private static ValueList GetPixelData(IMap map, IEnvelope extent, HashSet <string> includeFields)
{
ValueList result = new ValueList();
for (int i = 0; i < map.LayerCount; i += 1)
{
ILayer layer = map.get_Layer(i);
if (!layer.Visible)
{
continue;
}
IIdentify id = layer as IIdentify;
if (id == null)
{
continue;
}
IArray data = id.Identify(extent);
if (data != null)
{
for (int j = 0; j < data.Count; j += 1)
{
object foundObj = data.get_Element(j);
IRasterIdentifyObj2 raster = foundObj as IRasterIdentifyObj2;
IRowIdentifyObject row = foundObj as IRowIdentifyObject;
if (raster != null)
{
int propertyIndex = 0;
string property;
string value;
while (true)
{
try {
raster.GetPropAndValues(propertyIndex, out property, out value);
if ((!"NoData".Equals(value)) &&
((includeFields == null) || includeFields.Contains(property)))
{
result.Add(property, value);
}
propertyIndex += 1;
} catch {
break;
}
}
continue;
}
else if (row != null)
{
IFields fields = row.Row.Fields;
for (int k = 0; k < fields.FieldCount; k += 1)
{
string fieldName = fields.get_Field(k).Name;
if ((includeFields == null) ? (!result.ContainsKey(fieldName)) : includeFields.Contains(fieldName))
{
result.Add(fieldName, row.Row.get_Value(k));
}
}
}
}
break;
}
}
return(result);
}
private static Dictionary <string, object> CollectData(IMap map, IEnvelope extent, HashSet <string> includeFields)
{
const int tileSize = 128;
double cellWidth = extent.Width / (tileSize - 1);
double cellHeight = extent.Height / (tileSize - 1);
Dictionary <ValueList, List <Cell> > dataCells = new Dictionary <ValueList, List <Cell> >();
for (int y = 0; y < tileSize; y += 1)
{
for (int x = 0; x < tileSize; x += 1)
{
EnvelopeClass pixelExtent = new EnvelopeClass();
pixelExtent.XMin = extent.XMin + x * cellWidth;
pixelExtent.XMax = pixelExtent.XMin + cellWidth;
pixelExtent.YMax = extent.YMax - y * cellHeight;
pixelExtent.YMin = pixelExtent.YMax - cellHeight;
ValueList cellData = GetPixelData(map, pixelExtent, includeFields);
if (cellData.Count > 0)
{
if (dataCells.ContainsKey(cellData))
{
dataCells[cellData].Add(new Cell(y, x));
}
else
{
List <Cell> cells = new List <Cell>();
cells.Add(new Cell(y, x));
dataCells[cellData] = cells;
}
}
}
}
StringBuilder[] grid = new StringBuilder[tileSize];
for (int i = 0; i < tileSize; i += 1)
{
grid[i] = new StringBuilder(new String(' ', tileSize));
}
List <string> keys = new List <string>();
keys.Add("");
Dictionary <string, object> data = new Dictionary <string, object>();
int keyIndex = 0;
foreach (KeyValuePair <ValueList, List <Cell> > d in dataCells)
{
if (d.Key.Count > 0)
{
char code = EncodeChar(keys.Count);
string key = keyIndex.ToString();
foreach (Cell cell in d.Value)
{
grid[cell.Row][cell.Col] = code;
}
keys.Add(key);
data.Add(key, d.Key);
keyIndex += 1;
}
}
if (keys.Count > 1)
{
Dictionary <string, object> result = new Dictionary <string, object>();
result.Add("grid", grid.Select(sb => sb.ToString()).ToArray());
result.Add("keys", keys.ToArray());
result.Add("data", data);
return(result);
}
else
{
return(null);
}
}
