplate>
                </ListView.ItemTemplate>
            </ListView>
            <Button
                Grid.Row="3"
                Clicked="No_Style_Click"
                Text="Dont Apply Style" />
        </Grid>
    </Grid>
</ContentPage>
// Copyright 2019 Esri.
//
// Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License.
// You may obtain a copy of the License at: http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific
// language governing permissions and limitations under the License.

using Esri.ArcGISRuntime.Geometry;
using Esri.ArcGISRuntime.Mapping;
using Esri.ArcGISRuntime.Ogc;
using Esri.ArcGISRuntime.UI;
using System;
using System.Collections.Generic;
using System.Globalization;
using System.IO;
using System.Linq;
using Xamarin.Forms;
using Color = System.Drawing.Color;
using Geometry = Esri.ArcGISRuntime.Geometry.Geometry;
#if __IOS__
using ArcGISRuntime.Samples.Managers;
#endif
#if __ANDROID__
using Android.Support.V4.Content;
using Android.Content.PM;
using Android;
#endif
#if WINDOWS_UWP
using Windows.Storage.Pickers;
#endif

namespace ArcGISRuntimeXamarin.Samples.CreateAndSaveKmlFile
{
    [ArcGISRuntime.Samples.Shared.Attributes.Sample(
        "Create and save KML file",
        "Layers",
        "Construct a KML document and save it as a KMZ file.",
        "",
        "Featured")]
    [ArcGISRuntime.Samples.Shared.Attributes.OfflineData()]
    public partial class CreateAndSaveKmlFile : ContentPage
    {
        private KmlDocument _kmlDocument;
        private KmlDataset _kmlDataset;
        private KmlLayer _kmlLayer;
        private KmlPlacemark _currentPlacemark;

        public CreateAndSaveKmlFile()
        {
            InitializeComponent();
            Initialize();
        }

        private void Initialize()
        {
            // Create the map.
            MyMapView.Map = new Map(Basemap.CreateImagery());

            List<String> colorHexes = new List<string>()
            {
                "#000000","#FFFFFF","#FF0000","#00FF00","#0000FF","#FFFF00", "#00FFFF","#FF00FF", "#C0C0C0", "#808080","#800000", "#808000","#008000", "#800080","#008080","#000080"
            };
            ColorPicker.ItemsSource = colorHexes;

            // Set the images for the point icon picker.
            List<string> iconLinks = new List<string>()
            {
                "https://static.arcgis.com/images/Symbols/Shapes/BlueCircleLargeB.png",
                "https://static.arcgis.com/images/Symbols/Shapes/BlueDiamondLargeB.png",
                "https://static.arcgis.com/images/Symbols/Shapes/BluePin1LargeB.png",
                "https://static.arcgis.com/images/Symbols/Shapes/BluePin2LargeB.png",
                "https://static.arcgis.com/images/Symbols/Shapes/BlueSquareLargeB.png",
                "https://static.arcgis.com/images/Symbols/Shapes/BlueStarLargeB.png"
            };
            List<Uri> iconList = iconLinks.Select(x => new Uri(x)).ToList();
            IconPicker.ItemsSource = iconLinks;

            // Set up a new kml document and kml layer.
            ResetKml();
        }
        private void ResetKml()
        {
            // Clear any existing layers from the map.
            MyMapView.Map.OperationalLayers.Clear();

            // Reset the most recently placed placemark.
            _currentPlacemark = null;

            // Create a new KML document.
            _kmlDocument = new KmlDocument() { Name = "KML Sample Document" };

            // Create a KML dataset using the KML document.
            _kmlDataset = new KmlDataset(_kmlDocument);

            // Create the KML layer using the KML dataset.
            _kmlLayer = new KmlLayer(_kmlDataset);

