将Delphi作为ASP.NET的脚本语言

2024-07-10 13:12:02

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   将delphi视为脚本语言

   支持asp.net的第一件事是让asp.net将delphi视为脚本语言，让asp.net能够为各种asp文件类型调用delphi的.net编译器。

   asp.net要在iis虚路径的根目录下寻找web.config文件。下面是asp.net中使用delphi作脚本语言的web.config配制文件内容：

   <configuration>
   <system.web>
   <compilation debug="true">
   <assemblies>
   <add assembly="delphiprovider" />
   </assemblies>
   <compilers>
   <compiler language="delphi" extension=".pas"
   type="borland.delphi.delphicodeprovider,delphiprovider" />
   </compilers>
   </compilation>
   </system.web>
   </configuration>

   关于web配制文件的详情请参msdn：
   http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpguide/html/cpconformatofconfigurationfiles.asp

   在我的机器(win2k pro)上测试delphi对asp.net的支持。要增加一个虚路径来安放delphi脚本，我把这个路径名定为"vslive"。

   在我的机器配制文件上作了这个小改动后就可以来看asp.net是如何将delphi视为脚本语言的。

   在asp.net中使用delphi代码
   首先编写一个简单应用来确认我们的delphi支持配制是正确的。下面是editdemo.aspx文件的代码，有一个文本输入框，一个按钮。按钮事件触发显示输入框内容。

   <html>
   <script language="delphi" runat="server">
   procedure buttonclick(sender: system.object; e: eventargs);
   begin
   message.text := edit1.text;
   end;
   </script>
   <body>
   <form runat="server">
   <asp:textbox id="edit1" runat="server"/>
   <asp:button text="click me!" onclick="buttonclick" runat="server"/>
   </form>
   <p><b><asp:label id="message" runat="server"/></b></p>
   </body>
   </html>

   可以看到，asp按钮对象的onclick事件触发delphi的buttonclick过程，而delphi程序里却使用了asp对象label message和text box edit1。虽然在delphi过程中没有定义asp的二个变量，delphi代码却能找到它们。这是因为脚本中含有的delphi服务模块能够产生相应的delphi代码。

   现在可以用本地浏览器来浏览这个网页了。因为我把脚本放在"vslive"虚路径，所以打开：
   http://localhost/vslive/editdemo.aspx.

   以下是编译之后形成的delphi代码，代码产生webform：

//------------------------------------------------------------------------------
  // <autogenerated>
  // 本代码由一个工具生成
  // 运行版本：1.0.3705.209
  //
  // 修改本文件将导致异常行为并丢失生成的代码。
  // </autogenerated>
  //------------------------------------------------------------------------------

  unit asp;

  interface

  uses system.collections, system.collections.specialized, system.configuration,
   system.text, system.text.regularexpressions, system.web, system.web.caching,
   system.web.sessionstate, system.web.security, system.web.ui, system.web.ui.webcontrols,
   system.web.ui.htmlcontrols, system.globalization;

  var
   editdemo_aspx___autohandlers: integer;
   editdemo_aspx___intialized: boolean = false;
   editdemo_aspx___filedependencies: system.collections.arraylist;
  type
   editdemo_aspx = class(system.web.ui.page, system.web.sessionstate.irequiressessionstate)
   protected
   edit1: system.web.ui.webcontrols.textbox;
   __control3: system.web.ui.webcontrols.button;
   __control2: system.web.ui.htmlcontrols.htmlform;
   message: system.web.ui.webcontrols.label;
   procedure buttonclick(sender: system.object; e: eventargs);
   public
   constructor create;
   function get_autohandlers: integer; override;
   function get_applicationinstance: system.web.httpapplication; virtual;
   function get_templatesourcedirectory: system.string; override;
   procedure set_autohandlers(value: integer); override;
   protected
   property autohandlers: integer read get_autohandlers write set_autohandlers;
   property applicationinstance: system.web.httpapplication read get_applicationinstance;
   public
   property templatesourcedirectory: system.string read get_templatesourcedirectory;
   private
   function __buildcontroledit1: system.web.ui.control;
   function __buildcontrol__control3: system.web.ui.control;
   function __buildcontrol__control2: system.web.ui.control;
   function __buildcontrolmessage: system.web.ui.control;
   procedure __buildcontroltree(__ctrl: system.web.ui.control);
   protected
   procedure frameworkinitialize; override;
   public
   function gettypehashcode: integer; override;
   end;

  implementation


   procedure editdemo_aspx.buttonclick(sender: system.object; e: eventargs);
   begin
   message.text := edit1.text;
   end;
   constructor editdemo_aspx.create;
  var
   dependencies: system.collections.arraylist;
  begin
   inherited create;

   if (asp.editdemo_aspx___intialized = false) then
   begin
   dependencies := system.collections.arraylist.create;
   dependencies.add('d:/vslive/editdemo.aspx');
   asp.editdemo_aspx___filedependencies := dependencies;
   asp.editdemo_aspx___intialized := true;
   end;
   self.server.scripttimeout := 30000000;
  end;

