Delphi 中的 XMLDocument 类详解(14) - 遍历 XML 文件

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;

    procedure Button1Click(Sender: TObject);

    procedure Button2Click(Sender: TObject);

  end;



var

  Form1: TForm1;



implementation



{$R *.dfm}





//读取 xml 的函数

{

  功能1: 传入一个节点参数, 返回节点及其包含的所有内容;

  功能2: 排除了空节点.

}

function ReadXml(node: IXMLNode): string;

var

  nodeList,attrList: IXMLNodeList;

  str,strName,strValue: string;

  i: Integer;

begin

  Result := '';

  if not node.HasChildNodes then Exit;



  attrList := node.AttributeNodes;      {根节点的属性列表}

  nodeList := node.ChildNodes;          {根节点下的子节点列表}



  str := '<' + node.NodeName;



  {先读取属性}

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

  begin

    strName := attrList[i].NodeName;

    strValue := attrList[i].NodeValue;

    str := str + ' ' + strName + '=' + AnsiQuotedStr(strValue, '"');

  end;

  str := str + '>' + sLineBreak; {sLineBreak 是常量, 相当于 #13#10}



  {读取子节点}

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

  begin

    strName := nodeList[i].NodeName;

    if nodeList[i].IsTextElement then

    begin

      strValue := nodeList[i].NodeValue;

      str := str + '<' + strName + '>' + strValue + '</' + strName + '>' + sLineBreak;

    end else if nodeList[i].HasChildNodes then

    begin

      str := str + ReadXml(nodeList[i]);               {这是最关键的递归调用}

      str := str + '</' + strName + '>' + sLineBreak;  {封口}

    end;

  end;



  str := str + '</' + node.NodeName + '>'; {封口}



  Result := str;

end;





//调用测试(1):

procedure TForm1.Button1Click(Sender: TObject);

var

  str,s1,s2: string;

begin

  XMLDocument1.LoadFromFile('c:\temp\test.xml');

  {必须用万一提供的 xml 测试文件, 才能有相同的返回值}





  {读取文件头}

  s1 := AnsiQuotedStr(XMLDocument1.Version, '"');  {读出版本, 并添加双引号}

  s2 := AnsiQuotedStr(XMLDocument1.Encoding, '"'); {读出字符集, 并添加双引号}

  str := Format('<?xml version=%s encoding=%s?>',[s1,s2]); {这就是文件头了}



  str := str + sLineBreak + ReadXml(XMLDocument1.DocumentElement);



  ShowMessage(str); {返回 xml 包含问头在内的所有内容}

end;





//调用测试(2)

procedure TForm1.Button2Click(Sender: TObject);

var

  str: string;

  node: IXMLNode;

begin

  XMLDocument1.LoadFromFile('c:\temp\test.xml');



  node := XMLDocument1.DocumentElement.ChildNodes[0];



  str := ReadXml(node);



  ShowMessage(str); {返回返回根节点下第一个子节点的所有内容}

end;



end.