/// <summary>
/// Uses the settings on this scheme to create a random category.
/// </summary>
/// <returns>A new IFeatureCategory</returns>
public override IFeatureCategory CreateRandomCategory(string filterExpression)
{
LineCategory result = new LineCategory();
Color fillColor = CreateRandomColor();
result.Symbolizer = new LineSymbolizer(fillColor, 2);
result.FilterExpression = filterExpression;
result.LegendText = filterExpression;
return result;
}
/// <summary>
/// creates a new instance of the PointScheme, but assigns the specified symbolizer
/// as the symbolizer to use on a single default category.
/// </summary>
/// <param name="extent">The geographic point size for the default will be 1/100th the specified extent</param>
public LineScheme(IEnvelope extent)
{
Configure();
LineCategory def = new LineCategory(extent);
Categories.Add(def);
}
/// <summary>
/// Calculates the unique colors as a scheme
/// </summary>
/// <param name="fs">The featureset with the data Table definition</param>
/// <param name="uniqueField">The unique field</param>
public Hashtable GenerateUniqueColors(IFeatureSet fs, string uniqueField)
{
Hashtable result = new Hashtable(); // a hashtable of colors
DataTable dt = fs.DataTable;
ArrayList vals = new ArrayList();
int i = 0;
foreach (DataRow row in dt.Rows)
{
if (uniqueField != "FID")
{
if (vals.Contains(row[uniqueField]) == false)
{
vals.Add(row[uniqueField]);
}
}
else
{
vals.Add(i);
i++;
}
}
Random rnd = new Random();
foreach (object item in vals)
{
Color c = rnd.NextColor();
while (result.ContainsKey(c))
{
c = rnd.NextColor();
}
LineCategory cat = new LineCategory(c, 1);
string flt = "[" + uniqueField + "] = ";
if(uniqueField == "FID")
{
flt += item;
}
else
{
if (dt.Columns[uniqueField].DataType == typeof(string))
{
flt += "'" + item + "'";
}
else
{
flt += item.ToString();
}
}
cat.FilterExpression = flt;
Categories.Add(cat);
result.Add(c, item);
}
return result;
}