Delphi6

delphi6的新特性

delphi6的新特性
BizSnap™ simplifies eBusiness integration by easily and seamlessly creating and using XML/SOAP based Web Services
Delphi 6 radically simplifies building next-generation eBusiness applications on the Internet with complete SOAP based Web Services and XML data exchange support. The seamless integration of XML and Web Services technologies with Delphi 6 delivers the only Rapid Application Development for industry standard Web Services and B2B, B2C, and P2P integration over the Internet.

WebSnap™ is a component-based Web application development framework that supports leading Web Application Servers, including Apache, Netscape and Microsoft Internet Information Services (IIS)
WebSnap integrates the power of Delphi directly into today's Web site development teams. With WebSnap, Delphi applications can seamless integrate with Web sites and Web site development teams using today's popular HTML development environments such as Dreamweaver, Frontpage, VBScript, and JavaScript.

DataSnap™ delivers high-performance, Web Service-enabled database middleware that enables any client application or service to easily connect with any major database over the Internet
DataSnap supports all major database servers such as Oracle, MS-SQL Server, Informix, IBM DB2, Sybase and interbase. Client applications connect to high-performance DataSnap servers through industry standard SOAP/XML HTTP connections over the Internet without bulky database client drivers and complex configuration requirements. DCOM, CORBA, and TCP/IP connections are also supported.

Build Single Source Windows/Linux Applications
Delphi 6 is Kylix compatible! Use the Cross-platform CLX™ component library and visual designers to build high-performance portable applications for Windows that can be easily re-compiled on Linux with Borland Kylix (sold separately). Plus! Bring CLX based Linux applications from Kylix into Delphi 6 to easily re-compile on Windows. Delphi 6 includes BaseCLX, VisualCLX, DataCLX, and NetCLX components.

Delphi 6 Borland AppServer Integration
Connect any Delphi 6 application or Web Service with Borland AppServer/EJBs using new SIDL (Simple IDL). Easily build ultra high-performance rich GUI Windows clients for EJB based AppServer applications. Publish AppServer EJB functionality to the world over Internet as industry standard SOAP/XML Web services.

Borland visibroker for Delphi - Client and Server Development
Build ultra-high performance rich GUI Windows and Web Browser clients for Visibroker CORBA and AppServer/EJB applications. And now in Delphi 6 build CORBA Visibroker server objects that are interoperable with any CORBA client or object in a heterogeneous IT environment.

Latest Windows 2000/ME and Office 2000 GUI Support
Build the most modern user interfaces with new ActionBands, ActionManagers, and Shell Controls to easily create dynamic user interfaces that follow the latest Microsoft UI trends. Take all the work out of complex user interfaces while letting end-users fully customize their own UI experience.

Delphi6XML數據綁定

Delphi 6 含有許多更新更強的XML支持功能，增加了XML檔案編程，XML數據綁定嚮導，XML映象和BizSnap(SOAP/XML Web服務)。我在上一篇文章論述了Delphi 6中的XML檔案編程(XML Document Programming)。本文是三篇論述Delphi 6中XML功能系列文章的第二篇，論述Delphi 6中的XML數據綁定(XML Data Binding)。

XML檔案編程
XMLDocument組件讓我們能夠遍歷和編輯XML檔案。但是在上一篇文章中我提到了，我們只能與無類型節點打交道，必須記住節點元素的名字。這意味著無法進行實時編譯調試！幸虧的是，如果Delphi只能處理這樣簡單的問題就不成其為Delphi了。運用XML的內容相關結構可以做更高級的套用，這就是Delphi 6的XML數據綁定嚮導(XML Data Binding Wizard)。

XML數據綁定
在Delphi 6的模組倉庫(Object Repository)中可以找到XML數據綁定嚮導(XML Data Binding Wizard)。程式設計師能夠用它生成相應的接口和類來訪問與修改XML檔案數據，諸如ClientDataSetXML數據，ADO XML數據，其它XML檔案數據(如我們在前文用到的Clinic.xml，本文繼續使用這個簡單的XML檔案作示例)。

現在開始吧，啟動Delphi 6，在主選單上選擇File | New - Other，然後在倉庫中選擇XML Data Binding，如圖1所示。

嚮導有三個頁面。第一頁定義XML綱(Schema)或XML檔案(本例用Clinic.xml)，如圖2所示。
在資源輸入框內輸入XML綱(Schema)或XML檔案。“選項”(Options)對話框定義編碼選項和數據類型映射關係(Data Type map)。以後我們還會談到這些選項。

嚮導的第二頁顯示了樹結構和節點數據類型(亦即嚮導生成了些什麼樣的代碼)。圖3可以看到我的XML檔案結構。
可以看到XML檔案里描述的嵌套節點(ClinicsType與ClinicType)和單節點(String)。這時可以打開選項(Options)對話框(圖4)，修改編碼(比如修改前綴)和數據類型映射。

嚮導的第三頁顯示生成的相應接口和類。可以把這些結果保存到檔案(例如生成Clinic.xdb)。
結果(存儲為Clinic.xdb檔案)顯示如下。我們得到一個ClinicsType類型的Clinics元素，其中包括ClinicType類型的Clinic系列元素。

檔案同時定義ClinicType類型的Clinic元素包含一系列字元串元素(Title, Date和Topics)。

生成代碼
嚮導生成的代碼可以直接在套用中使用。不幸的是，Delphi 6有時會產生“非法操作”的出錯信息。重新執行一遍，它又能工作了。
以下是生成的代碼(Clinic.pas)：

