using System;

using System.Drawing;

using System.Web;

using System.Web.UI;

using SharpMap;

using SharpMap.Data;

using SharpMap.Layers;

using SharpMap.Rendering.Thematics;

using SharpMap.Styles;

using SharpMap.Web;

using Point=GeoAPI.Geometries.Coordinate;

public partial class Bins : Page

{

private static readonly Random rand = new Random();

private Map myMap;

protected void Page_Load(object sender, EventArgs e)

{

//Set up the map. We use the method in the App_Code folder for initializing the map and alter it afterwards

myMap = MapHelper.InitializeMap(new Size((int) imgMap.Width.Value, (int) imgMap.Height.Value));

//Remove the river layer and label-layers

myMap.Layers.RemoveAt(4);

myMap.Layers.RemoveAt(3);

myMap.Layers.RemoveAt(1);

//Create Pie Layer

VectorLayer pieLayer = new VectorLayer("Pie charts");

pieLayer.DataSource = (myMap.Layers[0] as VectorLayer).DataSource;

CustomTheme iTheme = new CustomTheme(GetCountryStyle);

pieLayer.Theme = iTheme;

myMap.Layers.Add(pieLayer);

if (Page.IsPostBack)

{

//Page is post back. Restore center and zoom-values from viewstate

myMap.Center = (Point) ViewState["mapCenter"];

myMap.Zoom = (double) ViewState["mapZoom"];

}

else

{

//This is the initial view of the map. Zoom to the extents of the map:

//myMap.ZoomToExtents();

myMap.Center = new Point(10, 50);

myMap.Zoom = 60;

//Create the map

GenerateMap();

}

}

/// <summary>

/// This method is used for determining the style

/// It is used as a delegate for the CustomTheme class.

/// </summary>

/// <param name="row"></param>

/// <returns></returns>

private VectorStyle GetCountryStyle(FeatureDataRow row)

{

VectorStyle s = new VectorStyle();

s.Fill = new SolidBrush(Color.Green);

s.Symbol = GetPieChart(row);

return s;

}

/// <summary>

/// Method for creating pie chart symbols

/// </summary>

/// <remarks>

/// <para>In this example we just create some random pie charts,

/// but it probably should be based on attributes read from the row.</para>

/// <para>Credits goes to gonzalo_ar for posting this in the forum</para></remarks>

/// <param name="row"></param>

/// <returns></returns>

private static Bitmap GetPieChart(FeatureDataRow row)

{

// Replace polygon with a center point (this is where we place the symbol

row.Geometry = row.Geometry.Centroid;

// Just for the example I use random values

int size = rand.Next(20, 35);

int angle1 = rand.Next(60, 180);

int angle2 = rand.Next(angle1 + 60, 300);

Rectangle rect = new Rectangle(0, 0, size, size);

Bitmap b = new Bitmap(size, size);

using (var g = Graphics.FromImage(b))

{

// Draw Pie

g.FillPie(Brushes.LightGreen, rect, 0, angle1);

g.FillPie(Brushes.Pink, rect, angle1, angle2 - angle1);

g.FillPie(Brushes.PeachPuff, rect, angle2, 360 - angle2);

// Draw Borders

g.DrawPie(Pens.Green, rect, 0, angle1);

g.DrawPie(Pens.Red, rect, angle1, angle2 - angle1);

g.DrawPie(Pens.Orange, rect, angle2, 360 - angle2);

}

return b;

}

protected void imgMap_Click(object sender, ImageClickEventArgs e)

{

//Set center of the map to where the client clicked

myMap.Center = myMap.ImageToWorld(new System.Drawing.Point(e.X, e.Y));

//Set zoom value if any of the zoom tools were selected

if (rblMapTools.SelectedValue == "0") //Zoom in

myMap.Zoom = myMap.Zoom*0.5;

else if (rblMapTools.SelectedValue == "1") //Zoom out

myMap.Zoom = myMap.Zoom*2;

//Create the map

GenerateMap();

}

/// <summary>

/// Creates the map, inserts it into the cache and sets the ImageButton Url

/// </summary>

private void GenerateMap()

{

//Save the current mapcenter and zoom in the viewstate

ViewState.Add("mapCenter", myMap.Center);

ViewState.Add("mapZoom", myMap.Zoom);

Image img = myMap.GetMap();

string imgID = Caching.InsertIntoCache(1, img);

imgMap.ImageUrl = "getmap.aspx?ID=" + HttpUtility.UrlEncode(imgID);

}

}