  function editdemo_aspx.get_autohandlers: integer;
  begin
   result := asp.editdemo_aspx___autohandlers;
  end;

  function editdemo_aspx.get_applicationinstance: system.web.httpapplication;
  begin
   result := self.context.applicationinstance as system.web.httpapplication;
  end;

  function editdemo_aspx.get_templatesourcedirectory: system.string;
  begin
   result := '/vslive';
  end;

  procedure editdemo_aspx.set_autohandlers(value: integer);
  begin
   asp.editdemo_aspx___autohandlers := value;
  end;

  function editdemo_aspx.__buildcontroledit1: system.web.ui.control;
  var
   __ctrl: system.web.ui.webcontrols.textbox;
  begin

   __ctrl := system.web.ui.webcontrols.textbox.create;
   self.edit1 := __ctrl;
   __ctrl.id := 'edit1';
   __ctrl.width := system.web.ui.webcontrols.unit.parse('300px', system.globalization.cultureinfo.invariantculture);
   result := __ctrl;
  end;

  function editdemo_aspx.__buildcontrol__control3: system.web.ui.control;
  var
   __ctrl: system.web.ui.webcontrols.button;
  begin

   __ctrl := system.web.ui.webcontrols.button.create;
   self.__control3 := __ctrl;
   __ctrl.text := 'click me!';
   __ctrl.add_click(self.buttonclick);
   result := __ctrl;
  end;

  function editdemo_aspx.__buildcontrol__control2: system.web.ui.control;
  var
   __parser: system.web.ui.iparseraccessor;
   __ctrl: system.web.ui.htmlcontrols.htmlform;
  begin

   __ctrl := system.web.ui.htmlcontrols.htmlform.create;
   self.__control2 := __ctrl;
   __parser := __ctrl as system.web.ui.iparseraccessor;
   __parser.addparsedsubobject(system.web.ui.literalcontrol.create(''#13#10' '));
   self.__buildcontroledit1;
   __parser.addparsedsubobject(self.edit1);
   __parser.addparsedsubobject(system.web.ui.literalcontrol.create(''#13#10' '));
   self.__buildcontrol__control3;
   __parser.addparsedsubobject(self.__control3);
   __parser.addparsedsubobject(system.web.ui.literalcontrol.create(''#13#10' '));
   result := __ctrl;
  end;

  function editdemo_aspx.__buildcontrolmessage: system.web.ui.control;
  var
   __ctrl: system.web.ui.webcontrols.label;
  begin

   __ctrl := system.web.ui.webcontrols.label.create;
   self.message := __ctrl;
   __ctrl.id := 'message';
   result := __ctrl;
  end;

  procedure editdemo_aspx.__buildcontroltree(__ctrl: system.web.ui.control);
  var
   __parser: system.web.ui.iparseraccessor;
  begin
   __parser := __ctrl as system.web.ui.iparseraccessor;
   __parser.addparsedsubobject(system.web.ui.literalcontrol.create('<html>'#13#10' '));
   __parser.addparsedsubobject(system.web.ui.literalcontrol.create(''#13#10' <body>'#13#10' '));
   self.__buildcontrol__control2;
   __parser.addparsedsubobject(self.__control2);
   __parser.addparsedsubobject(system.web.ui.literalcontrol.create(''#13#10' <p><b>'));
   self.__buildcontrolmessage;
   __parser.addparsedsubobject(self.message);
   __parser.addparsedsubobject(system.web.ui.literalcontrol.create('</b></p>'#13#10' </body>'#13#10'</html>'#13#10));
  end;

  procedure editdemo_aspx.frameworkinitialize;
  begin
   self.__buildcontroltree(self);
   self.filedependencies := asp.editdemo_aspx___filedependencies;
   self.enableviewstatemac := true;
  end;

  function editdemo_aspx.gettypehashcode: integer;
  begin
   result := -764444463;
  end;

  end.

  注意：这里介绍的是delphi的.net编译器功能的预览。正式发布的delphi 7生成的代码与上面将有显著不同。本文仅是示例说明如何在asp.net中使用delphi及其功能。

   更高技术的网页
  asp.net的一些控件远比html控件要更加智能化。其中之一就是日历(calendar)控件。

  以下代码是calendar.aspx中的一部分。代码提供二种方法让控件设置日期：
  　浏览日历然后选择日期；
  　按照日期格式输入日期，确认选择。这种方法由.net的convert类支持。

  <script language="delphi" runat="server">
  procedure calendar1selected(sender: system.object; e: eventargs);
  begin
   label1.text := 'delphi for .net says you picked ' + calendar1.selecteddate.tostring('d');
  end;

  procedure button1click(sender: system.object; e:eventargs);
  begin
   calendar1.visibledate := system.convert.todatetime(edit1.text);
   label1.text := 'delphi for .net says you set ' + calendar1.visibledate.tostring('d');
  end;
  </script>

