XML和对象属性互转的基类

2024-02-13 19:47:52

本人做了一个XML和对象属性互转的基类，现在放上来有兴趣拿去看一下，用法很简单，声明一个BaseConversion的子类，该子类与你想转换的对象相对应，然后覆盖基类的两个虚方法，然后在里面写元素与对象属性的转换即可以，废话少说了，还是看代码了，例子也懒得去写了，相信不会很难看懂的：

unit XMLConversion;

{*******************************************
* brief: XML和对象属性的转换
* autor: linzhenqun
* date: 2005-10-26
* email: linzhengqun@163.com
* blog: http://blog.csdn.net/linzhengqun
********************************************}

interface
uses
Classes, SysUtils, xmldom, XMLIntf, oxmldom, XMLDoc;

Type

TBaseConversion = class
protected
FXMLDoc: TXMLDocument;

(* 在ParenElem元素下增加一个子元素 *)
function AppendChildElement(const TagName, Value: WideString;
ParenElem: IDOMElement): IDOMElement;

(* 根据TagName取得XML节点下的某一个子节点 *)
function GetSingleEleByTagName(AEle: IDOMElement; TagName: WideString): IDOMElement;

(* 取得XML节点的文本 *)
function GetElementText(AElement: IDOMNode): WideString;

(* IDOMElement的text值转换成各种类型的数据，
       如果AElem=nil或者text不符合某些数据类型，返回Default值 *)
    function EleTextToBoolDef(AElem: IDOMElement; const Default: Boolean): Boolean;
    function EleTextToStrDef(AElem: IDOMElement; const Default: WideString): WideString;
    function EleTextToIntDef(AElem: IDOMElement; const Default: Integer): Integer;
    function EleTextToFloatDef(AElem: IDOMElement; const Default: Extended): Extended;

(* 取得IDomElement的属性的值，并转换成各种类型
       如果不符合数据类型，返回Default值 *)
    function EleAttrToBoolDef(AElem: IDOMElement; AttrName: WideString;
      const Default: Boolean): Boolean;
    function EleAttrToStrDef(AElem: IDOMElement;  AttrName: WideString;
      const Default: WideString): WideString;
    function EleAttrToIntDef(AElem: IDOMElement;  AttrName: WideString;
      const Default: Integer): Integer;
    function EleAttrToFloatDef(AElem: IDOMElement;  AttrName: WideString;
      const Default: Extended): Extended;

procedure ObjPropertyToElements(Obj: TObject); virtual;
    procedure ElementsToObjProperty(Obj: TObject); virtual;
  public
    procedure XMLToObjProperty(XMLStream: TStream; Obj: TObject);
    procedure ObjPropertyToXML(XMLStream: TStream; Obj: TObject);
    constructor Create;
    destructor Destroy; override;
  end;

implementation

{ TBaseConversion }

function TBaseConversion.AppendChildElement(const TagName,
  Value: WideString; ParenElem: IDOMElement): IDOMElement;
var
  Text: IDOMText;
begin
  Result := FXMLDoc.DOMDocument.createElement(TagName);
  if Value <> '' then
  begin
    Text := FXMLDoc.DOMDocument.createTextNode(Value);
    Result.appendChild(Text);
  end;
  ParenElem.appendChild(Result);
end;

constructor TBaseConversion.Create;
var
Vendor: TDOMVendor;
begin
FXMLDoc := TXMLDocument.Create(nil);