            // Add the KML layer to the map.
            MyMapView.Map.OperationalLayers.Add(_kmlLayer);
        }

        private async void Edit_Click(object sender, EventArgs e)
        {
            try
            {
                // Hide the base UI and enable the complete button.
                ShapeGrid.IsVisible = false;
                CompleteButton.IsVisible = true;
                SaveResetGrid.IsEnabled = false;

                // Create variables for the sketch creation mode and color.
                SketchCreationMode creationMode;

                // Set the creation mode and UI based on which button called this method.
                switch (((Button)sender).Text)
                {
                    case "Point":
                        creationMode = SketchCreationMode.Point;
                        Status.Text = "Tap to add a point.";
                        break;

                    case "Polyline":
                        creationMode = SketchCreationMode.Polyline;
                        Status.Text = "Tap to add a vertex.";
                        break;

                    case "Polygon":
                        creationMode = SketchCreationMode.Polygon;
                        Status.Text = "Tap to add a vertex.";
                        break;

                    default:
                        return;
                }

                // Get the user-drawn geometry.
                Geometry geometry = await MyMapView.SketchEditor.StartAsync(creationMode, true);

                // Project the geometry to WGS84 (WGS84 is required by the KML standard).
                Geometry projectedGeometry = GeometryEngine.Project(geometry, SpatialReferences.Wgs84);

                // Create a KmlGeometry using the new geometry.
                KmlGeometry kmlGeometry = new KmlGeometry(projectedGeometry, KmlAltitudeMode.ClampToGround);

                // Create a new placemark.
                _currentPlacemark = new KmlPlacemark(kmlGeometry);

                // Add the placemark to the KmlDocument.
                _kmlDocument.ChildNodes.Add(_currentPlacemark);

                // Choose whether to enable the icon picker or color picker.
                IconPicker.IsVisible = creationMode == SketchCreationMode.Point;
                ColorPicker.IsVisible = creationMode != SketchCreationMode.Point;

                // Enable the style editing UI.
                StyleUI.IsVisible = true;
                MainUI.IsVisible = false;
            }
            catch (ArgumentException)
            {
                await Application.Current.MainPage.DisplayAlert("Error", "Unsupported Geometry", "OK");
            }
            finally
            {
                // Reset the UI.
                ShapeGrid.IsVisible = true;
                CompleteButton.IsVisible = false;
                Status.Text = "Select the type of feature you would like to add.";

                // Enable the save and reset buttons.
                SaveResetGrid.IsEnabled = true;
            }
        }

        private void Apply_Style_Click(object sender, SelectedItemChangedEventArgs e)
        {
            // Get the color value if the selected item is a hexadecimal color.
            Color systemColor = Color.Transparent;
            if (((string)e.SelectedItem).StartsWith('#'))
            {
                Xamarin.Forms.Color platColor = Xamarin.Forms.Color.FromHex((string)e.SelectedItem);
                systemColor = Color.FromArgb((int)(platColor.A * 255), (int)(platColor.R * 255), (int)(platColor.G * 255), (int)(platColor.B * 255));
            }

            // Create a new style for the placemark.
            _currentPlacemark.Style = new KmlStyle();

            // Set the style for that Placemark.
            switch (_currentPlacemark.GraphicType)
            {
                // Create a KmlIconStyle using the selected icon.
                case KmlGraphicType.Point:
                    Uri iconLink = new Uri((string)e.SelectedItem);
                    _currentPlacemark.Style.IconStyle = new KmlIconStyle(new KmlIcon(iconLink), 1.0);
                    break;

                // Create a KmlLineStyle using the selected color value.
                case KmlGraphicType.Polyline:
                    _currentPlacemark.Style.LineStyle = new KmlLineStyle(systemColor, 8);
                    break;

                // Create a KmlPolygonStyle using the selected color value.
                case KmlGraphicType.Polygon:
                    _currentPlacemark.Style.PolygonStyle = new KmlPolygonStyle(systemColor);
                    _currentPlacemark.Style.PolygonStyle.IsFilled = true;
                    _currentPlacemark.Style.PolygonStyle.IsOutlined = false;
                    break;
            }

