IScreenDisplay.AddCache Method

Creates a new cache and return its ID. The ID can be specified to StartDrawing to direct output to the cache. It can also be used with a number of other methods such as DrawCache and Invalidate.

[Visual Basic .NET]
Public Function AddCache ( _
) As Short

[C#]
public short AddCache (
);

[C++]
HRESULT AddCache(
  short* cacheID
);

[C++]

Parameters
cacheID [out, retval]
  cacheID is a parameter of type short

Product Availability

Remarks

ScreenDisplay objects make it possible for clients to create any number of caches.  A cache is an off screen bitmap representing the application's window.  Instead of drawing directly to the screen, graphics are drawn into caches, then the caches are drawn on the screen.  When the application's window is obscured and requires redrawing, it done so from the caches instead of from a database.  In this way, caches improve drawing performance - bitmap rendering is faster than reading and displaying data from a database.

In general, a Map object creates three caches: one for all the layers, another if there are annotation or graphics, and a third cache if there is a feature selection.  A layer can create its own private cache if it sets ILayer::Cached equal to TRUE.  In this case, the Map will create a separate cache for the layer and groups the layers above and below it into different caches.

The AppDisplay object has no implementation for this method.

See Also

.NET Related Topics