Implementation of ArcGIS Server Thematic Map

Recently, I have studied the implementation of the ArcGIS Server Web ADF (9.2) Thematic Map as follows (taking the bar chart as an example, the pie chart is similar to the histogram). I hope it will help you! // Obtain the layer ID of the topic.
..........
Int layerid = 3;

// Obtain the attribute name list of the topic graph analysis element.
String [] fieldname = new string [2];
Fieldname [0] = "pop1990 ";
Fieldname [1] = "pop1999 ";


// Obtain the layer object (featurelayer) of the topic graph analysis)
Agslocalmapresource res = (agslocalmapresource) This. webcontext
. Getresources (). Get ("ags0 ");
Mapserver = res. getlocalmapserver ();
Ilayer filayer = mapserver. getlayer (mapserver. getmapname (0), layerid );
Featurelayer flayer = (featurelayer) filayer;


// Create a chartrenderer object. Note: Use the createarcobject (string) method of the agslocalmapresource object to create an AO object in the Web ADF.
Chartrenderer chartrender = (chartrenderer) res
. Createarcobject (chartrenderer. getclsid ());

// Specify the Field Values in each column of the bar chart in irendererfileds.
Irendererfields rendererfields = chartrender;
Rendererfields. addfield (fieldname [0], null );
Rendererfields. setfieldalias (0, rendererfields. getfield (0 ));
Rendererfields. addfieldfieldname [1], null );
Rendererfields. setfieldalias (1, rendererfields. getfield (1 ));

// Find the maximum value required for each element's specified attribute
Queryfilter = (queryfilter) res
. Createarcobject (queryfilter. getclsid ());
Queryfilter. addfield (fieldname [0]);
Queryfilter. addfield (fieldname [1]);
Icursor cursor = flayer. itable_search (queryfilter, true );
Int numfields = 2; // Number of bar chart Columns
Int [] fieldindecies = new int [numfields];
Fieldindecies [0] = flayer. findfield (fieldname [0]);
Fieldindecies [1] = flayer. findfield (fieldname [1]);
Double maxvalue = 0;
Boolean firstvalue = true;
Irowbuffer ROW = cursor. nextrow ();
While (row! = NULL ){
String fieldvalue = "";
For (INT fieldindex = 0; fieldindex <numfields; fieldindex ++ ){
Double fieldvalue = double. parsedouble (row. getvalue (
Fieldindecies [fieldindex]). tostring ());
If (firstvalue ){
Maxvalue = fieldvalue;
Firstvalue = false;
}
If (fieldvalue> maxvalue)
Maxvalue = fieldvalue;
}
Row = cursor. nextrow ();
}


// Instantiate a chart object
Barchartsymbol = (barchartsymbol) res. createarcobject (barchartsymbol. getclsid ());

Ichartsymbol chartsymbol = barchartsymbol;
Barchartsymbol. setwidth (10 );
Imarkersymbol markersymbol = barchartsymbol;
Chartsymbol. setmaxvalue (maxvalue );
Markersymbol. setsize (60 );


// Set the fill color and line color of each column in the bar chart

Isymbolarray symbolarray = barchartsymbol;
Simplefillsymbol fillsymbol1 = (simplefillsymbol) res. createarcobject (simplefillsymbol. getclsid ());
Irgbcolor rgbcolor1 = (rgbcolor) res. createarcobject (rgbcolor. getclsid ());

Rgbcolor1.setred (255 );
Rgbcolor1.setgreen (0 );
Rgbcolor1.setblue (0 );
Rgbcolor1.setusewindowsdithering (true );

Ilinesymbol ilinesym1 = (ilinesymbol) res. createarcobject (simplelinesymbol. getclsid ());
Ilinesym1.setcolor (rgbcolor1 );
Ilinesym1.setwidth (1 );
Fillsymbol1.setoutline (ilinesym1 );

Fillsymbol1.setcolor (rgbcolor1 );
Barchartsymbol. addsymbol (fillsymbol1 );

Simplefillsymbol fillsymbol2 = (simplefillsymbol) res. createarcobject (simplefillsymbol. getclsid ());

Irgbcolor rgbcolor2 = (rgbcolor) res. createarcobject (rgbcolor. getclsid ());

Rgbcolor2.setred (238 );
Rgbcolor2.setgreen (1, 195 );
Rgbcolor2.setblue (235 );
Rgbcolor2.setusewindowsdithering (true );

Ilinesymbol ilinesym2 = (ilinesymbol) res. createarcobject (simplelinesymbol. getclsid ());
Ilinesym2.setcolor (rgbcolor2 );
Ilinesym2.setwidth (1 );
Fillsymbol2.setoutline (ilinesym2 );
Fillsymbol2.setcolor (rgbcolor2 );
Barchartsymbol. addsymbol (fillsymbol2 );

Chartrender. setchartsymbolbyref (chartsymbol );
Chartrender. setuseoverposter (false );
// Set the featurerenderer chartrenderer object
Flayer. setrendererbyref (chartrender );

// Refresh the Map Display chart
Map1.refresh ();
This. webcontext. Refresh ();