DLL

To customize virtual mode

1. Call the SSVSetBufferSize function and set the parameters as follows:
   1. Set the dBufferSize parameter to specify the number of rows read into the virtual buffer at a time.
      If the sheet can display more rows at a time than the number of rows specified, the value of the dBufferSize parameter is reset to the number of rows the sheet can display.
   2. Set the dOverlap parameter to specify the total number of previously retrieved rows that are retained in a buffer.
2. Call the SSVSetStyle function and set the lStyle parameter as follows:
   • Set the value to SSV_SCROLLBARSHOWBUFFER to have the vertical scroll bar reflect only the number of rows in the virtual buffer rather than the total number of rows.
   • Set the value to SSV_NOROWNUMBERS to hide the text in the row header column.
   • Set the value to SSV_SCROLLBARSHOWBUFFER combined with SSV_NOROWNUMBERS using the Or operator.
3. If the scroll bar is reflecting the total number of rows or if the control displays the row headers with numbers, call the SSVSetMax function and set the Max parameter to the number of rows in the sheet.
4. Each time data is loaded into the buffer, in the SS_VQUERYDATA structure, set the RowsLoaded field to the number of rows that have been loaded.
   When the sheet requests data, it sends the SSM_VQUERYDATA message. The SS_VQUERYDATA structure provides information to this message about the data loaded into the buffer.