ImageGear for C and C++ on Windows v19.0
LPFNIG_MPCB_UPDATE
| API Reference Guide > Core Component API Reference > Core Component Callback Functions Reference > LPFNIG_MPCB_UPDATE |
Multi-page images allow you to notify the application about status changes. Use IG_mpi_CB_set to call code that associates the given multi-page image hMIGear with any lpPrivate data, and updates the defined function.
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typedef VOID (LPACCUAPI LPFNIG_MPCB_UPDATE)( DWORD dwCBID, LPVOID lpPrivate, AT_MODE nMode, UINT nPage, UINT nCount ); |
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| Name | Type | Description |
|---|---|---|
| dwCBID | DWORD | The identifier allocated for this callback function by IG_mpi_CB_set() |
| lpPrivate | LPVOID | The private data associated with this identifier |
| nMode | AT_MODE | The type of multi-page image change. |
| nPage | UINT | Usually the first number of the changed pages. |
| nCount | UINT | Usually the total number of changed pages. |
The following table lists all possible values for nMode and the appropriate sense of the nPage and nCount parameters:
| nMode | nPage | nCount | Description |
|---|---|---|---|
| IG_MPCBMODE_MPI_ DELETE | Not used | Not used | Notifies the application that the multi-page image is going to be deleted. |
| IG_MPCBMODE_MPI_ ASSOCIATED | Not used | Not used | Notifies the application that the multi-page image is associated with an external file. |
| IG_MPCBMODE_MPI_ CLOSE | No used | Not used | Notifies the application that the multi-page image is going to close the associated external file. |
| IG_MPCBMODE_MPI_ CB_SET | Not used | Not used | Notifies the application that this callback data is set. This notification receives only the callback function that has just been set. |
| IG_MPCBMODE_MPI_ CB_RESET | Not used | Not used | Notifies the application that this callback data is to be reset. |
| IG_MPCBMODE_MPI_ PAGEINSERTED | Index of where new pages start | Number of new pages inserted | Notifies the application that new pages have been inserted into the multi-page image. |
| IG_MPCBMODE_MPI_ PAGEUPDATED | Index of the first updated page | Number of updated pages starting from nPage | Indicates that the application has updated pages in the multi-page image. |
| IG_MPCBMODE_MPI_ PAGEDELETED | Index of first deleted page | Number of deleted pages | Indicates that the application has deleted pages in the multi-page image. |
| IG_MPCBMODE_MPF_ PAGEINSERTED | Index of where new pages start | Number of new pages inserted | Indicates that the application has inserted new pages into the external file image. |
| IG_MPCBMODE_MPF_ PAGEUPDATED | Index of the first updated page | Number of updated pages starting from nPage | Indicates that the application has updated pages in the external multi-page image file. |
| IG_MPCBMODE_MPF_ PAGEDELETED | Index of the first deleted page | Number of deleted pages | Application deleted pages in the external multi-page image file. |
None
This function does not process image pixels.
This callback function returns a unique identifier, which allows multi-page associations with the given information. After the association is made, the application receives notifications about changes to the multi-page image through this function.
The notification function blocks the execution of the operation that performed the action. This function can be used for thread synchronization. We do not recommended that you call a multi-page API from the notification function (to prevent an unlimited loop from occurring).