Delphi操作XML(四)

以下引自万一：

关于NativeXML的编辑操作：

SourceURL:http://www.cnblogs.com/del/archive/2011/03/25/1995863.htmlXml (10)锛氱紪杈� - 涓囦竴 - 鍗氬鍥�

uses NativeXml;

var xml: TNativeXml;

const
xmlStr = '<?xml version="1.0" encoding="UTF-8"?>' +
'<List>' +
'<item ID="No.1" age="11">寮犱笁</item>' +
'<item ID="No.2" age="22">鏉庡洓</item>' +
'<item ID="No.3" age="33">鐜嬩簲</item>' +
'</List>';

procedure TForm1.FormCreate(Sender: TObject);
begin
xml := TNativeXml.Create(Self);
xml.XmlFormat := xfReadable;
xml.ReadFromString(xmlStr);     {!}
Memo1.Text := xml.WriteToString;
end;
{***************************************
<?xml version="1.0" encoding="UTF-8"?>
<List>
<item ID="No.1" age="11">寮犱笁</item>
<item ID="No.2" age="22">鏉庡洓</item>
<item ID="No.3" age="33">鐜嬩簲</item>
</List>
*****************************************}

{鎻掑叆銆佸垹闄
procedure TForm1.Button2Click(Sender: TObject);
begin
xml.ReadFromString(xmlStr);
xml.Root.NodeInsert(1, xml.NodeNewText('item', '璧靛叚'));
xml.Root.NodeDelete(xml.Root.NodeCount - 1);
Memo1.Text := xml.WriteToString;
end;
{***************************************
<?xml version="1.0" encoding="UTF-8"?>
<List>
<item ID="No.1" age="11">寮犱笁</item>
<item>璧靛叚</item>
<item ID="No.2" age="22">鏉庡洓</item>
</List>
*****************************************}

{绉婚櫎}
procedure TForm1.Button3Click(Sender: TObject);
begin
xml.ReadFromString(xmlStr);
xml.Root.NodeRemove(xml.Root[0]);
Memo1.Text := xml.WriteToString;
end;
{***************************************
<?xml version="1.0" encoding="UTF-8"?>
<List>
<item ID="No.2" age="22">鏉庡洓</item>
<item ID="No.3" age="33">鐜嬩簲</item>
</List>
*****************************************}

{浜ゆ崲}
procedure TForm1.Button4Click(Sender: TObject);
begin
xml.ReadFromString(xmlStr);
xml.Root.NodeExchange(0, 1);
Memo1.Text := xml.WriteToString;
end;
{***************************************
<?xml version="1.0" encoding="UTF-8"?>
<List>
<item ID="No.2" age="22">鏉庡洓</item>
<item ID="No.1" age="11">寮犱笁</item>
<item ID="No.3" age="33">鐜嬩簲</item>
</List>
*****************************************}

{鎻愬彇}
procedure TForm1.Button5Click(Sender: TObject);
var
node: TXmlNode;
begin
xml.ReadFromString(xmlStr);
node := xml.Root.NodeExtract(xml.Root[1]);
Memo1.Text := node.WriteToString;
Memo1.Lines.Add('---------------------------------------');
Memo1.Lines.Add(xml.WriteToString);
end;
{***************************************
<item ID="No.2" age="22">鏉庡洓</item>
---------------------------------------
<?xml version="1.0" encoding="UTF-8"?>
<List>
<item ID="No.1" age="11">寮犱笁</item>
<item ID="No.3" age="33">鐜嬩簲</item>
</List>
*****************************************}

{鑾峰彇浣嶇疆}
procedure TForm1.Button6Click(Sender: TObject);
var
n1,n2: Integer;
begin
xml.ReadFromString(xmlStr);

n1 := xml.Root.NodeIndexOf(xml.Root[xml.Root.NodeCount-1]);
ShowMessage(IntToStr(n1)); //2

n2 := xml.Root.NodeIndexOf(xml.Root[xml.Root.NodeCount]);
ShowMessage(IntToStr(n2)); //-1
end;

procedure TForm1.Button7Click(Sender: TObject);
var
node: TXmlNode;
begin
xml.ReadFromString(xmlStr);

node := xml.Root.NodeFindOrCreate('item');
ShowMessage(node.WriteToString); //<item ID="No.1" age="11">寮犱笁</item>

node := xml.Root.NodeFindOrCreate('寮犱笁');
ShowMessage(node.WriteToString); //<寮犱笁/>
Memo1.Text := xml.WriteToString;
end;
{***************************************
<?xml version="1.0" encoding="UTF-8"?>
<List>
<item ID="No.1" age="11">寮犱笁</item>
<item ID="No.2" age="22">鏉庡洓</item>
<item ID="No.3" age="33">鐜嬩簲</item>
<寮犱笁/>
</List>
*****************************************}

procedure TForm1.Button8Click(Sender: TObject);
var
node: TXmlNode;
begin
xml.ReadFromString(xmlStr);
node := xml.Root[0];
node.Clear;
Memo1.Text := xml.WriteToString;
{***************************************
<?xml version="1.0" encoding="UTF-8"?>
<List>
<item/>
<item ID="No.2" age="22">鏉庡洓</item>
<item ID="No.3" age="33">鐜嬩簲</item>
</List>
*****************************************}
xml.Root.DeleteEmptyNodes;
Memo1.Lines.Add('---------------------------------------');
Memo1.Lines.Add(xml.WriteToString);
{***************************************
<?xml version="1.0" encoding="UTF-8"?>
<List>
<item ID="No.2" age="22">鏉庡洓</item>
<item ID="No.3" age="33">鐜嬩簲</item>
</List>
*****************************************}
xml.Root.Clear;
Memo1.Lines.Add('---------------------------------------');
Memo1.Lines.Add(xml.WriteToString);
{***************************************
<?xml version="1.0" encoding="UTF-8"?>
<List/>
*****************************************}
xml.Clear;
Memo1.Lines.Add('---------------------------------------');
Memo1.Lines.Add(xml.WriteToString);
{***************************************

*****************************************}
end;