//下面这几句代码可以去掉，则将使用MSXML来解析
  //现在是用OpenXML的原生代码解析
  Vendor := DOMVendors.Find('Open XML');
  if Vendor <> nil then
    FXMLDoc.DOMVendor := Vendor;
end;

destructor TBaseConversion.Destroy;
begin
FXMLDoc.Free;
inherited;
end;

function TBaseConversion.EleAttrToBoolDef(AElem: IDOMElement; AttrName: WideString;
  const Default: Boolean): Boolean;
var
  LNode: IDOMNode;
begin
  Result := Default;
  if AElem <> nil then
  begin
    LNode := AElem.attributes.getNamedItem(AttrName);
    if LNode <> nil then
      Result := StrToBoolDef(LNode.nodeValue, Default);
  end
end;

function TBaseConversion.EleAttrToFloatDef(AElem: IDOMElement; AttrName: WideString;
  const Default: Extended): Extended;
var
  LNode: IDOMNode;
begin
  Result := Default;
  if AElem <> nil then
  begin
    LNode := AElem.attributes.getNamedItem(AttrName);
    if LNode <> nil then
      Result := StrToFloatDef(LNode.nodeValue, Default);
  end
end;

function TBaseConversion.EleAttrToIntDef(AElem: IDOMElement; AttrName: WideString;
  const Default: Integer): Integer;
var
  LNode: IDOMNode;
begin
  Result := Default;
  if AElem <> nil then
  begin
    LNode := AElem.attributes.getNamedItem(AttrName);
    if LNode <> nil then
      Result := StrToIntDef(LNode.nodeValue, Default);
  end
end;

function TBaseConversion.EleAttrToStrDef(AElem: IDOMElement; AttrName: WideString;
  const Default: WideString): WideString;
var
  LNode: IDOMNode;
begin
  Result := Default;
  if AElem <> nil then
  begin
    LNode := AElem.attributes.getNamedItem(AttrName);
    if LNode <> nil then
      Result := LNode.nodeValue;
  end
end;

procedure TBaseConversion.ElementsToObjProperty(Obj: TObject);
begin
end;

function TBaseConversion.EleTextToBoolDef(AElem: IDOMElement;
  const Default: Boolean): Boolean;
begin
  if AElem <> nil then
    Result := StrToBoolDef(GetElementText(AElem), Default)
  else
    Result := Default;
end;

function TBaseConversion.EleTextToFloatDef(AElem: IDOMElement;
  const Default: Extended): Extended;
begin
  if AElem <> nil then
    Result := StrToFloatDef(GetElementText(AElem), Default)
  else
    Result := Default;
end;

function TBaseConversion.EleTextToIntDef(AElem: IDOMElement;
  const Default: Integer): Integer;
begin
  if AElem <> nil then
    Result := StrToIntDef(GetElementText(AElem), Default)
  else
    Result := Default;
end;

function TBaseConversion.EleTextToStrDef(AElem: IDOMElement;
  const Default: WideString): WideString;
begin
  if AElem <> nil then
    Result := GetElementText(AElem)
  else
    Result := Default;
end;

function TBaseConversion.GetElementText(AElement: IDOMNode): WideString;
begin
Result := AElement.firstChild.nodeValue;
end;

function TBaseConversion.GetSingleEleByTagName(AEle: IDOMElement;
  TagName: WideString): IDOMElement;
var
  LNodeList: IDOMNodeList;
begin
  Result := nil;
  LNodeList := AEle.getElementsByTagName(TagName);
  if LNodeList <> nil then
    Result := LNodeList.item[0] as IDOMElement;
end;

procedure TBaseConversion.ObjPropertyToElements(Obj: TObject);
begin
end;

procedure TBaseConversion.ObjPropertyToXML(XMLStream: TStream;
  Obj: TObject);
begin
  FXMLDoc.XML.Clear;
  FXMLDoc.Active := True;
  FXMLDoc.Encoding := 'utf-8';
  ObjPropertyToElements(Obj);
  FXMLDoc.SaveToStream(XMLStream);
end;

procedure TBaseConversion.XMLToObjProperty(XMLStream: TStream;
  Obj: TObject);
begin
  FXMLDoc.LoadFromStream(XMLStream);
  ElementsToObjProperty(Obj);
end;

end.

http://blog.csdn.net/linzhengqun/article/details/529307

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