MovePrevElement method

Builder Syntax	int __fastcall MovePrevElement(bool bTree);
Delphi Syntax	function MovePrevElement(bTree: Boolean): Integer;
Overview	Refer to Working with Data Sets.

Remarks

Updates the CurrentElement property with the item in the Data Set that immediately precedes the item specified in the CurrentElement property. The result depends on whether the Data Set is evaluated as a tree or a list.

If the Data Set is evaluated as a tree structure, this method updates the CurrentElement property with the previous item on the same level and with the same parent as the item specified in the CurrentElement property. Please note that the numbering of the items in this illustration is arbitrary and does not imply order.

$image\GetPvTr.gif$

If the CurrentElement property contains:	The CurrentElement property will be updated with:
Item 1	Item 2
Item 3	Item 4
Item 5	Nil (NULL)
Item 6	Item 7

If the Data Set is evaluated as a list, the CurrentElement property is updated with the previous item in the list. Please note that the numbering of the items in this illustration does indicate the order of the items when the Data Set is evaluated as a list.

$image\GetPvLst.gif$

If the CurrentElement property contains:	The CurrentElement property will be updated with:
Item 1	Nil (NULL)
Item 15	Item 14
Item 5	Item 4
Item 9	Item 8
Item 22	Item 21
Item 25	Item 24

The following methods will also help you navigate the Data Set as either a tree or a list:

MoveFirstElement method

MoveLastElement method

MoveNextElement method

If you evaluate the IOD Structure as a tree, you can also use the following methods to navigate the tree:

MoveRootElement method

MoveParentElement method

MoveChildElement method

Note: You can either check the return value of the method, or capture and process errors to determine whether the MovexxxElement methods have completed successfully. For an example of capturing errors, refer to any of the MovexxxElement method examples.