Hi all,
I want to create a dialog showing a one to many relationship of 2 dbf by an xBrowse Tree.
dbf 1 is "ID", "TASK"
|
+------+
|
dbf 2 is "ID", "TASK_ID", "date", "FROM", "TO"My problem is that at program start both dbf are empty.
Pressing a button 'ADD' allows the user to create entries.
How can i declare the xbrowse tree at beginning?
Regards, Detlef
Dear Detlef,
work in progress:
#include "FiveWin.ch"
request DbfCdx
function Main()
local oDlg, oBrw
if ! File( "tasks.dbf")
DbCreate( "tasks.dbf", { ;
{ "ID", "+", 10, 0 }, ;
{ "TASK", "C", 50, 0 } } )
endif
if ! File( "details.dbf")
DbCreate( "details.dbf", { ;
{ "ID", "N", 10, 0 }, ;
{ "TASK_ID", "N", 10, 0 },;
{ "DATE", "D", 8, 0 },;
{ "FROM", "C", 50, 0 },;
{ "TO", "C", 50, 0 } } )
endif
USE tasks VIA "DBFCDX"
if Tasks->( RecCount() ) == 0
Tasks->( DbAppend() )
Tasks->Task := "Project Alpha"
endif
INDEX ON field->ID TO "ID"
SET ORDER TO TAG ID
USE details VIA "DBFCDX" NEW
if Details->( RecCount() ) == 0
Details->( DbAppend() )
Details->Task_id := Tasks->Id
Details->Date := Date()
endif
INDEX ON field->Task_id TO "TASK_ID"
SET ORDER TO TAG TASK_ID
SELECT "tasks"
SET RELATION TO details->Task_id INTO details
DEFINE DIALOG oDlg SIZE 1200, 400 PIXEL TRUEPIXEL
@ 2.5, 2 XBROWSE oBrw SIZE 1170, 350 OF oDlg ;
DATASOURCE "Tasks" ;
CELL LINES NOBORDER
oBrw:CreateFromCode()
oBrw:SetTree( BuildTree() )
oDlg:oClient = oBrw
ACTIVATE DIALOG oDlg CENTERED ;
ON INIT BuildBar( oDlg, oBrw )
return nil
function BuildBar( oDlg, oBrw )
local oBar
DEFINE BUTTONBAR oBar OF oDlg SIZE 50, 50 2007
DEFINE BUTTON OF oBar PROMPT "Task" ;
ACTION ( Tasks->( DbAppend() ), Details->( DbAppend() ),;
Details->Task_id := Tasks->Id, Details->Date := Date(), ;
oBrw:SetTree( BuildTree() ), oBrw:Refresh() )
DEFINE BUTTON OF oBar PROMPT "Detail" ;
ACTION ( details->( DbAppend() ), details->task_id := tasks->id, oBrw:SetTree( BuildTree() ), oBrw:Refresh() )
oDlg:Resize()
return .T.
function BuildTree()
local oTree, nRecNo := Tasks->( RecNo() )
if Tasks->( RecCount() ) > 0
TREE oTree
Tasks->( DbGoTop() )
while ! Tasks->( Eof() )
// Create parent item from tasks
TREEITEM tasks->Task
if Details->( RecCount( ) ) > 0
TREE
while details->Task_id == tasks->id .and. ! details->( Eof() )
TREEITEM DToC( details->Date ) + " " + details->From + " to " + details->To
details->(DbSkip())
end
ENDTREE
endif
tasks->(DbSkip())
end
ENDTREE
Tasks->( DbGoTo( nRecNo ) )
else
TREE oTree
ENDTREE
endif
return oTreeMany thanks Antonio.
