unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, xmldom, XMLIntf, msxmldom, XMLDoc, StdCtrls;

type
  TForm1 = class(TForm)
    XMLDocument1: TXMLDocument;
    Button1: TButton;
    Button2: TButton;
    Button3: TButton;
    procedure FormCreate(Sender: TObject);
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

//打开
procedure TForm1.FormCreate(Sender: TObject);
begin
  XMLDocument1.LoadFromFile('c:\temp\test.xml');
end;


//获取根目录下的元素数(1)
procedure TForm1.Button1Click(Sender: TObject);
begin
  ShowMessage(IntToStr(XMLDocument1.DocumentElement.ChildNodes.Count)); {4}
  {DocumentElement 是根节点}
  {ChildNodes 是节点包含的子节点的列表}
end;


//获取根目录下的元素数(2) 
procedure TForm1.Button2Click(Sender: TObject);
var
  nodeList: IXMLNodeList; {定义一个节点列表对象}
begin
  nodeList := XMLDocument1.DocumentElement.ChildNodes;
  {把根节点下的子节点列表赋给节点列表对象}

  ShowMessage(IntToStr(nodeList.Count)); {4}
end;


//获取根目录下的元素数(3) 
procedure TForm1.Button3Click(Sender: TObject);
var
  node: IXMLNode;         {定义一个节点对象}
  nodeList: IXMLNodeList; {定义一个节点列表对象}
begin
  node := XMLDocument1.DocumentElement;
  {根节点也是一个节点, 把它赋给节点对象}

  nodeList := node.ChildNodes;
  ShowMessage(IntToStr(nodeList.Count)); {4}
end;

end.