Delphi中dxTreelist控件的使用

Delphi中dxTreelist控件的使用

最近公司项目中用到dxTreelist控件，以前没怎么用过这个控件，该控件比TreeView功能更强大，要完全掌握还真不容易，下面是我个人做的一个Demo，对该控件进行增删改遍历操作，以便自己以后忘了使用方法随时可以查吧。

1.首先新建一个数据库。

打开SQL Server2005，新建数据库TreeTest，新建表DeviceTab，表的字段设计如下:

2.新建Delphi应用程序

选择File-New-Application新建应用程序，File-New-Data Module，新建一个数据库模块，添加TADOConnection和TImageList控件,设置ADOConnection 的LoginPrompt为false，给ImageList控件添加7个图片,该数据模块的Create 事件代码如下:

procedure Tdm.DataModuleCreate(Sender: TObject);

begin

if not con1.Connected then

begin

//设置连接字符串

con1.ConnectionString:='Provider=SQLOLEDB.1;Password=123456;Persi st Security Info=True;User ID=sa;Initial Catalog=TreeList;Data

Source=ZH\SQLEXPRESS;';

con1.Open; //打开数据库连接

end;

end;

在窗体上放置dxTreeList控件和四个Button控件以及一个Timer控件设置Timer控件的Interval属性为100,各按钮相关事件及源码如下：

unit Main;

interface

uses

Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, dxExEdtr, dxCntner, dxTL, dxTLClms,ADODB, Menus, cxLookAndFeelPainters, StdCtrls, cxButtons, ExtCtrls;

type

TfrmTree = class(TForm)

dxTreeList1: TdxTreeList;

btnAddNode: TcxButton;

btnDelNode: TcxButton;

btnUpdate: TcxButton;

btnbl: TcxButton;

tmr1: TTimer;

procedure btnblClick(Sender: TObject);

procedure btnAddNodeClick(Sender: TObject);

procedure btnDelNodeClick(Sender: TObject);

procedure btnUpdateClick(Sender: TObject);

procedure tmr1Timer(Sender: TObject);

procedure FormDestroy(Sender: TObject);

private

{ Private declarations }

public

{ Public declarations }

procedure CreateColumn(tree:TdxTreeList;list:TStrings);

procedure CreateImageColumn(tree:TdxTreeList;Image:TImageList);

procedure

FillTree(node:TdxTreeListNode;pid:Integer;con:TADOConnection);

function GetMaxId(con:TADOConnection):Integer;

procedure DelTree(pid:Integer;con:TADOConnection);

procedure UpdateTree(newname:string;id:Integer;con:TADOConnection);

function GetCount(tree:TdxTreeList):Integer;

end;

var

frmTree: TfrmTree;

implementation

{$R *.dfm}

uses unitDM;

var

list:TStrings;

procedure TfrmTree.CreateColumn(tree:TdxTreeList;list:TStrings); //动态创建dxTreeList的列

var

i:Integer;

col:TdxTreeListColumn;

begin

for i:=0 to list.Count-1 do

begin

col:=tree.CreateColumn(TdxTreeListMaskColumn);

col.Caption:=list[i]; //显示标题

col.ColIndex:=i; //列索引

https://www.sodocs.net/doc/1317703951.html,:=list[i]; //列标识

col.Width:=90+10*i; //列宽

end;

end;

procedure

TfrmTree.CreateImageColumn(tree:TdxTreeList;Image:TImageList);//创建带图片的列

var

col:TdxTreeListColumn;

i:Integer;

begin

col:=tree.CreateColumn(TdxTreeListImageColumn);

col.Width:=50;

https://www.sodocs.net/doc/1317703951.html,:='img';

TdxTreeListImageColumn(col).Images:=Image;

for i:=0 to image.Count-1 do //关联图片

begin

TdxTreeListImageColumn(col).ImageIndexes.Add(IntToStr(i));

TdxTreeListImageColumn(col).Values.Add(IntToStr(i));

end;

end;

procedure TfrmTree.FillTree(node: TdxTreeListNode; pid:

Integer;con:TADOConnection);//构造树

var

tmpnode:TdxTreeListNode;

ADOQuery:TADOQuery;

begin

ADOQuery:=TADOQuery.Create(nil);

try

ADOQuery.Connection:=con;

ADOQuery.Close;

ADOQuery.SQL.Clear;

ADOQuery.SQL.Text:='select * from DeviceTab where pid='+Inttostr(pid);