This is a very helpful code for me to start with. :D
Kind regards
Enhanced version:
#include "FiveWin.ch"
request DbfCdx
function Main()
local oDlg, oBrw
if ! File( "tasks.dbf")
DbCreate( "tasks.dbf", { ;
{ "ID", "+", 10, 0 }, ;
{ "TASK", "C", 50, 0 } } )
endif
if ! File( "details.dbf")
DbCreate( "details.dbf", { ;
{ "ID", "N", 10, 0 }, ;
{ "TASK_ID", "N", 10, 0 },;
{ "DATE", "D", 8, 0 },;
{ "FROM", "C", 50, 0 },;
{ "TO", "C", 50, 0 } } )
endif
USE tasks VIA "DBFCDX"
if Tasks->( RecCount() ) == 0
Tasks->( DbAppend() )
Tasks->Task := "Project Alpha"
endif
INDEX ON field->ID TO "ID"
SET ORDER TO TAG ID
USE details VIA "DBFCDX" NEW
if Details->( RecCount() ) == 0
Details->( DbAppend() )
Details->Task_id := Tasks->Id
Details->Date := Date()
Details->From := "09:00"
Details->To := "11:00"
endif
INDEX ON field->Task_id TO "TASK_ID"
SET ORDER TO TAG TASK_ID
SELECT "tasks"
SET RELATION TO details->Task_id INTO details
DEFINE DIALOG oDlg SIZE 1200, 400 PIXEL TRUEPIXEL
@ 2.5, 2 XBROWSE oBrw SIZE 1170, 350 OF oDlg ;
DATASOURCE "Tasks" ;
CELL LINES NOBORDER
oBrw:CreateFromCode()
oBrw:SetTree( BuildTree() )
oBrw:aCols[ 1 ]:nWidth := 500
oBrw:bEdit = { | o | EditItem( o:oBrw:oTreeItem, o:oBrw ) }
oDlg:oClient = oBrw
ACTIVATE DIALOG oDlg CENTERED ;
ON INIT BuildBar( oDlg, oBrw )
return nil
function BuildBar( oDlg, oBrw )
local oBar
DEFINE BUTTONBAR oBar OF oDlg SIZE 50, 50 2007
DEFINE BUTTON OF oBar PROMPT "Task" ;
ACTION ( Tasks->( DbAppend() ), Details->( DbAppend() ),;
Details->Task_id := Tasks->Id, Details->Date := Date(),;
Details->From := "09:00", Details->To := "11:00",;
oBrw:oTree := BuildTree(), oBrw:Refresh() )
DEFINE BUTTON OF oBar PROMPT "Detail" ;
ACTION ( Details->( DbAppend() ), Details->task_id := Tasks->id,;
Details->Date := Date(), Details->From := "09:00",;
Details->To := "11:00",;
oBrw:oTree := BuildTree(), oBrw:Refresh() )
DEFINE BUTTON OF oBar PROMPT "Edit" ACTION oBrw:Edit()
DEFINE BUTTON OF oBar PROMPT "Del"
oDlg:Resize()
return .T.
function BuildTree()
local oTree, nRecNo := Tasks->( RecNo() )
if Tasks->( RecCount() ) > 0
TREE oTree
Details->( DbGoTop() )
Tasks->( DbGoTop() )
while ! Tasks->( Eof() )
TREEITEM tasks->Task CARGO { "task", Tasks->( RecNo() ) }
if Details->( RecCount() ) > 0
TREE
while Details->Task_id == tasks->id .and. ! Details->( Eof() )
TREEITEM "Date: " + DToC( Details->Date ) + ;
" - From: " + RTRim( Details->From ) + ;
" - To: " + RTrim( Details->To ) ;
CARGO { "detail", Details->( RecNo() ) }
Details->( DbSkip() )
end
ENDTREE
endif
Tasks->( DbSkip() )
end
ENDTREE
Tasks->( DbGoTo( nRecNo ) )
else
TREE oTree
ENDTREE
endif
return oTree
function EditItem( oTreeItem, oBrw )
local nRec := oTreeItem:Cargo[ 2 ], oDlg
local nBrwPos := oBrw:nRowSel
if oTreeItem:Cargo[ 1 ] == "detail"
DEFINE DIALOG oDlg SIZE 400, 220 PIXEL TRUEPIXEL TITLE "Edit detail"
Details->( DbGoTo( nRec ) )
@ 1, 2 SAY "Date:" OF oDlg
@ 1, 6 GET Details->Date PICTURE "9999-99-99" OF oDlg
@ 3.2, 2 SAY "From:" OF oDlg
@ 3.5, 6 GET Details->From PICTURE "99:99" OF oDlg
@ 5.3, 2 SAY "To:" OF oDlg
@ 5.9, 6 GET Details->To PICTURE "99:99" OF oDlg
@ 10, 14 BUTTON "OK" OF oDlg SIZE 80, 25 ;
ACTION ( Details->( DbCommit() ), oDlg:End(),;
oBrw:oTree := BuildTree(), oBrw:nRowSel := nBrwPos, oBrw:Refresh() )
@ 10, 34 BUTTON "Cancel" OF oDlg SIZE 80, 25 ACTION oDlg:End()
ACTIVATE DIALOG oDlg CENTERED
else
DEFINE DIALOG oDlg SIZE 400, 220 PIXEL TRUEPIXEL TITLE "Edit task"
Tasks->( DbGoTo( nRec ) )
@ 1, 2 SAY "Task:" OF oDlg
@ 1, 6 GET Tasks->Task SIZE 340, 20 OF oDlg
@ 10, 14 BUTTON "OK" OF oDlg SIZE 80, 25 ;
ACTION ( Tasks->( DbCommit() ), oDlg:End(),;
oBrw:oTree := BuildTree(), oBrw:Refresh() )
@ 10, 34 BUTTON "Cancel" OF oDlg SIZE 80, 25 ACTION oDlg:End()
ACTIVATE DIALOG oDlg CENTERED
endif
return nilThanks again, Antonio. That gets me much further.
