IPointSnapper.ClearCache Method

Clears the underlying snapping cache.

[Visual Basic .NET]
Public Sub ClearCache ( _
)

[C#]
public void ClearCache (
);

[C++]
HRESULT ClearCache(
void
);

Product Availability

Remarks

While Snapping is enabled and calls to IPointSnapper.Snap are being made, a cache of the visible features is being actively maintained. 

The cache is cleared in a number of instances for you; as a developer you do not need to account for these situations.  The following list describes the cases when ClearCache is called.

• A layer is added, moved, or deleted from the table of contents.
• The scale suppression of a layer is changed.
• The visibility of a layer is changed.
• A definition query on a layer is changed.
• A SQL query on a layer is changed.
• A layer’s data source is changed.
• A feature is created, updated, or deleted
• The extent of the map changes.
• The active data frame changes.
• The active view changes (e.g. focus changes from main map window to a viewer window or you switch from data view to layout view in ArcMap)
• The Snapping tolerance (ISnappingEnvironment.Tolerance) is updated.
• Intersection snapping is turned on or off.
• Text Snapping is enabled or disabled.
• CachedShapes, UpdateCachedShapes, or RemoveCachedShapes is called.
• ExcludeIMSLayers property is changed.

When any of the following events are fired, the snapping cache is cleared.

• IHookHelperEvents.OnHookUpdated
• IActiveViewEvents.ContentsChanged
• IActiveViewEvents.FocusMapChanged
• IObjectClassEvents.OnChange
• IObjectClassEvents.OnCreate
• IObjectClassEvents.OnDelete

There is no method to build the cache explicitly; this is handled internally when a client issues a call to IPointSnapper.Snap, at which time it is determined whether the cache needs to be rebuilt.

See Also