Adding a layer/Removing a layer - C#
Ian Erickson
ierickson at ANALYGIS.COM
Tue Apr 4 18:56:29 EDT 2006
Can anyone point me to an example of using MapScript C# that:
a) Loads a map
b) Adds 2 or 3 *dynamic* layers, classes, and styles
c) Disposes of the map and associated layers properly.
I've got an example working here - but when more than 1 layerObj is
created and added to the map, I get a bunch of
mapscriptPINVOKE.delete_classObj or .delete_layerObj errors. Obviously,
things are happening in the SWIG interface - like disposing of objects -
but it doesn't appear to be working properly.
I've attached some sample C# code - perhaps someone can immediately
identify my error...
//-------------------------------------------------------------------------------------------------------
using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
namespace MapScriptMap
{
/// <summary>
/// Summary description for MapServerForm.
/// </summary>
public class MapServerForm : System.Windows.Forms.Form
{
private System.Windows.Forms.PictureBox MapImage;
/// <summary>
/// Required designer variable.
/// </summary>
private System.ComponentModel.Container components = null;
private System.Windows.Forms.Button buttonCreatePointLayer;
private mapObj msMap = null;
private System.Windows.Forms.Button buttonCreateLineLayer;
private ArrayList layerIndex = null;
public MapServerForm()
{
//
// Required for Windows Form Designer support
//
InitializeComponent();
InitializeMap();
}
private void InitializeMap()
{
try
{
this.msMap = new mapObj(@"C:\data\base.map");
this.layerIndex = new ArrayList(0);
}
catch (Exception e)
{
Console.WriteLine(e.StackTrace);
this.msMap = null;
}
}
private void CreatePointLayer(string layerName)
{
this.CreatePointLayer(layerName, 7,
System.Drawing.Color.FromArgb(0, 192, 0));
}
private void CreatePointLayer(string layerName, int symbolSize,
System.Drawing.Color color)
{
if (this.layerExists(layerName))
return;
layerObj pointLayer = new layerObj(this.msMap);
pointLayer.name = layerName;
pointLayer.type = MS_LAYER_TYPE.MS_LAYER_POINT;
pointLayer.setProjection("init=epsg:4326");
pointLayer.status = 1;
classObj pointClass = new classObj(pointLayer);
pointClass.label.type = MS_FONT_TYPE.MS_TRUETYPE;
pointClass.label.font = "arial-bold";
pointClass.label.size = 7;
pointClass.label.color.setRGB(0,0,0);
pointClass.label.position = 2;
styleObj pointStyle = new styleObj(pointClass);
pointStyle.symbol = 7;
pointStyle.antialias = 1;
pointStyle.size = symbolSize;
pointStyle.color.setRGB((int)color.R,(int)color.G,(int)color.B);
pointStyle.outlinecolor.setRGB((int)(color.R /
2),(int)(color.G / 2),(int)(color.B / 2));
Console.WriteLine("Point layer: " + layerName + " added to
the map...");
this.layerIndex.Add(layerName);
}
private void CreateLineLayer(string layerName)
{
if (this.layerExists(layerName))
return;
layerObj lineLayer = new layerObj(this.msMap);
lineLayer.name = layerName;
lineLayer.type = MS_LAYER_TYPE.MS_LAYER_LINE;
lineLayer.setProjection("init=epsg:4326");
lineLayer.transparency = 30;
lineLayer.status = 1;
classObj lineClass = new classObj(lineLayer);
lineClass.label.type = MS_FONT_TYPE.MS_TRUETYPE;
lineClass.label.font = "arial-bold";
lineClass.label.size = 7;
lineClass.label.color.setRGB(0,0,0);
lineClass.label.position = 2;
styleObj lineStyle = new styleObj(lineClass);
lineStyle.symbol = 7;
lineStyle.size = 8;
lineStyle.color.setRGB(192,0,192);
Console.WriteLine("Line layer: " + layerName + " added to
the map...");
this.layerIndex.Add(layerName);
}
private bool layerExists(string layerName)
{
if (this.msMap == null)
return false;
for (int i = 0; i < this.msMap.numlayers; i++)
{
if (this.msMap.getLayer(i).name.ToUpper() ==
layerName.ToUpper())
return true;
}
return false;
}
private void RemoveLayers()
{
foreach(string layerName in this.layerIndex)
{
layerObj l = this.msMap.getLayerByName(layerName);
// while (l.numclasses > 0)
// {
// classObj c = l.getClass(0);
// l.removeClass(0);
// c.Dispose();
// }
this.msMap.removeLayer(l.index);
l.Dispose();
}
this.layerIndex.Clear();
}
private void RenderMap()
{
if (this.msMap == null)
return;
msMap.setSize(this.MapImage.Width, this.MapImage.Height);
imageObj msImage;
try
{
msImage = msMap.draw();
System.IO.MemoryStream ms = new
System.IO.MemoryStream(msImage.getBytes());
Bitmap img = new Bitmap(ms);
this.MapImage.Image = img;
}
catch (Exception e)
{
Console.WriteLine(e.StackTrace);
}
}
/// <summary>
/// Clean up any resources being used.
