ICustomDataSet.Query Method
Gets all features matching the query parameters.
Thread safety: Implementations of this method might need to be thread-safe. Show
Query(Rectangle area, Query query, UInt64Collection ids, ViewInfo info)
Gets all features matching the query parameters.Syntax
public IQueryResult Query (
Rectangle area,
Query query,
UInt64Collection ids,
ViewInfo info
)Parameters
area
query
Type: Query
Specifies some additional filter parameters. Only features matching this query should be returned. If null, it should not limit the query.
Specifies some additional filter parameters. Only features matching this query should be returned. If null, it should not limit the query.
ids
Type: A collection of System.UInt64 (not available in C#) elements.
Only features with an identifier present in this list should be returned. If list is empty, all features should be returned.
Only features with an identifier present in this list should be returned. If list is empty, all features should be returned.
info
Type: ViewInfo
Additional information about the view and drawable.
Additional information about the view and drawable.
Return Value
Type: IQueryResult
A result object that iterates over all returned features.
A result object that iterates over all returned features.
Remarks
This is the main method of the dataset. It should return a IQueryResult instance, iterating over all features inside the update area which also match query and ids. You can create your own custom class implementing IQueryResult, or you can use the built-in CustomDataSetResult class. If the result is empty you can return null instead of instantiating an empty query result.
The update area is specified in the coordinate reference system of the custom dataset (as returned by the Crs property).
Platforms
Windows, Linux, Android