www.pudn.com > TreeView_Sample.rar > TreeUtils.pas

unit TreeUtils; 
 
interface 
uses 
  Windows, Messages, SysUtils, Variants, Classes, ComCtrls, DB, ADODB, 
  TreeFillThrd; //注意 
type 
  TTreeUtils = class 
    TreeView: TTreeView; 
    NData: TNodeData; 
    Conn: TADOConnection; 
    Query: TADOQuery; 
    constructor Create(ATree: TTreeView; AConn: TADOConnection; ATableName: string; 
      AFieldIndex: string = 'ID'; AFieldPID: string = 'PID'; 
      AFieldCaption: string = 'Caption'; ARootText: string = '我的目录'); 
    destructor Destroy; 
  private 
    TableName: string; 
    FieldIndex: string; 
    FieldPID: string; 
    FieldCaption: string; 
    RootText: string; 
    sqlStr, errStr: string; 
    function getMaxIndex: integer; 
    function execSQL(sqlStr: string; var errMsg: string): boolean; 
  public 
    //按照节点在数据库中的编号查找节点 
    function FindTreeNode(Tree: TTreeView; Index: integer): TTreeNode; 
    //删除子树 
    function DeleteTree(Node: TTreeNode): Boolean; 
    //查找节点在数据库中的数据 
    function getTreeNodeData(TreeNode: TTreeNode): TNodeData; 
    function getSelNodeIndex: integer; 
    function getSelNodeCaption: string; 
    //添加节点 
    function AddNode(ACaption: string = '新节点'; Index: integer = -1; ANode: TTreeNode = nil): Boolean; 
    function AddChildNode(ACaption: string = '新节点'; Index: integer = -1; ANode: TTreeNode = nil): Boolean; 
    //修改节点 
    function ModifyNodeCaption(NewCaption: string; Node: TTreeNode): boolean; 
    function ModifyNodePID(PID: integer; Node: TTreeNode): boolean; 
    //填充节点 
    procedure FillTree; 
  end; 
 
