SortLayers.cs

This example demonstrates how to sorts layers by the type of shapefile (first polygons, the polylines and finally points) and alphabetically. Here is a screenshot with the results of the code.

using System;
using System.Windows.Forms;
using AxMapWinGIS;
using MapWinGIS;
using System.IO;
using System.Collections.Generic;

public partial class MapExamples
{
    // <summary>
    // This code sorts layers added to the map alphabetically.
    // </summary>
    public  void SortLayers(AxMap axMap1, string dataPath)
    {
        if (this.AddLayersFromPath(axMap1, dataPath))
        {
            this.LayersInfo();

            this.SortLayersByType();

            this.ShowLayerNames("Sorted by type: " + Environment.NewLine);

            this.SortAlphabetically();

            this.ShowLayerNames("Sorted alphabetically: " + Environment.NewLine);
        }
    }

    // <summary>
    // Sorts layers alphabetically
    // </summary>
    private void SortAlphabetically()
    {
        int[] handles = new int[axMap1.NumLayers];
        string[] names = new string[axMap1.NumLayers];

        for (int i = 0; i < axMap1.NumLayers; i++)
        {
            int layerHandle = axMap1.get_LayerHandle(i);
            handles[i] = layerHandle;
            names[i] = axMap1.get_LayerName(layerHandle);
        }

        Array.Sort(names, handles);

        axMap1.LockWindow(tkLockMode.lmLock);
        try
        {
            foreach (int handle in handles)
            {
                int position = axMap1.get_LayerPosition(handle);
                axMap1.MoveLayerBottom(position);
            }
        }
        finally
        {
            axMap1.LockWindow(tkLockMode.lmUnlock);
        }
    }

    // <summary>
    // Sorts shapefiles by type: polygons - polyline - points 
    // </summary>
    public void SortLayersByType()
    {
        for (int j = 0; j < 3; j++)
        {
            List<int> handles = new List<int>();

            for (int i = 0; i < axMap1.NumLayers; i++)
            {
                int layerHandle = axMap1.get_LayerHandle(i);
                Shapefile sf = axMap1.get_Shapefile(layerHandle);
                if (sf != null)
                {
                    if (j == 0 && sf.ShapefileType == ShpfileType.SHP_POINT)
                        handles.Add(layerHandle);

                    if (j == 1 && sf.ShapefileType == ShpfileType.SHP_POLYLINE)
                        handles.Add(layerHandle);

                    if (j == 2 && sf.ShapefileType == ShpfileType.SHP_POLYGON)
                        handles.Add(layerHandle);
                }
            }

            axMap1.LockWindow(tkLockMode.lmLock);
            try
            {
                foreach (int handle in handles)
                {
                    int position = axMap1.get_LayerPosition(handle);
                    axMap1.MoveLayerBottom(position);
                }
            }
            finally
            {
                axMap1.LockWindow(tkLockMode.lmUnlock);
            }
        }
    }

    // <summary>
    // Displays names of the layers
    // </summary>
    private void ShowLayerNames(string description)
    {
        string message = "";
        for (int i = axMap1.NumLayers - 1; i >= 0 ; i--)
        {
            int layerHandle = axMap1.get_LayerHandle(i);
            string name = axMap1.get_LayerName(layerHandle);
            object layer = axMap1.get_GetObject(layerHandle);
            string type = string.Empty;
            if (layer as Shapefile != null)
            {
                type = (layer as Shapefile).ShapefileType.ToString();
            }
            else{
                type = "Image";
            }

            message += name + ": " + type + Environment.NewLine;
        }
        MessageBox.Show(description + message);
    }

    // <summary>
    // Reports the number of the layers by type added to the map.
    // </summary>
    public void LayersInfo()
    {
        int pointCount = 0;
        int lineCount = 0;
        int polyCount = 0;
        int imgCount = 0;

        for (int i = 0; i < axMap1.NumLayers; i++)
        {
            object layer = axMap1.get_GetObject(axMap1.get_LayerHandle(i));
            Shapefile sf = layer as Shapefile;
            if (sf != null)
            {
                switch (sf.ShapefileType)
                {
                    case ShpfileType.SHP_POINT:
                        pointCount++;
                        break;
                    case ShpfileType.SHP_POLYLINE:
                        lineCount++;
                        break;
                    case ShpfileType.SHP_POLYGON:
                        polyCount++;
                        break;
                }
            }
            else
            {
                Image img = layer as Image;
                if (img != null)
                {
                    imgCount++;
                }
            }
        }

        string s = string.Format("Layers added to the map:" + Environment.NewLine +
                                 "Point shapefiles: {0}" + Environment.NewLine +
                                 "Polyline shapefiles: {0}" + Environment.NewLine +
                                 "Polygon shapefiles: {0}" + Environment.NewLine +
                                 "Images: {3}", pointCount, lineCount, polyCount, imgCount);
        MessageBox.Show(s);
    }
}