Create and save KML file

<UserControl x:Class="ArcGIS.WinUI.Samples.CreateAndSaveKmlFile.CreateAndSaveKmlFile"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:esriUI="using:Esri.ArcGISRuntime.UI.Controls">
    <Grid>
        <esriUI:MapView x:Name="MyMapView" />
        <Border Name="MainUI" Style="{StaticResource BorderStyle}">
            <Grid>
                <Grid.RowDefinitions>
                    <RowDefinition Height="auto" />
                    <RowDefinition Height="auto" />
                    <RowDefinition Height="auto" />
                </Grid.RowDefinitions>
                <TextBlock Name="InstructionsText"
                           Margin="5"
                           HorizontalAlignment="Center"
                           VerticalAlignment="Center"
                           Text="Select the type of feature you would like to add." />
                <Grid Grid.Row="1">
                    <Grid Name="ShapesPanel">
                        <Grid.ColumnDefinitions>
                            <ColumnDefinition Width="*" />
                            <ColumnDefinition Width="*" />
                            <ColumnDefinition Width="*" />
                        </Grid.ColumnDefinitions>
                        <Button x:Name="PointButton"
                                Grid.Column="0"
                                Margin="5"
                                HorizontalAlignment="Stretch"
                                Click="Edit_Click"
                                Content="Point" />
                        <Button x:Name="PolylineButton"
                                Grid.Column="1"
                                Margin="5"
                                HorizontalAlignment="Stretch"
                                Click="Edit_Click"
                                Content="Polyline" />
                        <Button x:Name="PolygonButton"
                                Grid.Column="2"
                                Margin="5"
                                HorizontalAlignment="Stretch"
                                Click="Edit_Click"
                                Content="Polygon" />
                    </Grid>
                </Grid>
                <Grid x:Name="SaveResetGrid" Grid.Row="2">
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width="*" />
                        <ColumnDefinition Width="*" />
                    </Grid.ColumnDefinitions>
                    <Button Grid.Column="0"
                            Margin="5"
                            HorizontalAlignment="Stretch"
                            Click="Save_Click"
                            Content="Save KMZ file" />
                    <Button Grid.Column="1"
                            Margin="5"
                            HorizontalAlignment="Stretch"
                            Click="Reset_Click"
                            Content="Reset" />
                </Grid>
                <Button x:Name="CompleteButton"
                        Grid.Row="1"
                        Margin="5"
                        HorizontalAlignment="Stretch"
                        Click="Complete_Click"
                        Content="Complete Sketch"
                        Visibility="Collapsed" />
            </Grid>
        </Border>
        <Border x:Name="StyleBorder"
                Width="auto"
                HorizontalAlignment="Right"
                VerticalAlignment="Center"
                Style="{StaticResource BorderStyle}"
                Visibility="Collapsed">
            <Grid>
                <Grid.RowDefinitions>
                    <RowDefinition />
                    <RowDefinition Height="auto" />
                    <RowDefinition />
                </Grid.RowDefinitions>
                <Grid.ColumnDefinitions>
                    <ColumnDefinition />
                    <ColumnDefinition />
                </Grid.ColumnDefinitions>
                <TextBlock x:Name="StyleText"
                           Grid.Row="0"
                           Grid.ColumnSpan="2"
                           Margin="5"
                           Text="" />
                <ComboBox x:Name="IconPicker"
                          Grid.Row="1"
                          Grid.ColumnSpan="2"
                          Height="40"
                          Margin="5"
                          HorizontalAlignment="Center"
                          ItemsSource="{Binding}">
                    <ComboBox.ItemTemplate>
                        <DataTemplate>
                            <BitmapIcon Width="30"
                                        Height="30"
                                        ShowAsMonochrome="False"
                                        UriSource="{Binding}" />
                        </DataTemplate>
                    </ComboBox.ItemTemplate>
                </ComboBox>
                <ColorPicker x:Name="ColorSelector"
                             Grid.Row="1"
                             Grid.ColumnSpan="2"
                             ColorSpectrumShape="Box"
                             IsAlphaSliderVisible="False"
                             IsColorChannelTextInputVisible="False"
                             IsColorPreviewVisible="False"
                             IsColorSliderVisible="False"
                             IsHexInputVisible="False" />
                <Button Grid.Row="2"
                        Grid.Column="0"
                        Margin="5"
                        HorizontalAlignment="Stretch"
                        Click="Apply_Style_Click"
                        Content="Apply Style" />
                <Button Grid.Row="2"
                        Grid.Column="1"
                        Margin="5"
                        HorizontalAlignment="Stretch"
                        Click="No_Style_Click"
                        Content="Don't Apply Style" />
            </Grid>
        </Border>
    </Grid>
</UserControl>