ADOQuery.Open;

with ADOQuery do

begin

First;

while not Eof do

begin

if node=nil then

tmpnode:=dxTreeList1.Add //添加根节点

else

tmpnode:=node.AddChild; //添加子节点

pid:=FieldByName('id').AsInteger;

tmpnode.Strings[0]:=IntToStr(pid);

tmpnode.Strings[1]:=FieldByName('pid').AsString;

tmpnode.Strings[2]:=FieldByName('aName').AsString;

tmpnode.Strings[3]:=IntToStr(tmpnode.Level);

tmpnode.ImageIndex:=tmpnode.Level;

tmpnode.SelectedIndex:=tmpnode.Level;

FillTree(tmpnode,pid,con); //递归添加子节点

Next;

end;

end;

finally

ADOQuery.Free;

end;

end;

procedure TfrmTree.btnblClick(Sender: TObject); //遍历子节点

var

node,tmpnode:TdxTreeListNode;

i:Integer;

str:string;

begin

if dxTreeList1.Count=0 then Exit;

node:=dxTreeList1.FocusedNode; //获取焦点的节点

for i:=0 to dxTreeList1.ColumnCount-1 do

str:=str+node.Strings[i]+';';

ShowMessage(str);

tmpnode:=node.GetFirstChild; //获取第一个子节点

while tmpnode<>nil do

begin

str:=';

for i:=0 to dxTreeList1.ColumnCount-1 do

str:=str+tmpnode.Strings[i]+';';

ShowMessage(str);

//if tmpnode=node.GetLastChild then break;

if (tmpnode=node.GetLastChild) and (not tmpNode.HasChildren) then break; //判断是否为最后一个子节点是终止循环

tmpnode:=tmpnode.GetNext; //获取下一个节点

end;

end;

procedure TfrmTree.btnAddNodeClick(Sender: TObject); //添加节点

var

node:TdxTreeListNode;

i:Integer;

idindex,pidIndex,anameindex,imgIndex:Integer;

id,pid:integer;

aname:string;

qry:TADOQuery;

IsExist:Boolean;

begin

aname:=';

pid:=0;

for i:=0 to dxTreeList1.ColumnCount-1 do

begin

if dxTreeList1.Columns[i].Name='aName' then

begin

anameindex:=i;

end

else if dxTreeList1.Columns[i].Name='id' then

begin

idindex:=i;

end

else if dxTreeList1.Columns[i].Name='pid' then

begin

pidIndex:=i;

end

else if dxTreeList1.Columns[i].Name='img' then

begin

imgIndex:=i;

end;

end;

if InputQuery('添加节点','请输入节点名称',aname) then begin

if dxTreeList1.Count=0 then

begin

node:=dxTreeList1.Add; //添加根节点

end

else

begin

node:=dxTreeList1.FocusedNode;

if node.Level=6 then

begin

ShowMessage('已经添加到节点极限');

exit;

end;

pid:=StrToIntDef(node.Strings[idindex],0);

node:=node.AddChild; //添加子节点

end;

id:=GetMaxId(dm.con1)+1;

node.Strings[idindex]:=IntToStr(id);

node.Strings[pidIndex]:=IntToStr(pid);

node.Strings[anameindex]:=aname;

node.Strings[imgIndex]:=IntToStr(node.Level);

node.ImageIndex:=node.Level;

node.SelectedIndex:=node.Level;

try

qry:=TADOQuery.Create(nil);

qry.Connection:=dm.con1;

qry.Close;

qry.SQL.Clear;

qry.SQL.Text:='insert into DeviceTab

values('+inttostr(id)+','+Inttostr(pid)+','+QuotedStr(aname)+')';

qry.ExecSQL;

finally

qry.Free;

end;

end;

end;

function TfrmTree.GetMaxId(con: TADOConnection): Integer; //获取最大ID值var

qry:TADOQuery;

begin

try

qry:=TADOQuery.Create(nil);

qry.Connection:=con;

with qry do

begin

close;

sql.Clear;

SQL.Add('select Max(id) as mid from DeviceTab');

Open;

First;

Result:=qry.FieldByName('mid').AsInteger;

end;

finally

qry.Free;

end;

end;

procedure TfrmTree.btnDelNodeClick(Sender: TObject); //删除节点

var

node:TdxTreeListNode;

i,aid:integer;

begin

if dxTreeList1.Count=0 then

begin

ShowMessage('没有要删除的节点');

