// Continued
Void __fastcall tdbtreeview :: FillChildtreenodes (int ParentID, Ttreenode * Node, Bool Nest)
{/ Pack the child node with the specified value
TQuery * AQuery = New TQuery (this); // Create a data set control
ANSISUSTRING STRSQL, STRTEXT;
INT IID, IParentID;
Int iimageIndex, IselectedIndex;
TTREENODE * TREENODE;
TDBTREENODEDATA NODEDATA;
/ / Set the parameters of the data set
AQuery-> DatabaseName = (TTable *) (fdataLink-> DataSource-> Dataset) -> DatabaseName; // Setting Database Name
AQuery-> Close (); // Turns off the data set
AQuery-> SQL-> CLEAR (); // Clear the original SQL statement
strsql = "SELECT *" ((Ttable *) (fdataLink-> DataSource-> Dataset) -> Tablename "Where";
STRSQL = fparentidfield "=: pid";
AQuery-> SQL-> Add (strsql); // Specify a new SQL statement
AQuery-> parambyname ("pid") -> asinteger = ParentId;
AQuery-> Open (); // Open Data Set
this-> items-> beginupdate (); // Start updating DBTREEVIEW component display
While (! AQuery-> EOF) // Not until the end of the data set
{
Strtext = AQuery-> FieldByName (fdisplayfield) -> asstring; // get the display field content
IID = AQUERY-> FieldByName (fPrimaryIDfield) -> asinteger; // get the primary identification field content
iParentID = AQUERY-> FieldByName (fparentidfield) -> asinteger; // get the parent identification field content
Treenode = this-> items-> addchild (node, strtext); // Add the relevant data obtained above to the new node
IIMAGEINDEX = ISELECTEDINDEX = -1; // Set node bitmap and selection time bitmap
IF (FonsetImageIndex) FonsetImageIndex (this, IID, iParentID, Treenode-> Level, IIMAGEIDEX, ISELECTEDINDEX); // Trigger related events if setting up bitmap changes
Treenode-> ImageIndex = iimageIndex; // Set node bitmap and selected time bitmap
Treenode-> SELECTEDINDEX = ISELECTEDINDEX;
NodeData.id = IID; // Get the node master identity, the parent ID, and add a new node according to it
NodeData.parentId = iParentID;
AddDataTonode (Treenode, NodeData);
If (Nest) FillChildTreenodes (IID, TREENODE); // If the specified parameter NEST is TRUE, the recursive call is used to populate all sub-nodes.
AQuery-> Next (); // Move to the next record}
this-> items-> endupdate (); // End DBTREEVIEW component update
AQuery-> Close (); // Turns off the data set
Delete aquery; / / Delete temporary created data set controls
}
Void __fastcall tdbtreeview :: adddatatonode (Ttreenode * Node, TDBTREENODEDATA & DATA)
{// Add data to node
TDBTREENODEDATA * PDATA = New TDBTREENODEDATA;
* pdata = data;
Node-> Data = PDATA;
}
/ / -------------------------------------------------------------------------------------------- ---------------------------
TDBTREENODEDATA __FASTCALL TDBTREEVIEW :: getnodedata (ttreenode * node)
{// acquire the data of the specified node
Return * (TDBTREENODEDATA *) (Node-> DATA);
}
/ / -------------------------------------------------------------------------------------------- ---------------------------
Void __fastcall tdbtreeview :: loaded (void)
{// call the original LOAD method
TCUSTOMTREEVIEW :: loaded ();
/ * TODO: LOAD * /
}
/ / -------------------------------------------------------------------------------------------- ---------------------------
Void __fastcall tdbtreeview :: NOTIFICATION (Classes :: Tcomponent * Acomponent, Classes :: TOPERATION OPERATION)
{
// Event response
TCUSTOMTREEVIEW :: NOTIFICATION (Acomponent, Operation); // Call the original method
IF ((Operation == Opremove) && (ACOMPONENT == DataSource)) // If the operation is Opremove and the data connection is not empty and the specified component is a data source, then
DataSource = NULL; // Make the data source is empty
}
/ / -------------------------------------------------------------------------------------------- ---------------------------
Void __fastcall tdbtreeview :: Edit (Const tagtvitema & item)
{// Edit Node
TCUSTOMTREEVIEW :: Edit (item); // Call the original method
If (FallowModifyDB) // If you allow modification, then
{
TTREENODE * NODE;
Ansistring DatabaseName = ((Ttable *) (fdataLink-> DataSource-> Dataset) -> DatabaseName;
Ansistring Tablename = ((Ttable *) (fdataLink-> DataSource-> Dataset) -> TABLENAME;
TDBTREENODEDATA NODEDATA;
TQuery * AQuery = New TQuery (this); // Newly built a dataset
ANSISUSTRING STRSQL;
IF (item.State & TVIF_PARAM! = 0) Node = (Ttreenode *) (Item.lParam); Else Node = items-> getnode (item.hitem);
Nodedata = getnodedata (node);
strsql = "update" Tablename "set" fdisplayfield "=: newdisptext where" fprimaryidfield "=: id"; // Update the data set with the specified condition
AQuery-> Close (); // Turns off the data set
AQuery-> DatabaseName = DatabaseName; // Set database connection
AQuery-> SQL-> CLEAR (); // Clear the original SQL statement
AQuery-> sql-> add (strsql); // Add SQL statement
AQuery-> parambyname ("newdisptext") -> asstring = node-> text; // assigns the parameters in SQL
AQuery-> parambyname ("id") -> asinteger = nodedata.id;
AQuery-> execSql (); // Open Data Set
Delete aquery; / / Delete temporary created data set controls
}
}
/ / -------------------------------------------------------------------------------------------- ---------------------------
Void __fastcall tdbtreeview :: expand (ttreenode * node)
{// Expand the specified node
TCUSTOMTREEVIEW :: Expand (node); // Call the original method
TDBTREENODEDATA NODEDATA;
TTREENODE * ANODE;
For (anode = node-> getfirstchild (); anode; anode = node-> getNextChild (anode)) // Traverse the child node of the specified node
{
NodeData = getnodedata (anode); // get node data
If (anode-> count == 0) // If the node data is 0, the child node is filled.