Mr.Detlef,
Please remove the following line
:DATASOURCE "Tasks" ;
under @ 2.5, 2 XBROWSE oBrw SIZE 1170, 350 OF oDlg ; Clause
to avoid runtime error, when testing the sample code.
-Ramesh Babu P
Enhanced version:
detlef.prg
#include "FiveWin.ch"
request DbfCdx
function Main()
local oDlg, oBrw
if ! File( "tasks.dbf")
DbCreate( "tasks.dbf", { ;
{ "ID", "+", 10, 0 }, ;
{ "TASK", "C", 50, 0 } } )
endif
if ! File( "details.dbf")
DbCreate( "details.dbf", { ;
{ "ID", "N", 10, 0 }, ;
{ "TASK_ID", "N", 10, 0 },;
{ "DATE", "D", 8, 0 },;
{ "FROM", "C", 50, 0 },;
{ "TO", "C", 50, 0 } } )
endif
USE tasks VIA "DBFCDX"
if Tasks->( RecCount() ) == 0
Tasks->( DbAppend() )
Tasks->Task := "Project Alpha"
endif
INDEX ON field->ID TO "ID"
SET ORDER TO TAG ID
USE details VIA "DBFCDX" NEW
if Details->( RecCount() ) == 0
Details->( DbAppend() )
Details->Task_id := Tasks->Id
Details->Date := Date()
Details->From := "09:00"
Details->To := "11:00"
endif
INDEX ON field->Task_id TO "TASK_ID"
SET ORDER TO TAG TASK_ID
SELECT "tasks"
SET RELATION TO details->Task_id INTO details
DEFINE DIALOG oDlg SIZE 1200, 400 PIXEL TRUEPIXEL
@ 2.5, 2 XBROWSE oBrw SIZE 1170, 350 OF oDlg ;
DATASOURCE "Tasks" ;
CELL LINES NOBORDER
oBrw:CreateFromCode()
oBrw:SetTree( BuildTree() )
oBrw:aCols[ 1 ]:nWidth := 500
oBrw:bEdit = { | o | EditItem( o:oBrw:oTreeItem, o:oBrw ) }
oBrw:bChange = { | o | If( Len( o:oTreeItem:Cargo ) == 2,;
Tasks->( DbGoTo( o:oTreeItem:Cargo[ 2 ] ) ),;
Details->( DbGoTo( o:oTreeItem:Cargo[ 2 ] ) ) ) }
oDlg:oClient = oBrw
ACTIVATE DIALOG oDlg CENTERED ;
ON INIT BuildBar( oDlg, oBrw )
return nil
function BuildBar( oDlg, oBrw )
local oBar
DEFINE BUTTONBAR oBar OF oDlg SIZE 50, 50 2007
DEFINE BUTTON OF oBar PROMPT "Task" RESOURCE "add" ;
ACTION ( Tasks->( DbAppend() ), Details->( DbAppend() ),;
Details->Task_id := Tasks->Id, Details->Date := Date(),;
Details->From := "09:00", Details->To := "11:00",;
oBrw:oTree := BuildTree(), oBrw:Refresh() )
DEFINE BUTTON OF oBar PROMPT "Detail" RESOURCE "add" ;
ACTION ( Tasks->( DbGoTo( If( Len( oBrw:oTreeItem:Cargo ) == 2,;
oBrw:oTreeItem:Cargo[ 2 ], oBrw:oTreeItem:Cargo[ 3 ] ) ) ),;
Details->( DbAppend() ), Details->task_id := Tasks->id,;
Details->Date := Date(), Details->From := "09:00",;
Details->To := "11:00",;
oBrw:oTree := BuildTree(), oBrw:Refresh() )
DEFINE BUTTON OF oBar PROMPT "Edit" RESOURCE "edit" ACTION oBrw:Edit()
DEFINE BUTTON OF oBar PROMPT "Del" RESOURCE "del"
oDlg:Resize()
return .T.
