Description
This event is raised several different times in response to the user initiating a LoadCB method to load an image via Call Back.
Syntax
| Visual Basic |
|---|
Public Event CB( _ ByVal ID As Integer, _ ByVal CBID As enumIXEVENT_CB_ID _ ) |
Parameters
- ID
- Specifies which image buffer is being processed.
- CBID
An enumIXEVENT_CB_ID value which determines the type of call back.Value Description CBID_CLOSE The decompressor completed decompressing the data and is notifying the user to perform any clean-up such as file closing, etc. CBID_OPEN User should open data sources and do any memory allocation/initialization to this. CBID_READ The decompressor is requesting more data, which the user should supply through the WriteCBData and WriteCBDataPtr methods.
Remarks
For read events, return non-zero values as long as there is more data available. When all the data has been presented, return zero to signal the load process to finish.
Note: If the CBID_READ event is issued after a call to WriteCBData or WriteCBDataPtr with a data length of 0, then additional calls to WriteCBData or WriteCBDataPtr with a data length of 0 may be necessary.