using System;
using ThinkGeo.MapSuite.Core;
using ThinkGeo.MapSuite.DesktopEdition;
namespace DrawCustomException
{
    // We inherit from the exisitng overlay to create a new one that helps us simulate
    // going on and offline and drawing a custom exception.  If you used this in production
    // you would only need to override the DrawExceptionCore method and set the this.DrawExceptionMode
    // The rest of the code in this class is just used to simulate going on and offline and
    // showing you the difference between the default drawing and custom drawing of an exception
    public class CustomWorldMapKitWmsDesktopOverlay : WorldMapKitWmsDesktopOverlay
    {
        private bool drawCustomException;
        private bool online;
        // In this public constructor we set the drawing exception mode.
        public CustomWorldMapKitWmsDesktopOverlay()
            : base()
        {
            this.DrawingExceptionMode = DrawingExceptionMode.DrawException;
            drawCustomException = false;
            online = true;
        }
        // This property is just fir us to simulate switching
        // bewtween custom and standard exception drawing
        public bool DrawCustomException
        {
            get { return drawCustomException; }
            set { drawCustomException = value; }
        }
        // This just simulates being on and offline by throwing
        // an error if you are offline
        public bool Online
        {
            get { return online; }
            set { online = value; }
        }
        // This code is just here to simulate being on and offline
        protected override void DrawCore(GeoCanvas canvas)
        {
            if (online)
            {
                base.DrawCore(canvas);
            }
            else
            {
                throw new Exception("Unable to connect to the WMS server.");
            }
        }
        // Here we override the DrawException method and do our own drawing of the exception.
        // We use the drawCustomException only for the sample
        protected override void DrawExceptionCore(GeoCanvas canvas, Exception e)
        {
            if (drawCustomException)
            {
                // We are writing directly to the canvas.  Note that above we have access to the exception itself
                // and we could make the image based on that.
                canvas.DrawTextWithScreenCoordinate(e.Message, new GeoFont("Arial", 20), new GeoSolidBrush(new GeoColor(120, GeoColor.StandardColors.Red)), canvas.Width / 2, canvas.Height / 2, DrawingLevel.LevelOne);
            }
            else
            {
                base.DrawExceptionCore(canvas, e);
            }
        }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows.Forms;
namespace DrawCustomException
{
    static class Program
    {
        /// <summary>
        /// The main entry point for the application.
        /// </summary>
        [STAThread]
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            Application.Run(new TestForm());
        }
    }
}

using System;
using System.Diagnostics;
using System.Windows.Forms;
using ThinkGeo.MapSuite.Core;
namespace DrawCustomException
{
    public partial class TestForm : Form
    {
        public TestForm()
        {
            InitializeComponent();
            // This is a warning to let people know the sample will not run properly if the debugger is attached.
            if (Debugger.IsAttached)
            {
                MessageBox.Show("For this sample to work properly you need to run it without the debugger attached.  You can use Ctrl-F5 or in the debug menu choose 'Start Without Debugging.'");
            }
        }
        private void TestForm_Load(object sender, EventArgs e)
        {
            // Set the full extent and the background color
            winformsMap1.CurrentExtent = new RectangleShape(-124.89,49.36,-66.79,20.01);
            winformsMap1.BackgroundOverlay.BackgroundBrush = new GeoSolidBrush(GeoColor.GeographicColors.ShallowOcean);
            CustomWorldMapKitWmsDesktopOverlay worldMapKitDesktopOverlay = new CustomWorldMapKitWmsDesktopOverlay();
            winformsMap1.Overlays.Add("WorldOverlay",worldMapKitDesktopOverlay);
            // Draw the map image on the screen
            winformsMap1.Refresh();
        }
        // If the user changes the status we change the online property in the overlay.  Note this is just
        // to simulate going on or offline.  If this were not a sample this code would not be necessary
        private void rbnOnline_CheckedChanged(object sender, EventArgs e)
        {
            ((CustomWorldMapKitWmsDesktopOverlay)winformsMap1.Overlays["WorldOverlay"]).Online = rbnOnline.Checked;
            winformsMap1.Refresh();
        }
        // If the user changes the status we change the drawing exception mode of the overlay.  Note this is just
        // to show different options.  If this were not a sample this code would not be necessary.  You would just
        // set the one mode you want and leave it.
        private void rbnException_CheckedChanged(object sender, EventArgs e)
        {
            // In this case we want to throw the exception
            if (rbnThrowException.Checked)
            {
                ((CustomWorldMapKitWmsDesktopOverlay)winformsMap1.Overlays["WorldOverlay"]).DrawingExceptionMode = DrawingExceptionMode.ThrowException;
            }
            // In this case we want to draw the excpetion using the deault drawing we provide in the overlay
            if (rbnDrawException.Checked)
            {
                ((CustomWorldMapKitWmsDesktopOverlay)winformsMap1.Overlays["WorldOverlay"]).DrawingExceptionMode = DrawingExceptionMode.DrawException;
                ((CustomWorldMapKitWmsDesktopOverlay)winformsMap1.Overlays["WorldOverlay"]).DrawCustomException = false;
            }
            // In this case we want to do our own custom exception drawing
            if (rbnDrawCustomException.Checked)
            {
                ((CustomWorldMapKitWmsDesktopOverlay)winformsMap1.Overlays["WorldOverlay"]).DrawingExceptionMode = DrawingExceptionMode.DrawException;
                ((CustomWorldMapKitWmsDesktopOverlay)winformsMap1.Overlays["WorldOverlay"]).DrawCustomException = true;
            }
            winformsMap1.Refresh();
        }
        private void btnClose_Click(object sender, EventArgs e)
        {
            this.Close();
        }
        private void winformsMap1_MouseMove(object sender, MouseEventArgs e)
        {
            //Displays the X and Y in screen coordinates.
            statusStrip1.Items["toolStripStatusLabelScreen"].Text = "X:" + e.X + " Y:" + e.Y;
            //Gets the PointShape in world coordinates from screen coordinates.
            PointShape pointShape = ExtentHelper.ToWorldCoordinate(winformsMap1.CurrentExtent, new ScreenPointF(e.X, e.Y), winformsMap1.Width, winformsMap1.Height);
            //Displays world coordinates.
            statusStrip1.Items["toolStripStatusLabelWorld"].Text = "(world) X:" + Math.Round(pointShape.X, 4) + " Y:" + Math.Round(pointShape.Y, 4);
        }
    }
}