function BuildTree()
local oTree, nRecNo := Tasks->( RecNo() )
if Tasks->( RecCount() ) > 0
TREE oTree
Details->( DbGoTop() )
Tasks->( DbGoTop() )
while ! Tasks->( Eof() )
TREEITEM tasks->Task CARGO { "task", Tasks->( RecNo() ) }
if Details->( RecCount() ) > 0
TREE
while Details->Task_id == tasks->id .and. ! Details->( Eof() )
TREEITEM "Date: " + DToC( Details->Date ) + ;
" - From: " + RTRim( Details->From ) + ;
" - To: " + RTrim( Details->To ) ;
CARGO { "detail", Details->( RecNo() ), Tasks->( RecNo() ) }
Details->( DbSkip() )
end
ENDTREE
endif
Tasks->( DbSkip() )
end
ENDTREE
Tasks->( DbGoTo( nRecNo ) )
else
TREE oTree
ENDTREE
endif
// oTree:OpenAll()
return oTree
function EditItem( oTreeItem, oBrw )
local nRec := oTreeItem:Cargo[ 2 ], oDlg
local nBrwPos := oBrw:nRowSel
if oTreeItem:Cargo[ 1 ] == "detail"
DEFINE DIALOG oDlg SIZE 400, 220 PIXEL TRUEPIXEL TITLE "Edit detail"
Details->( DbGoTo( nRec ) )
@ 1, 2 SAY "Date:" OF oDlg
@ 1, 6 GET Details->Date PICTURE "9999-99-99" OF oDlg
@ 3.2, 2 SAY "From:" OF oDlg
@ 3.5, 6 GET Details->From PICTURE "99:99" OF oDlg
@ 5.3, 2 SAY "To:" OF oDlg
@ 5.9, 6 GET Details->To PICTURE "99:99" OF oDlg
@ 10, 14 BUTTON "OK" OF oDlg SIZE 80, 25 ;
ACTION ( Details->( DbCommit() ), oDlg:End(),;
oBrw:oTree := BuildTree(), oBrw:nRowSel := nBrwPos, oBrw:Refresh() )
@ 10, 34 BUTTON "Cancel" OF oDlg SIZE 80, 25 ACTION oDlg:End()
ACTIVATE DIALOG oDlg CENTERED
else
DEFINE DIALOG oDlg SIZE 400, 220 PIXEL TRUEPIXEL TITLE "Edit task"
Tasks->( DbGoTo( nRec ) )
@ 1, 2 SAY "Task:" OF oDlg
@ 1, 6 GET Tasks->Task SIZE 340, 20 OF oDlg
@ 10, 14 BUTTON "OK" OF oDlg SIZE 80, 25 ;
ACTION ( Tasks->( DbCommit() ), oDlg:End(),;
oBrw:oTree := BuildTree(), oBrw:Refresh() )
@ 10, 34 BUTTON "Cancel" OF oDlg SIZE 80, 25 ACTION oDlg:End()
ACTIVATE DIALOG oDlg CENTERED
endif
return nildetlef.rc
add BITMAP "../../../bitmaps/plus.bmp"
edit BITMAP "../../../bitmaps/32x32/edit.bmp"
del BITMAP "../../../bitmaps/delete2.bmp"Hello Antonio.
"I’ve been retired for some years now and only do a little programming as a hobby.
But every time, I’m amazed by the great helpfulness in this forum. :D
Please, one question:
I tried
oBmp1 := LoadBitmap( GetResources(), "folder" )
oBmp2 := LoadBitmap( GetResources(), "folder2" )
oBmp3 := LoadBitmap( GetResources(), "go" )
oImageList := TImageList():New()
oImageList:Add( oBmp1 )
oImageList:Add( oBmp2 )
oImageList:Add( oBmp3 )This gives me the error
Error BASE/1004 Class: 'NUMERIC' has no exported method: HBITMAP
Args:
[ 1] = N 0
How can i create the imagelist for the tree with bitmaps from a resource file?