implementation 
//-------------------------------------------------------------- 
constructor TTreeUtils.Create(ATree: TTreeView; AConn: TADOConnection; ATableName: string; 
  AFieldIndex: string = 'ID'; AFieldPID: string = 'PID'; 
  AFieldCaption: string = 'Caption'; ARootText: string = '我的目录'); 
begin 
  TreeView := ATree; 
  Conn := AConn; 
  TableName := ATableName; 
  FieldIndex := AFieldIndex; 
  FieldPID := AFieldPID; 
  FieldCaption := AFieldCaption; 
  RootText := ARootText; 
  Query := TADOQuery.Create(nil); 
  Query.Connection := Conn; 
end; 
//-------------------------------------------------------------- 
destructor TTreeUtils.Destroy; 
begin 
  Query.Free; 
  inherited Destroy; 
end; 
//-------------------------------------------------------------- 
function TTreeUtils.FindTreeNode(Tree: TTreeView; Index: integer): TTreeNode; 
var i: integer; 
begin 
  Result := nil; 
  for i := 0 to Tree.Items.Count - 1 do 
    if PNodeData(Tree.Items.Item[i].Data)^.Index = Index then 
      Result := Tree.Items.Item[i]; 
end; 
//-------------------------------------------------------------- 
function TTreeUtils.DeleteTree(Node: TTreeNode): Boolean; 
  function DelTableFromIndex(index: integer): boolean; 
  var 
    sqlStr: string; 
    errSTr: string; 
  begin 
    Result := False; 
    SQLStr := 'Delete from ' + TableName + ' where ' + FieldIndex + ' = ' + IntToStr(index); 
    if execSQL(sqlStr, errStr) then Result := True; 
  end; 
  //------------------------------------------------------------ 
  function DelTreeFromDB(ParentID: integer): Boolean; 
  var Query: TADOQuery; 
  begin 
    Query := nil; 
    Result := False; 
    try 
      Query := TADOQuery.Create(nil); 
      Query.Connection := Conn; 
      Query.SQL.Text := 'select * from ' + TableName + ' where PID = ' + IntToStr(ParentID); 
      if Query.Active then Query.Close; 
      Query.Open; 
      while Query.Eof = False do 
      begin 
        DelTreeFromDB(Query.FieldValues[FieldIndex]); 
        Result := DelTableFromIndex(Query.FieldByName(FieldIndex).AsInteger); 
        Query.Next; 
      end; 
    finally 
      Query.Free; 
    end; 
    Result := DelTableFromIndex(ParentID); 
  end; 
  //------------------------------------------------------------ 
begin 
  Result := False; 
  if Node.AbsoluteIndex = 0 then 
  begin 
    raise Exception.Create('禁止删除根节点！'); 
    Exit; 
  end; 
  if DelTreeFromDB(PNodeData(Node.Data)^.Index) then 
  begin 
    TreeView.Items.Delete(Node); 
    Result := True; 
  end; 
end; 
//-------------------------------------------------------------- 
function TTreeUtils.getTreeNodeData(TreeNode: TTreeNode): TNodeData; 
begin 
  if TreeNode = nil then 
    Result := PNodeData(TreeView.Items.Item[0].Data)^ 
  else 
    Result := PNodeData(TreeNode.Data)^; 
end; 
//-------------------------------------------------------------- 
function TTreeUtils.getSelNodeIndex: integer; 
var PData: PNodeData; 
begin 
  Result := -1; 
  if TreeView.Selected = nil then Exit; 
  PData := PNodeData(TreeView.Selected.Data); 
  Result := PData^.Index; 
end; 
function TTreeUtils.getSelNodeCaption: string; 
var PData: PNodeData; 
begin 
  Result := ''; 
  if TreeView.Selected = nil then Exit; 
  PData := PNodeData(TreeView.Selected.Data); 
  Result := PData^.Caption; 
end; 
//-------------------------------------------------------------- 
function TTreeUtils.AddNode(ACaption: string = '新节点'; Index: integer = -1; 
  ANode: TTreeNode = nil): Boolean; 
var Node, NewNode: TTreeNode; 
  PData: PNodeData; 
begin 
  Result := True; 
  try 
    if ANode = nil then Node := TreeView.Selected 
    else Node := ANode; 
    New(PData); 
    PData^.Index := getMaxIndex + 1; 
    PData^.Caption := ACaption; 
    sqlStr := 'Insert into ' + TableName + ' (' + FieldIndex + ',' + FieldPID + 
      ',' + FieldCaption + ')' + ' values(' + 
      IntToStr(PData^.Index) + ','; 
    if Node = nil then Node := TreeView.Items.Item[0]; 
    if Node.Level = 0 then 
      sqlStr := sqlStr + '0,"' + ACaption + '")' 
    else 
      sqlStr := sqlStr + IntToStr(PNodeData(Node.Parent.Data)^.Index) + ',"' + ACaption + '")'; 
    if execSQL(sqlStr, errStr) then 
    begin 
      if Node.Level = 0 then 
        NewNode := TreeView.Items.AddChildObject(Node, ACaption, PData) 
      else NewNode := TreeView.Items.AddObject(Node, ACaption, PData); 
      NewNode.ImageIndex := 1; 
      NewNode.SelectedIndex := 2; 
    end; 
  except 
    Result := False; 
  end; 
end; 
//-------------------------------------------------------------- 
function TTreeUtils.AddChildNode(ACaption: string = '新节点'; 
  Index: integer = -1; ANode: TTreeNode = nil): Boolean; 
var Node, NewNode: TTreeNode; 
  PData: PNodeData; 
begin 
  Result := True; 
  try 
    if ANode = nil then Node := TreeView.Selected 
    else Node := ANode; 
    New(PData); 
    PData^.Index := getMaxIndex + 1; 
    PData^.Caption := ACaption; 
    sqlStr := 'Insert into ' + TableName + ' (' + FieldIndex + ',' + FieldPID + 
      ',' + FieldCaption + ')' + ' values(' + 
      IntToStr(PData^.Index) + ','; 
    if Node = nil then Node := TreeView.Items.Item[0]; 
    if Node.Level = 0 then 
      sqlStr := sqlStr + '0,"' + ACaption + '")' 
    else 
      sqlStr := sqlStr + IntToStr(PNodeData(Node.Data)^.Index) + ',"' + ACaption + '")'; 
    if execSQL(sqlStr, errStr) then 
    begin 
      NewNode := TreeView.Items.AddChildObject(Node, ACaption, PData); 
      NewNode.ImageIndex := 1; 
      NewNode.SelectedIndex := 2; 
    end; 
 