{****************************************************}
{ }
{ Delphi XML Data Binding }
{ }
{ Generated on: 2001/11/07 00:37:00 }
{ Generated from: D:\D6Clinic\src\Clinic.xml }
{ Settings stored in: D:\D6Clinic\src\Clinic.xdb }
{ }
{****************************************************}
unit Clinic;
interface
uses xmldom, XMLDoc, XMLIntf;

type

{ Forward Decls }

IXMLClinicsType = interface;
IXMLClinicType = interface;

{ IXMLClinicsType }

IXMLClinicsType = interface(IXMLNodeCollection)
['{06723E03-662D-11D5-81CE-00104BF89DAD}']
{ Property Accessors }
function Get_Clinic(Index: Integer): IXMLClinicType;
{ Methods & Properties }
function Add: IXMLClinicType;
function Insert(const Index: Integer): IXMLClinicType;
property Clinic[Index: Integer]: IXMLClinicType
read Get_Clinic; default;
end;

{ IXMLClinicType }

IXMLClinicType = interface(IXMLNode)
['{06723E04-662D-11D5-81CE-00104BF89DAD}']
{ Property Accessors }
function Get_No: WideString;
function Get_Title: WideString;
function Get_Date: WideString;
function Get_Topics: WideString;
procedure Set_No(Value: WideString);
procedure Set_Title(Value: WideString);
procedure Set_Date(Value: WideString);
procedure Set_Topics(Value: WideString);
{ Methods & Properties }
property No: WideString read Get_No write Set_No;
property Title: WideString read Get_Title write Set_Title;
property Date: WideString read Get_Date write Set_Date;
property Topics: WideString read Get_Topics write Set_Topics;
end;

{ Forward Decls }

TXMLClinicsType = class;
TXMLClinicType = class;

{ TXMLClinicsType }

TXMLClinicsType = class(TXMLNodeCollection, IXMLClinicsType)
protected
{ IXMLClinicsType }
function Get_Clinic(Index: Integer): IXMLClinicType;
function Add: IXMLClinicType;
function Insert(const Index: Integer): IXMLClinicType;
public
procedure AfterConstruction; override;
end;

{ TXMLClinicType }

TXMLClinicType = class(TXMLNode, IXMLClinicType)
protected
{ IXMLClinicType }
function Get_No: WideString;
function Get_Title: WideString;
function Get_Date: WideString;
function Get_Topics: WideString;
procedure Set_No(Value: WideString);
procedure Set_Title(Value: WideString);
procedure Set_Date(Value: WideString);
procedure Set_Topics(Value: WideString);
end;

{ Global Functions }

function GetClinics(Doc: IXMLDocument): IXMLClinicsType;
function LoadClinics(const FileName: WideString): IXMLClinicsType;
function NewClinics: IXMLClinicsType;

這裡有二個接口類型：IXMLClinicsType和IXMLClinicType；用二個類(TXMLClinicsType和TXMLClinicType)來執行這二個接口。另外還有三個全局函式：GetClinics (獲得根元素)，LoadClinics (從外部XML檔案載入)和NewClinics (在記憶體生成新文件)。

用法
使用生成的Clinic.pas單元是很容易的。跟前一篇文章的做法一樣，使用XMLDocument組件(在Inernet標籤內)。不過我們不再使用無類型節點了，我們可以調用GetClinics函式獲得IXMLClinicsType類型。以下是具體操作過程：

在Delphi 6建立一個新的套用(project)
在XML數據綁定嚮導指引下建立Clinic.pas檔案(經過命名存檔 - 譯者)
在主窗體上加入一個XMLDocument組件，其FileName屬性為Clinic.xml
在主窗體的OnCreate事件中加入以下代碼：
procedure TForm1.FormCreate(Sender: TObject);
var
Clinics: IXMLClinicsType;
begin
Clinics := GetClinics(XMLDocument1);
end;

把Clinics變數放到主窗體中是很有用的，這樣就可以在主窗體運行期間使用Clinics接口。使用IXMLClinicsType變數類型要比以前使用普通XMLDocument組件方便多了。現在可以通過Get_Clinic方法來獲得各個Clinic元素，還可以在特定位置插入新的Clinic元素。用Clinics.Clinic可以獲得節點元素，用Getter和Setter方法可以得到或設定元素值。現在可以直接訪問No, Title, Date, Topics等屬性了：
procedure TForm1.ButtonGetClick(Sender: TObject);
var
Clinic: IXMLClinicType;
begin
Clinic := Clinics.Clinic[0];
EditNo.Text := Clinic.No;
EditTitle.Text := Clinic.Title;
EditDate.Text := Clinic.Date;
EditTopics.Text := Clinic.Topics
end;

可以在Clinic.pas中看到，Getter和Setter是方法而不是屬性(實際上，我始終認為使用屬性更清楚些)。但是Delphi 6讓你看到的卻是屬性描述而不是方法本身(Delphi 6的另一個受歡迎的優點)。將上面這段代碼與前一篇文章使用的方法相比較，就能感到操作方便多了。

下面的例子在XML樹的末尾加入一個節點：
procedure TForm1.ButtonAddClick(Sender: TObject);
begin
with Clinics.Add do
begin
No := '2001-2-8; // 8th Clinic of the 2nd series of 2001
Title := 'Special Kylix 2 Clinic';
Date := '2001/12/21';
Topics := 'Kylix 2 New Features'
end
end;

如果沒有把XMLDocument組件的AutoSave設定為真，可以用以下方法保存更動結果：
procedure TForm1.FormDestroy(Sender: TObject);
begin
XMLDocument1.SaveToFile;
end;

這就是XML數據綁定嚮導，一個非常方便的方法。它能做得越來越好。