如何构建积木式Web应用
上下文
问题
环境
预备知识
最好具备以下知识
解决方案
public class MyPlaceHolder : PlaceHolder
{
private string userControl; // 要载入的UserControl目录下的.ascx
private string pageControl; // 要载入的Page目录下的.ascx
public MyPlaceHolder()
{
userControl = "";
pageControl = "";
}
public string UserControl
{
get
{
return userControl;
}
set
{
userControl = value;
}
}
public string PageControl
{
get
{
return pageControl;
}
set
{
pageControl = value;
}
}
// 当需要载入多个UserControl时，可以直接调用LoadUserControl
// 当只需要载入一个UserControl时，可以调用Clear清除载入过的内容
public void Clear()
{
this.Controls.Clear();
}
// 载入UserControl目录下的.ascx
// 以及导入对应的css文件
public void LoadUserControl(string UserControl)
{
this.userControl = UserControl;
BasePage page = (BasePage)this.Page;
// 请参考后面的BasePage的代码
Control control = this.Page.LoadControl(
page.Scheme + "usercontrol/" + userControl + ".ascx");
string css = "css/" + userControl + ".css";
// 对应的css文件
if(File.Exists(this.Page.MapPath(page.Scheme+css)))
{
page.AddCss(page.Scheme + css);
}
this.Controls.Add(control);
}
// 载入Page目录下的.ascx
// LoadPage与LoadUserControl的区别是两者载入的.ascx所在的目录不同
// Page目录下的.ascx可以看成是一些搭建主体结构的.ascx,其使用MyPlaceHolder
// 来包含最基础的积木块.ascx(在UserControl目录下)
public void LoadPage(string PageControl)
{
this.PageControl = PageControl;
BasePage page = (BasePage)this.Page;
Control control = this.Page.LoadControl(
page.Scheme + "page/" + pageControl + ".ascx");
string css = "css/" + pageControl + ".css";
if(File.Exists(this.Page.MapPath(page.Scheme+css)))
{
page.AddCss(page.Scheme + css);
}
this.Controls.Add(control);
}
protected override void OnLoad(EventArgs e)
{
base.OnLoad(e);
if(!userControl.Equals(string.Empty))
{
LoadUserControl(userControl);
}
}
}
public class MyPlaceHolder : PlaceHolder
{
private string userControl; // 要载入的UserControl目录下的.ascx
private string pageControl; // 要载入的Page目录下的.ascx
public MyPlaceHolder()
{
userControl = "";
pageControl = "";
}
public string UserControl
{
get
{
return userControl;
}
set
{
userControl = value;
}
}
public string PageControl
{
get
{
return pageControl;
}
set
{
pageControl = value;
}
}
// 当需要载入多个UserControl时，可以直接调用LoadUserControl
// 当只需要载入一个UserControl时，可以调用Clear清除载入过的内容
public void Clear()
{
this.Controls.Clear();
}
// 载入UserControl目录下的.ascx
// 以及导入对应的css文件
public void LoadUserControl(string UserControl)
{
this.userControl = UserControl;
BasePage page = (BasePage)this.Page;
// 请参考后面的BasePage的代码
Control control = this.Page.LoadControl(
page.Scheme + "usercontrol/" + userControl + ".ascx");
string css = "css/" + userControl + ".css";
// 对应的css文件
if(File.Exists(this.Page.MapPath(page.Scheme+css)))
{
page.AddCss(page.Scheme + css);
}
this.Controls.Add(control);
}
// 载入Page目录下的.ascx
// LoadPage与LoadUserControl的区别是两者载入的.ascx所在的目录不同
// Page目录下的.ascx可以看成是一些搭建主体结构的.ascx,其使用MyPlaceHolder
// 来包含最基础的积木块.ascx(在UserControl目录下)
public void LoadPage(string PageControl)
{
this.PageControl = PageControl;
BasePage page = (BasePage)this.Page;
Control control = this.Page.LoadControl(
page.Scheme + "page/" + pageControl + ".ascx");
string css = "css/" + pageControl + ".css";
if(File.Exists(this.Page.MapPath(page.Scheme+css)))
{
page.AddCss(page.Scheme + css);
}
this.Controls.Add(control);
}
protected override void OnLoad(EventArgs e)
{
base.OnLoad(e);
if(!userControl.Equals(string.Empty))
{
LoadUserControl(userControl);
}
}
}
使用方法： <HomeOffice:MyPlaceHolder id="Myplaceholder1" runat="server" UserControl="Header"> </HomeOffice:MyPlaceHolder> // 这里的Header是位于UserControl目录下的Header.ascx
<%@ Register TagPrefix="HomeOffice"
Namespace="HomeOffice.Web.UI.WebControl"