Thanks, Detlef
Detlef wrote:oBmp1 := LoadBitmap( GetResources(), "folder" ) oBmp2 := LoadBitmap( GetResources(), "folder2" ) oBmp3 := LoadBitmap( GetResources(), "go" ) oImageList := TImageList():New() oImageList:Add( oBmp1 ) oImageList:Add( oBmp2 ) oImageList:Add( oBmp3 )
Try:
oBmp1 := TImage():Define( "folder" )
...
Hello Enrico,
thanks for your suggest.
I tried it but unfortunately I get an error :
Called from: source\rtl\tobject.prg => TLINKLIST:ERROR( 0 )
Called from: source\rtl\tobject.prg => TLINKLIST:MSGNOTFOUND( 0 )
Called from: source\rtl\tobject.prg => TLINKLIST:SETIMAGELIST( 0 )
Can I see the new code you are trying?
Hi Enrico,
thanks for jumping in.
FUNCTION Main()
LOCAL oDlg, oBmp1, oBmp2, oBmp3, oImageList, oBrw, oTree
RddSetDefault( "DBFCDX" )
SET DATE GERMAN
xbrNumFormat( "E", .t. ) // "E" for European, "A" for American and others
// .t. for showing thousand separators
OpenDbfs()
oImageList := TImageList():New()
oBmp1 := TImage():Define( "folder" )
oBmp2 := TImage():Define( "folder2" )
oBmp3 := TImage():Define( "go" )
oImageList:Add( oBmp1 )
oImageList:Add( oBmp2 )
oImageList:Add( oBmp3 )
oTree := BuildTree()
oTree:SetImageList( oImageList )
DEFINE DIALOG oDlg NAME "DLG_MAIN"
REDEFINE XBROWSE oBrw ID 10 OF oDlg LINES CELL
oBrw:SetTree( oTree )
oBrw:nMarqueeStyle = MARQSTYLE_HIGHLROW
// --- Buttons -----------------------------------------------------
REDEFINE BUTTON oBtnTaskNew ID 20 OF oDlg ACTION TaskEdit( .t. )
REDEFINE BUTTON oBtnTaskEdit ID 30 OF oDlg ACTION TaskEdit( .f. )
REDEFINE BUTTON oBtnTaskDelete ID 40 OF oDlg ACTION TaskDelete()
REDEFINE BUTTON oBtnExport ID 50 OF oDlg ACTION ExportCsv()
REDEFINE BUTTON ID 60 OF oDlg ACTION oDlg:End()
ACTIVATE DIALOG oDlg CENTER
tsk->( DbCloseArea() )
trm->( DbCloseArea() )
RETURN NILand
STATIC FUNCTION BuildTree()
//-------------------------
LOCAL oTree, nRecNo := tsk->( RecNo() )
if tsk->( RecCount() ) > 0
trm->( DbGoTop() )
tsk->( DbGoTop() )
TREE oTree BITMAPS
while ! tsk->( Eof() )
TREEITEM tsk->Task CARGO { "task", tsk->( RecNo() ) }
if trm->( RecCount() ) > 0
TREE
while trm->Task_id == tsk->id .and. ! trm->( Eof() )
TREEITEM "Date: " + DToC( trm->Date ) + ;
" - From: " + RTRim( trm->From ) + ;
" - To: " + RTrim( trm->To ) ;
CARGO { "detail", trm->( RecNo() ) }
trm->( DbSkip() )
end
ENDTREE
endif
tsk->( DbSkip() )
end
ENDTREE
tsk->( DbGoTo( nRecNo ) )
else
TREE oTree
ENDTREE
endif
return oTreeYou're asking about the difference between two tree control implementations in the FiveWin framework: one using
The custom tree implementation in
Yes, image lists work with both implementations, but differently:
The Windows API
Example usage: 0-cite-10
The custom implementation uses bitmap arrays instead of image lists. You pass bitmaps via the
Example usage: 0-cite-13
The Windows API
Wiki pages you might want to explore:
File: source/classes/ttreevie.prg (L42-48)
#define TVS_HASBUTTONS 1
#define TVS_HASLINES 2
#define TVS_LINESATROOT 4
#define TVS_SHOWSELALWAYS 32 // 0x0020
#define TVS_DISABLEDRAGDROP 16 // 0x0010
#define TVS_CHECKBOXES 256 // 0x0100
#define TVS_EDITLABELS 8File: source/classes/ttreevie.prg (L50-61)
#define CTRL_NAME "SysTreeView32"
//----------------------------------------------------------------------------//
CLASS TTreeView FROM TControl
DATA aItems
DATA oImageList
DATA bChanged
DATA bExpanded
DATA hEditFile: source/classes/ttreevie.prg (L125-125)
