public static int CalculateSpeceficValuesCount(string requireColumnName, string fieldValue, ShapeFileFeatureLayer featureLayer)
{
int count = 0;
if (!String.IsNullOrEmpty(requireColumnName))
{
featureLayer.SafeProcess(() =>
{
string dbfPath = Path.ChangeExtension(featureLayer.ShapePathFilename, ".dbf");
if (File.Exists(dbfPath))
{
using (GeoDbf dbf = new GeoDbf(dbfPath))
{
dbf.Open();
string orignalColumnName = requireColumnName;
for (int i = 1; i <= dbf.RecordCount; i++)
{
var currentFieldValue = dbf.ReadFieldAsString(i, orignalColumnName);
if (currentFieldValue.Equals(fieldValue, StringComparison.Ordinal))
{
count++;
}
}
dbf.Close();
}
}
});
}
return(count);
}
public static IEnumerable <IGrouping <string, string> > GroupColumnValues(string requireColumnName
, ShapeFileFeatureLayer featureLayer)
{
Collection <string> fieldValues = new Collection <string>();
if (!String.IsNullOrEmpty(requireColumnName))
{
featureLayer.SafeProcess(() =>
{
string dbfPath = Path.ChangeExtension(featureLayer.ShapePathFilename, ".dbf");
if (File.Exists(dbfPath))
{
string orignalColumnName = requireColumnName;
using (GeoDbf dbf = new GeoDbf(dbfPath))
{
dbf.Open();
for (int i = 1; i <= dbf.RecordCount; i++)
{
fieldValues.Add(dbf.ReadFieldAsString(i, orignalColumnName));
}
dbf.Close();
}
}
});
}
return(fieldValues.GroupBy(fieldValue => fieldValue));
}
/// <summary>
/// Points to Draw Elapsed MS
/// 10000 605
/// 20000 998
/// 50000 2658
/// 100000 4980
/// </summary>
private static double GetRecommendPointToValueRatio(FeatureLayer layer, string columnName)
{
int pointsToDraw = 0;
// better performance.
if (layer is ShapeFileFeatureLayer)
{
var shpLayer = (ShapeFileFeatureLayer)layer;
var shpFName = shpLayer.ShapePathFilename;
var dbfFName = Path.ChangeExtension(shpFName, ".dbf");
if (File.Exists(dbfFName))
{
using (GeoDbf geoDbf = new GeoDbf(dbfFName, GeoFileReadWriteMode.Read))
{
geoDbf.Open();
for (int i = 1; i <= geoDbf.RecordCount; i++)
{
string fieldValue = geoDbf.ReadFieldAsString(i, columnName);
try
{
pointsToDraw += (int)Convert.ToDouble(fieldValue);
}
catch (Exception ex)
{
GisEditor.LoggerManager.Log(LoggerLevel.Debug, ex.Message, new ExceptionInfo(ex));
}
}
geoDbf.Close();
}
}
}
else
{
IEnumerable <Feature> features = null;
layer.SafeProcess(() => { features = layer.QueryTools.GetAllFeatures(new string[] { columnName }); });
pointsToDraw = features.Sum(tmpFeature =>
{
try { return((int)Convert.ToDouble(tmpFeature.ColumnValues[columnName])); }
catch (Exception ex)
{
GisEditor.LoggerManager.Log(LoggerLevel.Debug, ex.Message, new ExceptionInfo(ex));
return(0);
}
});
}
double pointToValueRatio = 1d;
if (maxDotsToDraw < pointsToDraw)
{
pointToValueRatio = (double)maxDotsToDraw / (double)pointsToDraw;
}
return(pointToValueRatio);
}