Assembly = "HomeOffice.Web.UI" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" >
<HTML>
<HEAD>
<title>构建积木式应用程序</title>
<asp:Literal ID="CssHolder" runat="server"></asp:Literal>
<asp:Literal ID="ScriptHolder" Runat="server"></asp:Literal>
<style>
BODY { margin-left : 0px; margin-right : 0px; }
</style>
</HEAD>
<body bgcolor="#e6e6e6">
<form id="Form1" method="post" runat="server"
enctype="multipart/form-data">
<table width="100%" cellpadding="0" cellspacing="0">
<tr>
<td> </td>
<td width="800">
<table width="100%" cellpadding="0" cellspacing="0">
<tr>
<td>
<HomeOffice:MyPlaceHolder id="PlaceHolder1"
runat="server" UserControl="Header">
</HomeOffice:MyPlaceHolder>
</td>
</tr>
<tr>
<td>
<HomeOffice:MyPlaceHolder id="Myplaceholder1"
runat="server" UserControl="MainMenu">
</HomeOffice:MyPlaceHolder>
</td>
</tr>
<tr>
<td style="height:6px;background:#f6f6f6;font-size:1px;
border-top:1px solid white;">
</td>
</tr>
<tr>
<td style="height:4px;background:#e1e1e1;font-size:1px;
border-top:1px solid #e6e6e6; ">
</td>
</tr>
<tr>
<td style="background:white;border-bottom:1px solid #bbbbbb">
<HomeOffice:MyPlaceHolder id="PageBody" runat="server">
</HomeOffice:MyPlaceHolder>
</td>
</tr>
<tr>
<td style="padding-top:20px">
<HomeOffice:MyPlaceHolder id="Myplaceholder2"
runat="server" UserControl="Footer">
</HomeOffice:MyPlaceHolder>
</td>
</tr>
</table>
</td>
<td> </td>
</tr>
</table>
</form>
</body>
</HTML>
public class BasePage : Page
{
public string Scheme = "/Scheme/blue/"; // 所采用的主题
public AppSetting Setting;
// 环境配置，在Init中分析，其内容包括解析http请求到正确的Page目录下的
// 文件，建立当前登陆用户的信息
public Control focusControl; // 当页面载入后，首先获得焦点的控件
private Literal CssHolder; // 要导入的css
private Literal ScriptHolder; // 要导入的script文件
public BasePage()
{
focusControl = null;
}
// 导入css文件引用
public void AddScript(string script)
{
// 进行IsPostBack判断的原因是
// 防止重复导入
if(!this.IsPostBack)
{
ScriptHolder.Text += string.Format("<script src=\"{0}\"
type=\"text/javascript\"></script>\n", script);
}
}
// 导入script文件引用
public void AddCss(string css)
{
if(!this.IsPostBack)
{
CssHolder.Text += "<link rel=\"stylesheet\"
type=\"text/css\" href=\"" + css + "\">\n";
}
}
// 载入http请求分析后的Page目录下的所请求的文件
public void LoadPageTemplate()
{
Control control = (Control)this.LoadControl
(this.Scheme+"PageTemplate.ascx");
CssHolder = (Literal)control.FindControl("CssHolder");
ScriptHolder = (Literal)control.FindControl("ScriptHolder");
this.Controls.Add(control);
MyPlaceHolder body = (MyPlaceHolder)
control.FindControl("PageBody");
body.LoadPage(this.Setting.TargetPage);
// 调用MyPlaceHolder的LoadPage方法
// TargetPage记录了请求的页面
}
protected override void OnInit(EventArgs e)
{
base.OnInit(e);
// 分析http请求
Setting = new AppSetting(this.Request.Path);
// 设置用户信息
if(this.Request.IsAuthenticated)
{
Setting.SetUser(User.Identity.Name);
}
}
protected override void OnLoad(EventArgs e)
{
base.OnLoad(e);
this.LoadPageTemplate();
}
// 当页面显示后，初始获得焦点的控件
protected void SetFocusControl()
{
if(this.focusControl==null) return;
string template = @"<script language='jscript'>
document.all.{0}.focus();</script>";
string script = string.Format(template,
this.focusControl.ClientID);
this.RegisterStartupScript("FocusControl", script);
}
protected override void OnPreRender(EventArgs e)
{
base.OnPreRender(e);
SetFocusControl();
}
// 修复了asp.net 1.1的一个bug
// 没有这段代码，LinkButton等某些服务器将无法使用
protected override void Render(HtmlTextWriter writer)
{
StringBuilder stringBuilder = new StringBuilder();
StringWriter stringWriter = new StringWriter(stringBuilder);
HtmlTextWriter htmlWriter = new HtmlTextWriter(stringWriter);
base.Render(htmlWriter);
string html = stringBuilder.ToString();