/// </summary>
protected override void Dispose( bool disposing )
{
if( disposing )
{
if (components != null)
{
components.Dispose();
}
}
base.Dispose( disposing );
}
#region Windows Form Designer generated code
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
this.MapImage = new System.Windows.Forms.PictureBox();
this.buttonCreatePointLayer = new System.Windows.Forms.Button();
this.buttonCreateLineLayer = new System.Windows.Forms.Button();
this.SuspendLayout();
//
// MapImage
//
this.MapImage.BorderStyle =
System.Windows.Forms.BorderStyle.Fixed3D;
this.MapImage.Location = new System.Drawing.Point(8, 8);
this.MapImage.Name = "MapImage";
this.MapImage.Size = new System.Drawing.Size(272, 248);
this.MapImage.TabIndex = 0;
this.MapImage.TabStop = false;
//
// buttonCreatePointLayer
//
this.buttonCreatePointLayer.Location = new
System.Drawing.Point(288, 8);
this.buttonCreatePointLayer.Name = "buttonCreatePointLayer";
this.buttonCreatePointLayer.Size = new
System.Drawing.Size(176, 23);
this.buttonCreatePointLayer.TabIndex = 1;
this.buttonCreatePointLayer.Text = "Create Point Layer";
this.buttonCreatePointLayer.Click += new
System.EventHandler(this.buttonCreatePointLayer_Click);
//
// buttonCreateLineLayer
//
this.buttonCreateLineLayer.Location = new
System.Drawing.Point(288, 40);
this.buttonCreateLineLayer.Name = "buttonCreateLineLayer";
this.buttonCreateLineLayer.Size = new
System.Drawing.Size(176, 23);
this.buttonCreateLineLayer.TabIndex = 2;
this.buttonCreateLineLayer.Text = "Create Line Layer";
this.buttonCreateLineLayer.Click += new
System.EventHandler(this.buttonCreateLineLayer_Click);
//
// MapServerForm
//
this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
this.ClientSize = new System.Drawing.Size(472, 302);
this.Controls.Add(this.buttonCreateLineLayer);
this.Controls.Add(this.buttonCreatePointLayer);
this.Controls.Add(this.MapImage);
this.Name = "MapServerForm";
this.Text = "MapServer Map";
this.Closing += new
System.ComponentModel.CancelEventHandler(this.MapServerForm_Closing);
this.Load += new System.EventHandler(this.MapServerForm_Load);
this.ResumeLayout(false);
}
#endregion
/// <summary>
/// The main entry point for the application.
/// </summary>
[STAThread]
static void Main()
{
Application.Run(new MapServerForm());
}
private void MapServerForm_Load(object sender, System.EventArgs e)
{
this.RenderMap();
}
private void buttonCreatePointLayer_Click(object sender,
System.EventArgs e)
{
this.CreatePointLayer("BLAH", 10,
System.Drawing.Color.FromArgb(192, 0, 0));
this.RenderMap();
}
private void buttonCreateLineLayer_Click(object sender,
System.EventArgs e)
{
this.CreateLineLayer("LINE");
this.RenderMap();
}
private void MapServerForm_Closing(object sender,
System.ComponentModel.CancelEventArgs e)
{
// this.RemoveLayers();
// if (this.msMap != null)
// this.msMap.Dispose();
//
// this.msMap = null;
}
}
}
--
Ian Erickson
AnalyGIS, LLC
Gold Canyon, AZ 85218
http:// www.analygis.com
tel: 480.677.6260
mob: 480.221.7173
fax: 480.677.6261
See AnalyGIS at work:
http://65.39.85.13/google/
http://65.39.85.13/virtualearth/
More information about the mapserver-users
mailing list