操作XML文件

unit UMain;

interface

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

type
  TForm1 = class(TForm)
    Button1: TButton;
    Button2: TButton;
    Button3: TButton;
    Memo1: TMemo;
    Button4: TButton;
    Button5: TButton;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
    procedure Button4Click(Sender: TObject);
    procedure Button5Click(Sender: TObject);
  private
      myXml:IXMLDocument;
      XmlRoot:IXMLNode;
      NodePos:IXMLNode;

      procedure SetMemo(value:String);
  public
  published
      Property FMemo:String Write SetMemo;
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}
procedure TForm1.SetMemo(value:String);
begin
    Memo1.Lines.Add(value);
    Memo1.Lines.Add('');
end;


//初始化
procedure TForm1.Button1Click(Sender: TObject);
var
    filePath:String;
begin
    myXml:=TXMLDocument.Create(nil); //创建时owner不能为nil，否则无法正常释放
    myXml.Active:=true;
    myXml.Version:='1.0';
    myXml.Encoding:='GB2312';
    filePath:=ExtractFilePath(Application.ExeName)+'MyXml.xml';
    myXml.LoadFromFile(filePath);
    FMemo:='初始化完成';
    {关于保存缩进
    myXml.NodeIndentStr:=#9;//指定缩进符，这里我用的是tab，也可以换成空格'    '               这里是4个空格
    myXml.Options:=xml.Options + [doNodeAutoIndent];//这一段是关键，如果不指定为doNodeAutoIndent，缩进是不会生效的  }
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
    myXml._Release;
end;

//获得节点及属性
procedure TForm1.Button3Click(Sender: TObject);
var
    str:String;
    nodeNum:Integer;
    i:Integer;

    noderef: IXMLDOMNodeRef;
begin
    //得到根节点
    XmlRoot:= myXml.DocumentElement;
    FMemo:='根节点的名字='+XmlRoot.NodeName;

    //当前节点下的子节点的数目
    nodeNum:=XmlRoot.ChildNodes.Count;
    str:='当前节点下的子点节数目为： '+IntToStr(nodeNum);
    for i:=0 to nodeNum-1 do
    begin
        str:=str+#13#10'子节点'+IntToStr(i+1)+'的名称='+XmlRoot.ChildNodes.Nodes[i].NodeName;
    end;
    FMemo:=str;

    //读某一节点的值
    NodePos:=XmlRoot.ChildNodes['hdr'].ChildNodes['sessionid'];
    FMemo:='hdr-->sessionid='+NodePos.NodeValue;

    //判断节点属性是否存在，并得到节点属性的值
    NodePos:=XmlRoot.ChildNodes['slia'];
    if NodePos.HasAttribute('ver1') then
        FMemo:='slia节点的ver属性为： '+NodePos.Attributes['ver']
    else
        FMemo:='节点属性不存在';

    //判断节点内容是否存在，及得到值
    NodePos:=XmlRoot.ChildNodes['hdr'].ChildNodes['sessionid'];
    if NodePos.IsTextElement then
        FMemo:='Text='+NodePos.Text
    else
        FMemo:='F';

    //遍历某节点的属性名称及值
    str:='';
    NodePos:=XmlRoot.ChildNodes['slia'].ChildNodes['pos'].ChildNodes['msid'];
    nodeNum:=NodePos.AttributeNodes.Count;
    for i:=0 to nodeNum-1 do
    begin
        str:=str+'     '+nodePos.AttributeNodes.Nodes[i].NodeName+'='+nodePos.AttributeNodes.Nodes[i].NodeValue;
    end;
    FMemo:=str;


    //根据属性值查找节点
    noderef := myXml.DocumentElement.DOMNode as IXMLDOMNodeRef;
    FMemo:='属性ID为101的节点内容：'+noderef.GetXMLDOMNode.selectSingleNode('slia/pos/NewNode[@id=''102'']').text;
   // FMemo:='属性ID为101的节点内容：'+NodePos.NodeValue;
end;


//添加节点及属性
procedure TForm1.Button4Click(Sender: TObject);
var
    filePath:String;
begin
    //为某一节点添加子节点
    XmlRoot:= myXml.DocumentElement.ChildNodes['slia'].ChildNodes['pos'].AddChild('NewNode33333');
    //添加属性并赋初值
    XmlRoot.Attributes['id']:='100';
    XmlRoot.Text:='测试';

    //添加完保存
    filePath:=ExtractFilePath(Application.ExeName)+'MyXml.xml';
    myXml.SaveToFile(filePath);
end;

//删除节点
procedure TForm1.Button5Click(Sender: TObject);
var
    filePath:String;
begin
    XmlRoot:= myXml.DocumentElement;
    NodePos:= XmlRoot.ChildNodes['slia'].ChildNodes['pos'].ChildNodes['NewNode33333'];
    NodePos.ParentNode.ChildNodes.Remove(NodePos);
    //删除完保存
    filePath:=ExtractFilePath(Application.ExeName)+'MyXml.xml';
    myXml.SaveToFile(filePath);
end;
end.