c++ builder 中的 XMLDocument 类详解(4) 攻取根目录下元素数

//---------------------------------------------------------------------------

#ifndef Unit1H
#define Unit1H
//---------------------------------------------------------------------------
#include <Classes.hpp>
#include <Controls.hpp>
#include <StdCtrls.hpp>
#include <Forms.hpp>
#include <msxmldom.hpp>
#include <XMLDoc.hpp>
#include <xmldom.hpp>
#include <XMLIntf.hpp>
//---------------------------------------------------------------------------
class TForm1 : public TForm
{
__published:	// IDE-managed Components
    TXMLDocument *XMLDocument1;
    TButton *btn_1;
    TButton *btn_2;
    TButton *btn_3;
    void __fastcall FormCreate(TObject *Sender);
    void __fastcall btn_1Click(TObject *Sender);
    void __fastcall btn_2Click(TObject *Sender);
    void __fastcall btn_3Click(TObject *Sender);
private:	// User declarations
public:		// User declarations
    __fastcall TForm1(TComponent* Owner);
};
//---------------------------------------------------------------------------
extern PACKAGE TForm1 *Form1;
//---------------------------------------------------------------------------
#endif

//---------------------------------------------------------------------------

#include <vcl.h>
#pragma hdrstop

#include "Unit1.h"
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"
TForm1 *Form1;
//---------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner)
    : TForm(Owner)
{
}
//---------------------------------------------------------------------------

void __fastcall TForm1::FormCreate(TObject *Sender)
{
    //打开
    XMLDocument1->LoadFromFile("D:\code\BCB\xml\test.xml");
}
//---------------------------------------------------------------------------

void __fastcall TForm1::btn_1Click(TObject *Sender)
{
    //第一种方法
    ShowMessage(IntToStr(XMLDocument1->DocumentElement->ChildNodes->Count));
}
//---------------------------------------------------------------------------
void __fastcall TForm1::btn_2Click(TObject *Sender)
{
    //第二种方法

    _di_IXMLNodeList nodeList;//定义一个节点列表对象

    //把根节点下面的结点赋值给节点列表对象
    nodeList=XMLDocument1->DocumentElement->ChildNodes;
    ShowMessage(IntToStr(nodeList->Count));
}
//---------------------------------------------------------------------------

void __fastcall TForm1::btn_3Click(TObject *Sender)
{
    //第三种方法

    _di_IXMLNode node;//定义一个节点对象
    _di_IXMLNodeList nodeList;//定义一个节点对象集

    //根节点也是一个节点, 把它赋给节点对象
    node=XMLDocument1->DocumentElement;
    nodeList=node->ChildNodes;
    ShowMessage(IntToStr(nodeList->Count));
}
//---------------------------------------------------------------------------