Fillchildtreenodes (NodeData.ID, Anode);
}
}
/ / -------------------------------------------------------------------------------------------- ---------------------------
Void __fastcall tdbtreeview :: Keydown (Word & Key, Classes :: TshiftState Shift)
{
// Keyboard processing
TwinControl :: KeyDown (Key, Shift); // Call the original keyboard processing method
IF (key == vk_f2 && shift == tshiftState ()) // if it is Shift F2
{
/ * Handle 'F2' Key * /
IF (this-> selected! = null) // Edit the currently selected node
this-> selected-> edittext ();
}
}
/ / -------------------------------------------------------------------------------------------- ---------------------------
Void __fastcall tdbtreeview :: change (ttreenode * node) {// Handling node change event
TCUSTOMTREEVIEW :: Change (node); // Call the original method
Static ttreenode * OldNode = NULL;
TTREENODE * SELECTEDNODE = this-> SELECTED; / / Get selected node pointer
TDBTREENODEDATA NODEDATA;
TTable * atable = (ttable *) (fdataLink-> DataSource-> DataSet); // Specify a data set
IF (OldNode == SELECTEDNODE) RETURN; // If the old node is equal to the selected node, return directly
IF (atable == null) return; // If the data set is directly returned
IF (SELECTEDNODE == NULL) RETURN; // Return directly if there is no selected node
NodeData = getnodedata (selectedNode); / / get the specified node data
ATABLE-> setKey (); // Find data records as specified
ATABLE-> FieldByname (FPRIMARYIDFIELD) -> asinteger = nodedata.id;
ATABLE-> gotoKey ();
OldNode = SELECTEDNODE; // Old node is equal to the selected node
}
/ / -------------------------------------------------------------------------------------------- ---------------------------
Bool __fastcall tdbtreeview :: CustomDrawItem (Ttreenode * Node, TcustomDrawState Stage, Bool & PaintImages)
{
// Self-painted node
Bool result; // Call the original self-painted method
Result = TCUSTOMTREEVIEW :: CustomDrawItem (Node, State, Stage, PaintImages);
/ * Todo: ... * /
// TDBTREENODEDATA NODEDATA = GetNodedata (Node);
Return Result;
}
/ / -------------------------------------------------------------------------------------------- ---------------------------
Void __fastcall tdbtreeview :: fullxpand (void)
{// Expand all nodes
If (! Active) // If the dbtreeview is not an active state, an exception is thrown
Throw Exception ("DBTREEVIEW IS INACTIVE.");
this-> items-> beginupdate (); // Start updating DBTREEVIEW
ClearalLnodes (); // Clear all nodes
FillChildtreenodes (0, null, true); // Fill child nodes
this-> items-> endupdate (); // End Update
TCUSTOMTREEVIEW :: fullxpand (); // Call the original method to expand all nodes
}
/ / -------------------------------------------------------------------------------------------- ---------------------------
Void __fastcall tfieldnameproperty :: getValues (Classes :: TgetstrProc PROC)
{// get a field value
INT I;
TDBTreeView * AdbtreeView; AdbtreeView = (TDBTREEVIEW *) getcomponent (0);
IF (AdbtreeView-> DataSource! = null) // If the DBTREEVIEW data source is not empty, then
{// Traverse all fields and fill it into the relevant field properties
For (i = 0; i
Proc (AdbtreeView-> DataSource-> DataSet-> Fields-> Fields [i] -> fieldname);
}
Else
{/ / Otherwise throwing anomalies
Throw Exception ("Missing Datasource Property.");
}
}
TTYPEINFO * ANSISUSTRINGTYPEINFO (VOID)
{
// Define type information
TtypeInfo * TypeInfo = New TTYPEINFO;
TYPEINFO-> Name = "ANSISTRING";
TypeInfo-> Kind = tklstring;
Return TypeInfo;
}
"Seeing a DBTREEVIEW development summary"