// 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 ArcGIS.WinUI.Viewer;
using Esri.ArcGISRuntime.Geometry;
using Esri.ArcGISRuntime.Mapping;
using Esri.ArcGISRuntime.Ogc;
using Microsoft.UI.Xaml;
using Microsoft.UI.Xaml.Controls;
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Drawing;
using System.IO;
using System.Linq;
using Windows.Storage.Pickers;
using Geometry = Esri.ArcGISRuntime.Geometry.Geometry;

namespace ArcGIS.WinUI.Samples.CreateAndSaveKmlFile
{
    [ArcGIS.Samples.Shared.Attributes.Sample(
        name: "Create and save KML file",
        category: "Layers",
        description: "Construct a KML document and save it as a KMZ file.",
        instructions: "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.",
        tags: new[] { "KML", "KMZ", "Keyhole", "OGC", "geometry editor" })]
    [ArcGIS.Samples.Shared.Attributes.OfflineData()]
    public partial class CreateAndSaveKmlFile
    {
        private KmlDocument _kmlDocument;
        private KmlDataset _kmlDataset;
        private KmlLayer _kmlLayer;
        private KmlPlacemark _currentPlacemark;
        private GeometryType _geometryType;

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

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

            // 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 = _iconList;
            IconPicker.SelectedIndex = 0;

            // 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, RoutedEventArgs e)
        {
            try
            {
                // Hide the base UI and enable the complete button.
                ShapesPanel.Visibility = Visibility.Collapsed;
                CompleteButton.Visibility = Visibility.Visible;
                SaveResetGrid.Visibility = Visibility.Collapsed;

                // Set the creation mode and UI based on which button called this method.
                switch (((Button)sender).Name)
                {
                    case nameof(PointButton):
                        _geometryType = GeometryType.Point;
                        InstructionsText.Text = "Tap to add a point.";
                        StyleText.Text = "Select an icon for the placemark.";
                        break;

                    case nameof(PolylineButton):
                        _geometryType = GeometryType.Polyline;
                        InstructionsText.Text = "Tap to add a vertex.";
                        StyleText.Text = "Select a color for the placemark.";
                        break;

                    case nameof(PolygonButton):
                        _geometryType = GeometryType.Polygon;
                        InstructionsText.Text = "Tap to add a vertex.";
                        StyleText.Text = "Select a color for the placemark.";
                        break;

                    default:
                        return;
                }

                // Start the geometry editor.
                MyMapView.GeometryEditor.Start(_geometryType);

            }
            catch (ArgumentException)
            {
                await new MessageDialog2("Unsupported Geometry", "Error").ShowAsync();
            }
        }

        private void Apply_Style_Click(object sender, RoutedEventArgs e)
        {
            // Create a new style for the placemark.
            _currentPlacemark.Style = new KmlStyle();

            // Get the color from the ColorSelector
            var selected = ColorSelector.Color;
            Color color = Color.FromArgb(selected.A, selected.R, selected.G, selected.B);

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

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

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

            // Reset the UI.
            StyleBorder.Visibility = Visibility.Collapsed;
            MainUI.Visibility = Visibility.Visible;
        }

        private void No_Style_Click(object sender, RoutedEventArgs e)
        {
            // Reset the UI.
            StyleBorder.Visibility = Visibility.Collapsed;
            MainUI.Visibility = Visibility.Visible;
        }

        private void Complete_Click(object sender, RoutedEventArgs e)
        {
            try
            {
                // Get the user-drawn geometry.
                Geometry geometry = MyMapView.GeometryEditor.Stop();

                // Hold a reference for the new placemark geometry.
                KmlGeometry kmlGeometry;

                // Check to see if a geometry has been drawn.
                if (!geometry.IsEmpty)
                {

                    if (MyMapView.SpatialReference != null &&
                        geometry.SpatialReference != MyMapView.SpatialReference)
                    {
                        // Project the geometry to WGS84 (WGS84 is required by the KML standard).
                        Geometry projectedGeometry = geometry.Project(SpatialReferences.Wgs84);

                        // Create a KmlGeometry using the projected geometry.
                        kmlGeometry = new KmlGeometry(projectedGeometry, KmlAltitudeMode.ClampToGround);
                    }
                    else
                    {
                        // Create a KmlGeometry using the user-drawn geometry.
                        kmlGeometry = new KmlGeometry(geometry, KmlAltitudeMode.ClampToGround);
                    }

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

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

                    // Enable the style editing UI.
                    StyleBorder.Visibility = Visibility.Visible;
                    MainUI.Visibility = Visibility.Collapsed;

                    // Display the Icon picker or the color picker based on the creation mode.
                    IconPicker.Visibility = _geometryType == GeometryType.Point ? Visibility.Visible : Visibility.Collapsed;
                    ColorSelector.Visibility = _geometryType != GeometryType.Point ? Visibility.Visible : Visibility.Collapsed;
                }
            }
            catch (Exception ex)
            {
                Debug.WriteLine(ex.Message);
            }
            finally
            {
                // Reset the UI.
                ShapesPanel.Visibility = Visibility.Visible;
                CompleteButton.Visibility = Visibility.Collapsed;
                InstructionsText.Text = "Select the type of feature you would like to add.";

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

        private async void Save_Click(object sender, RoutedEventArgs e)
        {
            try
            {
                // Open a save dialog for the user.
                FileSavePicker savePicker = new FileSavePicker();
                WinRT.Interop.InitializeWithWindow.Initialize(savePicker, App.CurrentWindowHandle);
                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);
                    }
                    await new MessageDialog2("Item saved.").ShowAsync();
                }
            }
            catch
            {
                await new MessageDialog2("File not saved.").ShowAsync();
            }
        }

        private void Reset_Click(object sender, RoutedEventArgs e)
        {
            ResetKml();
        }
    }
}