如何轉換的DataSet爲FeatureDataset

Question

我試圖從數據集中的幾何數據得到一個爲FeatureDataset：

private void QueryCustomer(DataSet ds) 
     { 

      SharpMap.Data.FeatureDataSet ds_feature = new SharpMap.Data.FeatureDataSet(); 

      ds_feature = (SharpMap.Data.FeatureDataSet)ds; // ERROR HERE 
.. 

我越來越：

無法投類型的對象System.Data .DataSet'鍵入'SharpMap.Data.FeatureDataSet'

任何幫助，將不勝感激。謝謝。

Answer 1

無需創建DataSet。只需使用FeatureDataSet直接從SqLite獲取表格即可：

double x, y; 
FeatureDataSet fds = new FeatureDataSet(); 
Envelope env = new Envelope(double.MinValue, double.MaxValue, double.MinValue, double.MaxValue); 

SharpMap.Data.Providers.ManagedSpatiaLite p = new ManagedSpatiaLite(ConnectionString, Table, GeometryColumn.ToUpper(), KeyColumn.ToUpper()); 
p.Open(); 
p.ExecuteIntersectionQuery(env, fds); 
foreach (FeatureDataRow fdr in ((FeatureDataTable)fds.Tables[0]).Rows) 
{ 
x = fdr.Geometry.Centroid.X; 
y = fdr.Geometry.Centroid.Y; 
//...process x and y here... 
} 
p.Close(); 
p.Dispose();