ImageGear for C and C++ on Windows v19.10 - Updated
MED_ElemList_move_prev
API Reference Guide > MD Component API Reference > MD Component Functions Reference > Data Set Element List Functions > MED_ElemList_move_prev

This function moves the Current Data Element to the previous Data Element in the Element List.

Declaration:

 
Copy Code
AT_ERRCOUNT ACCUAPI MED_ElemList_move_prev(
        HIGMEDELEMLIST hIGMedElemList, 
        AT_MODE level_op,
        LPLONG lpNumRemaining
);

Arguments:

Name Type Description
hIGMedElemList HIGMEDELEMLIST HIGMEDELEMLIST handle to the Data Element List object.
level_op AT_MODE

A variable of type AT_MODE that tells the function how to move when it comes to an SQ. SQs are like indented outline items, allowing for hierarchies of Data Elements. Set this to one of the following constants:

  • MED_DCM_MOVE_LEVEL_FIXED: This setting tells the function to move only within the same level as the previous Current DE. An SQ and all its Data Elements are skipped over. If you are in a SQ, you can only move about the SQ.
  • MED_DCM_MOVE_LEVEL_FLOAT: This setting tells the function to move up or down as needed to get to the next DE. If the next DE is an SQ the Current DE moves down into it. At the end of the SQ, the Current DE moves back out to the lower levels (for example, from Level 2 to Level 1).
lpNumRemaining LPLONG A far pointer to a LONG that returns the number of DE remaining until the top is reached. If the returned value is 0, you are now at first DE, if the returned value is -1, you have attempted to move past the first DE.

Return Value:

Returns the number of ImageGear errors that occurred during the function call.

Supported Raster Image Formats:

This function does not process image pixels.

Remarks:

The value of lpNumRemaining tells you whether the Tag has now become the first Tag in the list.

The level_op setting determines whether the Current Data Element can move from level to level, or has to stay on the same level.