Exit;

end

else

begin

node:=dxTreeList1.FocusedNode;

if MessageBox(Self.Handle,PChar('确定要删除该节点及其所有的子节点吗?'),PChar('删除提示'),MB_OKCANCEL)<>IdOK then Exit;

if node.HasChildren then node.DeleteChildren; //删除子节点

for i:=0 to dxTreeList1.ColumnCount-1 do

begin

if dxTreeList1.Columns[i].Name='id' then

begin

aid:=i;

Break;

end;

DelTree(StrToIntDef(node.Strings[aid],0),dm.con1);

node.Free;

end;

end;

procedure TfrmTree.DelTree(pid: Integer;con: TADOConnection); //删除数据库节点记录

var

tmpnode:TdxTreeListNode;

ADOQuery:TADOQuery;

begin

ADOQuery:=TADOQuery.Create(nil);

try

ADOQuery.Connection:=con;

with ADOQuery do

begin

Close;

SQL.Clear;

SQL.Text:='delete from DeviceTab where id='+Inttostr(pid); //删除当前节点记录

ExecSQL;

end;

ADOQuery.Close;

ADOQuery.SQL.Clear;

ADOQuery.SQL.Text:='select * from DeviceTab where

pid='+Inttostr(pid); //查找子节点记录

ADOQuery.Open;

with ADOQuery do

begin

First;

while not Eof do

begin

DelTree(FieldByName('id').AsInteger,con); //递归删除下级记录

Next;

end;

finally

ADOQuery.Free;

end;

end;

procedure TfrmTree.btnUpdateClick(Sender: TObject); 修改var

node:TdxTreeListNode;

aname:string;

i,j,k,id:Integer;

IsExist:Boolean;

begin

IsExist:=False;

if dxTreeList1.Count=0 then

begin

ShowMessage('没有要修改的节点');

exit;

end

else

begin

dxTreeList1.BeginUpdate;

node:=dxTreeList1.FocusedNode;

for i:=0 to dxTreeList1.ColumnCount-1 do

begin

if dxTreeList1.Columns[i].Name='aName' then

begin

j:=i;

aname:=node.Strings[i];

Break;

end

else if dxTreeList1.Columns[i].Name='id' then

begin

k:=i;

id:=StrToIntDef(node.Strings[i],0);

end;

if InputQuery('修改节点','请输入修改后的节点名',aname) then begin

node.Strings[j]:=aname;

UpdateTree(aname,id,dm.con1);//更新数据库记录end;

end;

dxTreeList1.EndUpdate;

end;

procedure TfrmTree.UpdateTree(newname: string; id: Integer; con: TADOConnection);

var

qry:TADOQuery;

begin

qry :=TADOQuery.Create(nil);

try

with qry do

begin

Connection:=con;

Close;

SQL.Clear;

SQL.Text:='update DeviceTab set

aname='+Quotedstr(newname)+' where id='+Inttostr(id);

ExecSQL;

end;

finally

qry.Free;

end;

end;

procedure TfrmTree.tmr1Timer(Sender: TObject);

begin

tmr1.Enabled:=False;

list:=TStringList.Create;

dm.con1.GetFieldNames('DeviceTab',list); //获取表的字段名

CreateColumn(dxTreeList1,list);

CreateImageColumn(dxTreeList1,dm.il1);

dxTreeList1.BeginUpdate;

FillTree(nil,0,dm.con1);

dxTreeList1.EndUpdate;

end;

procedure TfrmTree.FormDestroy(Sender: TObject);

begin

list.Free;

if dm.con1.Connected then

dm.con1.Close;

end;

function TFrmTree.GetCount(tree:TdxTreeList):integer; //获取总的节点数var

node:TdxTreeListNode;

begin

Result:=0;

dxTreeList1.GotoFirst;

node:=dxTreeList1.Items[0];

while node<>nil do

begin

inc(Result);

node:=node.GetNext;

end;

end;

end.

3.运行效果

初始界面

添加节点后界面

删除节点后界面

修改节点后界面

节点遍历( 部分截图)

总结:dxTreelist控件的属性和方法还有许多，功能比TreeView更丰富，同时操作也更复杂，它没有treeview.items.count属性获取节点总数，它的每一个节点都是一个TdxTreeListNode节点，操作每个节点时用Strings或Values集合来赋值给节点的每一列，以后如果用到再深入研究一下，这个Demo足够一般的应用。