  <body >
   <form runat="server">
   <center>
   <h1>delphi for .net running in asp.net</h1>
   <p>please pick a date</p>
   <asp:calendar id="calendar1" runat="server" forecolor="#0000ff" backcolor="#ffffcc"
   onselectionchanged="calendar1selected">
   <todaydaystyle font-bold="true"/>
   <nextprevstyle forecolor="#ffffcc"/>
   <dayheaderstyle backcolor="#ffcc66"/>
   <selecteddaystyle forecolor="black" backcolor="#ccccff"/>
   <titlestyle font-size="14pt" font-bold="true" forecolor="#ffffcc" backcolor="#990000"/>
   <othermonthdaystyle forecolor="#cc9966"/>
   </asp:calendar>
   <p><asp:textbox id="edit1" width=200 runat="server"/>
   <asp:button text="set date" id="button1" onclick="button1click" runat="server" />
   </p>
   <p><asp:label id="label1" runat="server"/></p>
   </center>
   </form>
  </body>

  在日历上选择日期触发onselectionchanged事件，调用delphi的calendar1selected()过程。
  输入日期，点击"set data"按钮触发button1click事件，调用delphi的button1click()过程。

  数据处理
  现在通过日历的日期选择来选择显示数据库数据。在这个asp.net delphi网页上，增加一个datagrid和一个textbox，前者显示数据库数据，后者输入要显示的数据库域。

  <%@import namespace="system.data"%>
  <%@import namespace="system.data.sqlclient"%>

  <script language="delphi" runat="server">
  const
   prodname = 'delphi for .net';
   dispfields = 'orderid, customerid, shipname, shipcity, shipcountry';

  procedure dateselected(sender: system.object; e: eventargs);
  begin
   label1.text := prodname + ' says you picked ' + calendar1.selecteddate.tostring('d');
   datagrid1.datasource := getorders(calendar1.selecteddate);
   datagrid1.databind;
  end;

  procedure button1click(sender: system.object; e:eventargs);
  begin
   calendar1.visibledate := system.convert.todatetime(edit1.text);
   label1.text := prodname + ' says you set ' + calendar1.visibledate.tostring('d');
  end;

  procedure button2click(sender: system.object; e:eventargs);
  begin
   displayfields.text := dispfields;
  end;

  function getorders(date : datetime) : dataset;
  var
   adapter : sqldataadapter;
  begin
   adapter := sqldataadapter.create(
   'select ' + displayfields.text + ' from orders '+
   'where orderdate = ''' + date.tostring('d')+'''',
   'server=(local);database=northwind;trusted_connection=yes');
   result := dataset.create;
   adapter.fill(result);
  end;

  </script>

  <body >
   <form runat="server">
   <h1><%=prodname %> with a calendar, datagrid, & sqlclient in asp.net</h1>
   <table>
   <tr valign="top"><td>
   <p><b>pick a date</b></p>
   <asp:calendar id="calendar1" runat="server" forecolor="#0000ff" backcolor="#ffffcc"
   onselectionchanged="dateselected">
   <todaydaystyle font-bold="true"/>
   <nextprevstyle forecolor="#ffffcc"/>
   <dayheaderstyle backcolor="#ffcc66"/>
   <selecteddaystyle forecolor="black" backcolor="#ccccff"/>
   <titlestyle font-size="14pt" font-bold="true" forecolor="#ffffcc" backcolor="#990000"/>
   <othermonthdaystyle forecolor="#cc9966"/>
   </asp:calendar>
   <p><asp:textbox id="edit1" width=150 runat="server"/>
   <asp:button text="set date" id="button1" onclick="button1click" runat="server" />
   </p>
   </td><td valign="top">
   <p><b>display fields:</b> <asp:textbox id="displayfields"
   text="orderid, customerid, shipname, shipcity, shipcountry" width=500 runat="server"/>
   <asp:button text="reset fields" id="button2" onclick="button2click" runat="server" /></p>
   <asp:datagrid id="datagrid1" runat="server" bordercolor="#ffcc66" forecolor="#0000ff">
   <headerstyle forecolor="#ffffcc" backcolor="#990000"/>
   </asp:datagrid>
   </td></tr></table>
   <p><asp:label id="label1" runat="server"/></p>
   </form>
  </body>

  每当用户点击日历选择日期时，就触发onselectionchanged事件，调用dateselected()函数。
  在getorders函数中，数据库的连接由命名空间定义的sqlclient实现，数据库是ms sql 2000的示范库northwind。sqldataadapter将查询结果安装到datagrid中，显示出数据表格，如附图。

  改变域输入框的域名，再点击日历，就得到不同的结果。

  这就是日历驱动的数据库查询系统，由delphi for .net与asp.net共同完成。

  结语
  本文试图简略说明在asp.net中应用delphi是如何方便。
  请记住，本文示例是delphi 7的预览示例，正式版本的结果也许不完全如此，当然也许就是如此。