METHOD SetImageList( oImageList )File: samples/trees/treeview.prg (L43-53)
CLASS TTreeView FROM TControl
CLASSDATA lRegistered AS LOGICAL
DATA RootLink, nIndent, aBitmaps, aMasks, oItem
DATA oEditTimer, lEdit, oTipTimer
DATA nTreeStyle
METHOD New( nRow, nCol, nWidth, nHeight, oWnd, acBitmaps, acMasks, ;
bChange, bDblClick, bValid, nHelpID, ;
nClrFore, nClrBack, oFont, cMsg, bWhen, lPixel, nTreeStyle ) CONSTRUCTORFile: samples/trees/treeview.prg (L62-62)
METHOD cToChar() INLINE Super:cToChar( "LISTBOX" )File: samples/trees/treeview.prg (L126-126)
METHOD SetBitmaps( acBitmaps )File: samples/trees/treeview.prg (L183-186)
::nStyle = nOr( WS_CHILD, WS_VISIBLE, WS_BORDER, WS_TABSTOP, ;
WS_VSCROLL, WS_HSCROLL, ;
LBS_NOTIFY, LBS_OWNERDRAWVARIABLE, ;
LBS_NOINTEGRALHEIGHT, LBS_NOREDRAW )File: source/winapi/treeview.c (L100-109)
HB_FUNC( TVSETIMAGELIST ) // ( hWnd, hImageList, nType )
{
#ifndef _WIN64
hb_retnl( ( LONG ) TreeView_SetImageList( ( HWND ) hb_parnl( 1 ),
( HIMAGELIST ) hb_parnl( 2 ), hb_parnl( 3 ) ) );
#else
hb_retnll( ( LONGLONG ) TreeView_SetImageList( ( HWND ) hb_parnll( 1 ),
( HIMAGELIST ) hb_parnll( 2 ), hb_parnl( 3 ) ) );
#endif
}File: samples/test/testtree.prg (L32-44)
oImageList = TImageList():New()
oBmp1 = TBitmap():Define( "folder",, oWnd )
oBmp2 = TBitmap():Define( "fldMask",, oWnd )
oImageList:Add( oBmp1, oBmp2 )
oTree = TTreeView():New( 2, 0, oWnd )
oTree:bChanged = { || oWnd:SetText( If( oTree:GetSelected():GetParent() != nil,;
oTree:GetSelected():GetParent():cPrompt + " + ", "" ) + ;
oTree:GetSelText() ) }
oTree:SetImageList( oImageList )File: samples/test/testtre3.prg (L52-63)
oImageList := TImageList():New() // imagelist items are zero-based!
oImageList:Add( TBitmap():Define( "folder",, oChild ), ; // nImage == 0 (default if not specified)
TBitmap():Define( "fldMask",, oChild ) )
oImageList:Add( TBitmap():Define( "form",, oChild ), ; // nImage == 1
TBitmap():Define( "frmMask",, oChild ) )
oImageList:Add( TBitmap():Define( "icon",, oChild ),; // nImage == 2
TBitmap():Define( "icoMask",, oChild ) )
oImageList:Add( TBitmap():Define( "bitmap",, oChild ),; // nImage == 4
TBitmap():Define( "bmpMask",, oChild ) )
oTree := TTreeView():New( 2, 0, oChild )File: docs/reference/classes/TTreeView.md (L1-11)
# TTreeView Class
The `TTreeView` class provides a comprehensive implementation of a tree view control that displays hierarchical data in a collapsible tree structure. It supports advanced features including checkboxes, editable labels, custom images, and extensive event handling.
**Source File:** [source/classes/ttreevie.prg](../../../source/classes/ttreevie.prg)
## Overview
The `TTreeView` class encapsulates the Windows TreeView control, providing a high-level interface for managing hierarchical data structures. As a subclass of `TControl`, it inherits all standard control functionality while adding specialized behavior for tree navigation, item management, and user interaction.
Tree views are essential UI components for displaying hierarchical data such as file systems, organizational charts, navigation menus, and structured data with parent-child relationships.Your oTree is not a TTreeView object. So you can't use the methods of TTreeView class. With TLinkList (that's what you are using) you have to use the RESOURCE clause of TREEITEM command:
TREEITEM...
RESOURCE "folder"
...