GetPreviousKey Method

Visual Basic
C#
WinRT C#
Objective-C
Java
WinRT JavaScript
C++

public DicomElement GetPreviousKey( 
   DicomElement element,
   bool tree
)

'Declaration
 
Public Function GetPreviousKey( _
   ByVal element As DicomElement, _
   ByVal tree As Boolean _
) As DicomElement

'Usage
 
Dim instance As DicomDataSet
Dim element As DicomElement
Dim tree As Boolean
Dim value As DicomElement
 
value = instance.GetPreviousKey(element, tree)

public DicomElement GetPreviousKey( 
   DicomElement element,
   bool tree
)

ObjectiveC Syntax

 function Leadtools.Dicom.DicomDataSet.GetPreviousKey( 
   element ,
   tree 
)

public:
DicomElement^ GetPreviousKey( 
   DicomElement^ element,
   bool tree
)

Parameters

element: An item in the Data Set. The item in the Data Set that immediately precedes this item will be returned.
tree: true to evaluate the Data Set as a tree; false to evaluate the Data Set as a list.

Return Value

The item in the Data Set that immediately precedes the item specified by element, or a null reference (Nothing in Visual Basic) if there is no item preceding element (element is the first item in the Data Set).

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

If the passed object points to:	The method returns an object pointing to:
Item 1	Item 2
Item 3	Item 4
Item 5	null
Item 6	Item 7

If the Data Set is evaluated as a list, the previous item in the list is returned. Please note that the numbering of the items in the following illustration does indicate the order of the items when the Data Set is evaluated as a list.

If the passed object points to:	The method returns an object pointing to:
Item 1	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:

GetFirstKey

GetNextKey

GetLastKey

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

GetRootKey

GetParentKey

GetChildKey

For an example, refer to Reset.

Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference

DicomDataSet Class
DicomDataSet Members
GetFirstKey Method
GetNextKey Method
GetRootKey Method
GetParentKey Method
GetChildKey Method