ReadOperator.Query Property
Gets or sets the additional query parameters the operator uses when it reads from the DataSet.
Syntax
public Query Query { get; set; }Property Value
Default: null
Additional query parameters the operator uses when it reads from the dataset.
Remarks
A Query gives an application the possibility to specify dataset-dependent parameters that are used by a ReadOperator when it reads features from a data set. This is often used to limit which features and/or attributes that are read but can also contain parameters that optimize the read operation.
If the query property is a null reference, it is the same as using a Query with all default values, which usually means that all features and attributes are read by the ReadOperator.
Some data sets have specific query types that provide additional query parameters. For example, the VpfQuery which provides additional parameters that can be used when reading from a VpfDataSet.
Example
// Set a query at the ReadOperator, which filters out rasters
public static void SetNoRastersQuery(ReadOperator readOperator)
{
// This property is a member of a type that might be referred to by a View
// or a GlobeView, either directly or indirectly through other objects, which means
// that you must use the Guard class to take the global configuration lock when it
// is modified to synchronize access with any running Carmenta Engine threads.
using (Guard guard = new Guard())
{
// Create a query to filter out rasters
Query noRastersQuery = new Query();
noRastersQuery.ReadRasters = false;
// Set the no raster query in the ReadOperator
readOperator.Query = noRastersQuery;
}
}
Platforms
Windows, Linux, Android