            // Reset the UI.
            MainUI.IsVisible = true;
            StyleUI.IsVisible = false;
        }

        private void No_Style_Click(object sender, EventArgs e)
        {
            // Reset the UI.
            StyleUI.IsVisible = false;
            MainUI.IsVisible = true;
        }

        private void Complete_Click(object sender, EventArgs e)
        {
            try
            {
                // Finish the sketch.
                MyMapView.SketchEditor.CompleteCommand.Execute(null);
            }
            catch (ArgumentException)
            {
            }
        }

        private async void Save_Click(object sender, EventArgs e)
        {
            try
            {
#if __IOS__
                // Determine the path for the file.
                string offlineDataFolder = Path.Combine(DataManager.GetDataFolder(), "CreateAndSaveKmlFile");

                // If temporary data folder doesn't exists, create it.
                if (!Directory.Exists(offlineDataFolder))
                {
                    Directory.CreateDirectory(offlineDataFolder);
                }

                string path = Path.Combine(offlineDataFolder, "sampledata.kmz");
                using (Stream stream = new FileStream(path, FileMode.OpenOrCreate, FileAccess.Write, FileShare.None))
                {
                    // Write the KML document to the stream of the file.
                    await _kmlDocument.WriteToAsync(stream);
                }
                await Application.Current.MainPage.DisplayAlert("Success", "KMZ file saved locally to ArcGISRuntimeSamples folder.", "OK");
#endif
#if __ANDROID__
                // Determine the path for the file.
                string filePath = Path.Combine(Android.OS.Environment.ExternalStorageDirectory.AbsolutePath, Android.OS.Environment.DirectoryDownloads, "sampledata.kmz");

                // Check if permission has not been granted.
                if(ContextCompat.CheckSelfPermission(Android.App.Application.Context, Manifest.Permission.WriteExternalStorage) != Permission.Granted)
                {
                    ArcGISRuntime.Droid.MainActivity.Instance.RequestPermissions(new[] { Manifest.Permission.WriteExternalStorage }, 1);
                }
                else
                {
                    using (Stream stream = new FileStream(filePath, FileMode.OpenOrCreate, FileAccess.Write, FileShare.None))
                    {
                        // Write the KML document to the stream of the file.
                        await _kmlDocument.WriteToAsync(stream);
                    }
                    await Application.Current.MainPage.DisplayAlert("Success", "File saved to " + filePath, "OK");
                }
#endif
#if WINDOWS_UWP
                // Open a save dialog for the user.
                FileSavePicker savePicker = new FileSavePicker();
                savePicker.SuggestedStartLocation = PickerLocationId.DocumentsLibrary;
                savePicker.FileTypeChoices.Add("KMZ file", new List<string>() { ".kmz" });
                Windows.Storage.StorageFile file = await savePicker.PickSaveFileAsync();

                if (file != null)
                {
                    using (Stream stream = await file.OpenStreamForWriteAsync())
                    {
                        // Write the KML document to the stream of the file.
                        await _kmlDocument.WriteToAsync(stream);
                    }
                }
#endif
            }
            catch (Exception)
            {
                await Application.Current.MainPage.DisplayAlert("Error", "File not saved.", "OK");
            }
        }

        private void Reset_Click(object sender, EventArgs e)
        {
            ResetKml();
        }
    }
    internal class ImageConverter : IValueConverter
    {
        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            if (value == null || value.GetType() != typeof(string)) { return null; }
            return ImageSource.FromUri(new Uri((string)value));
        }

        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
        {
            throw new NotImplementedException();
        }
    }
    internal class ColorConverter : IValueConverter
    {
        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            if (value == null || value.GetType() != typeof(string)) { return null; }
            return Xamarin.Forms.Color.FromHex((string)value);
        }

        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
        {
            throw new NotImplementedException();
        }
    }
}