Highlighting features with ArcGis Server 9.2

I have the need to highlight items when the user selects to zoom to a particular item from a custom search. If I was using the ResultsTask control, then the user could simply check the checkbox next to the feature, and it would highlight. However, since the client doesn't like the treeview style of the ResultsTask, I have put the search results into an HTML table. Now, when the user selects to zoom to a feature, it will automatically highlight the feature.

I found this code in the ESRI forums, and it works well.

// This gives us a nice light blue color. You can change the color to whatever you want.
ESRI.ArcGIS.ADF.ArcGISServer.RgbColor irgbc = new ESRI.ArcGIS.ADF.ArcGISServer.RgbColor();
irgbc.Red = 50;
irgbc.Green = 255;
irgbc.Blue = 255;
irgbc.AlphaValue = 255;

ESRI.ArcGIS.ADF.ArcGISServer.FIDSet fids = new ESRI.ArcGIS.ADF.ArcGISServer.FIDSet();
int[] ids = new int[1];
ids[0] = Convert.ToInt32(key); //<-- OBJECTID of the feature to highlight
fids.FIDArray = ids;

ESRI.ArcGIS.ADF.ArcGISServer.MapDescription mapdesc = ((MapFunctionality)mf).MapDescription;
ESRI.ArcGIS.ADF.ArcGISServer.LayerDescription[] layerdescs = mapdesc.LayerDescriptions;
ESRI.ArcGIS.ADF.ArcGISServer.LayerDescription layerdesc = layerdescs[layerid];
layerdesc.Visible = true;
layerdesc.SelectionColor = irgbc;
layerdesc.SelectionFeatures = fids.FIDArray;

The problem with the above code is that it highlights the entire area. Not bad for point features, but for polygons, it covers everything underneath it completely. I tried adjusting the RgbColor.AlphaValue, but that didn't change anything at all. I'm thinking that is a red herring, and doesn't really do anything at all. So what I decided to do was instead of filling the entire polygon, I just use ShowSelectBuffer as seen below:

ESRI.ArcGIS.ADF.ArcGISServer.RgbColor irgbc = new ESRI.ArcGIS.ADF.ArcGISServer.RgbColor();
irgbc.Red = 50;
irgbc.Green = 255;
irgbc.Blue = 255;
irgbc.AlphaValue = 255;

ESRI.ArcGIS.ADF.ArcGISServer.FIDSet fids = new ESRI.ArcGIS.ADF.ArcGISServer.FIDSet();
int[] ids = new int[1];
ids[0] = Convert.ToInt32(key);
fids.FIDArray = ids;

ESRI.ArcGIS.ADF.ArcGISServer.MapDescription mapdesc = ((MapFunctionality)mf).MapDescription;
ESRI.ArcGIS.ADF.ArcGISServer.LayerDescription[] layerdescs = mapdesc.LayerDescriptions;
ESRI.ArcGIS.ADF.ArcGISServer.LayerDescription layerdesc = layerdescs[layerid];
layerdesc.Visible = true;
layerdesc.ShowSelectionBuffer = true;
layerdesc.SelectionFeatures = fids.FIDArray;

By using LayerDescription.ShowSelectBuffer, the feature is outlined with the highligh color, instead of filled in. This gives us the ability to see what is within the feature, while still knowing where the feature was located.

References:

http://forums.esri.com/Thread.asp?c=158&f=2276&t=211190&mc=12#msgid719661

http://forums.esri.com/Thread.asp?c=158&f=2276&t=223224&mc=1

ESRI breaks my custom zoom to method

I have an ArcGIS Server application. The client didn't like the standard format ESRI uses for displaying search results. So I made my own version. Basically, I return an HTML table through Callback scripting and populate a DIV with it. That table contains a column which is a hyperlink which calls functionality to zoom to that particular feature. Here's my code for that:

 System.Data.DataTable dataTable = null;
ESRI.ArcGIS.ADF.Web.DataSources.IMapFunctionality mf = (ESRI.ArcGIS.ADF.Web.DataSources.IMapFunctionality )Map1.GetFunctionality(0);
if (mf != null)
{
    ESRI.ArcGIS.ADF.Web.DataSources.IGISResource gisresource = mf.Resource;
    bool supported = gisresource.SupportsFunctionality(typeof(ESRI.ArcGIS.ADF.Web.DataSources.IQueryFunctionality));
    int shapeInd = -1;
    if (supported)
    {
        ESRI.ArcGIS.ADF.Web.DataSources.IQueryFunctionality qfunc;
        qfunc = (ESRI.ArcGIS.ADF.Web.DataSources.IQueryFunctionality)gisresource.CreateFunctionality(typeof(ESRI.ArcGIS.ADF.Web.DataSources.IQueryFunctionality), null);
        string[] lids;
        string[] lnames;
        qfunc.GetQueryableLayers(null, out lids, out lnames);

All this works splendidly...or at least it did. That was until I went an used ESRI's MapIdentify tool. This tool by default puts things in the task results panel. When I used the zoom to functionality in the task results panel, I noticed that my custom zoom to method suddenly quick functioning. This was distressing to say the least. It seems that every time I actually start to feel like I somewhat understand ArcGIS, I get blind-sided by something stupid like this.

After some careful debugging, I discovered what was happening was that ESRI stacks new MapResourceItems on top of the actual map when you interact with the task results. So originally my code was working fine when I was getting MapResourceItems[0] since that was the only MapResourceItem. But after running the task results, both the layer names and layer ids returned from the GetQueryalbleLayers() method were coming back as GUIDs.

My solution was to loop through all MapResourceItems until I found a MapResourceItem with a name that matches the map name.

  System.Data.DataTable dataTable = null;
 ESRI.ArcGIS.ADF.Web.DataSources.IMapFunctionality mf = null;
 for (int i = 0; i < this.MapResourceManager1.ResourceItems.Count; i++)
 {
    if (string.Compare(this.MapResourceManager1.ResourceItems[i].Name, this.m_mapName, true) == 0)
    {
  mf = (ESRI.ArcGIS.ADF.Web.DataSources.IMapFunctionality)Map1.GetFunctionality(i);
    }
 }
 if (mf != null)
 {
   ESRI.ArcGIS.ADF.Web.DataSources.IGISResource gisresource = mf.Resource;
   bool supported = gisresource.SupportsFunctionality(typeof(ESRI.ArcGIS.ADF.Web.DataSources.IQueryFunctionality));
   int shapeInd = -1;
   if (supported)
   {
      ESRI.ArcGIS.ADF.Web.DataSources.IQueryFunctionality qfunc;
      qfunc = (ESRI.ArcGIS.ADF.Web.DataSources.IQueryFunctionality)gisresource.CreateFunctionality(typeof(ESRI.ArcGIS.ADF.Web.DataSources.IQueryFunctionality), null);
      string[] lids;
      string[] lnames;
      qfunc.GetQueryableLayers(null, out lids, out lnames);