  except 
    Result := False; 
  end; 
end; 
//-------------------------------------------------------------- 
//执行SQL语言 
function TTreeUtils.execSQL(sqlStr: string; var errMsg: string): boolean; 
begin 
  result := false; 
  errMsg := '执行成功！'; 
  try 
    Query.SQL.Text := sqlStr; 
    if Query.Active then Query.Close; 
    Query.ExecSQL; 
    result := true; 
  except 
    on e: Exception do 
      errMsg := e.Message; 
  end; 
end; 
//------------------------------------------------------------------------------ 
function TTreeUtils.getMaxIndex: integer; 
var i: integer; 
  PNode: PNodeData; 
begin 
  Result := 0; 
  for i := 0 to TreeView.Items.Count - 1 do 
  begin 
    PNode := PNodeData(TreeView.Items.Item[i].Data); 
    if Result < PNode^.Index then 
      Result := PNode^.Index; 
  end; 
end; 
//------------------------------------------------------------------------------ 
procedure TTreeUtils.FillTree; 
var H: TTreeFill; 
begin 
  H := TTreeFill.Create(TreeView, Conn, TableName, RootText, FieldIndex, FieldPID, FieldCaption); 
end; 
//------------------------------------------------------------------------------ 
function TTreeUtils.ModifyNodeCaption(NewCaption: string; 
  Node: TTreeNode): boolean; 
begin 
  sqlStr := 'Update ' + TableName + ' set ' + FieldCaption + '="' + NewCaption + '" where ' 
    + FieldIndex + ' = ' + IntToStr(PNodeData(Node.Data)^.Index); 
  if execSQL(sqlStr, errStr) then 
  begin 
    Node.Text := NewCaption; 
    PNodeData(Node.Data)^.Caption := NewCaption; 
  end; 
end; 
//------------------------------------------------------------------------------ 
function TTreeUtils.ModifyNodePID(PID: integer; Node: TTreeNode): boolean; 
  function InChildNode(APID: integer; ANode: TTreeNode): boolean; 
  var loop, NStart, NEnd: integer; 
  begin 
    Result := False; 
    NStart := Node.AbsoluteIndex; 
    if Node.getNextSibling = nil then NEnd := TreeView.Items.Count - 1 
    else NEnd := Node.GetNextSibling.AbsoluteIndex; 
    for loop := NStart + 1 to NEnd - 1 do 
    begin 
      Result := Result or (PNodeData(TreeView.Items.Item[loop].Data)^.Index = PID); 
    end; 
  end; 
begin 
  Result := False; 
  //如果是根节点则忽略 
  if Node.AbsoluteIndex = 0 then Exit; 
  //如果PID不变则忽略 
  if PID = PNodeData(Node.Parent.Data)^.Index then Exit; 
  //如果父节点是自己也则忽略 
  if PID = PNodeData(Node.Data)^.Index then Exit; 
  //如果父节点编号是它其中一级子节点的编号，则忽略 
  if InChildNode(PID, Node) then Exit; 
  sqlStr := 'Update ' + TableName + ' set ' + FieldPID + '="' + IntToStr(PID) + '" where ' 
    + FieldIndex + ' = ' + IntToStr(PNodeData(Node.Data)^.Index); 
  if execSQL(sqlStr, errStr) then Result := True; 
end; 
 
end.