int start = html.IndexOf("<form name=\"") + 12;
int end = html.IndexOf("\"", start);
string formID = html.Substring(start, end - start);
string replace = formID.Replace(":", "_");
html = html.Replace("document."+formID,"document."+replace);
writer.Write(html);
}
}
在web.config中进行如下配置，让httphandler生效： <httpHandlers> <add verb="*" path="*.aspx" type="HomeOffice.Web.UI.HttpHandler.MyPageHandlerFactory, HomeOffice.Web.UI"/> </httpHandlers>
public class MyPageHandlerFactory : IHttpHandlerFactory
{
public virtual IHttpHandler GetHandler(HttpContext context,
String requestType,
String url,
String pathTranslated)
{
return new BasePage();
}
public virtual void ReleaseHandler(IHttpHandler handler)
{
}
}
public class AppSetting
{
public string Url; // request url
public string Site; // request site
public string User; // login name
public string UserName; // display name
public string TargetPage; // target page
public string[] Roles; // user roles in the site
private Hashtable parameter = new Hashtable();
public AppSetting()
{
Site = "default";
User = "*";
UserName = "";
Roles = null;
}
public AppSetting(string url) : this()
{
this.Url = url.ToLower();
AnalysisUrl(this.Url);
}
public object this[string key]
{
get { return parameter[key]; }
set { parameter.Add(key, value); }
}
// 分析用户所请求的页面和参数
protected void AnalysisPage(string url)
{
PageInfo[] pages = XmlHomeOffice.Pages();
foreach(PageInfo page in pages)
{
if(Regex.IsMatch(url,page.pattern,RegexOptions.IgnoreCase))
{
this.TargetPage = string.Format(page.target_page,
url.Replace(".aspx","").Split('/'));
if(!page.parameter.Equals(string.Empty))
{
string p = string.Format(page.parameter,
url.Replace(".aspx", "").Split('/'));
string[] ps = p.Split(',');
foreach(string str in ps)
{
string[] item = str.Split('=');
this[item[0]] = item[1];
}
}
return;
}
}
// No one matched, a Exception occur
this.TargetPage = "error";
}
// 分析出站点，类似于blog中的每个站点
protected string AnalysisSite(string url)
{
if(url[0]=='/')
{
url = url.Remove(0, 1);
}
string[] items = url.Split('/');
if(items.Length<1)
{
return Site + "/default.aspx";
}
if(items[0].EndsWith(".aspx"))
{
return Site + "/" + url;
}
string[] reserved_words = XmlHomeOffice.ReservedWords();
foreach(string str in reserved_words)
{
if(items[0].Equals(str.ToLower()))
{
return Site + "/" + url;
}
}
Site = items[0];
return url;
}
public void AnalysisUrl(string url)
{
Url = AnalysisSite(url);
AnalysisPage(Url);
}
public void SetUser(string user)
{
User = user;
UserName = XmlUsers.GetDisplayName(user);
XmlSiteProfile profile = new XmlSiteProfile(Site);
Roles = profile.SiteUserRole(user);
}
public bool HasRole(string role)
{
if(Roles==null) return false;
foreach(string str in Roles)
{
if(str.Equals(role)) return true;
}
return false;
}
}
<pages>
<page pattern="^(\/testboth.aspx)$"
parameter="" target-page="testboth" />
<page pattern="^(\/\w+.aspx)$"
parameter="" target-page="{1}" />
</pages>
<%@ Control Language="c#" AutoEventWireup="false" Inherits="HomeOffice.UserControl.PageTemplate" %>
流程说明
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建立如下的数据库，表，存储过程： 数据库：test 访问账号：sa，sa（可以在web.config中修改） 表：test 字段 test_id（自增），string（nvarchar（50）），number（int） 存储过程： testaddnew：（没有参数） insert into test(string, number) values(‘’, 0); testget： （没有参数） select * from test testdelete：（输入参数：@test_id int） delete from test where test_id = @teat_id testupate：（参数：@test_id, @string, @number） update test set string=@string, number=@number where test_id=@test_id
http://localhost/testtextbox.aspx
http://localhost/testdatagrid.aspx
http://www.smartyouth.net/scheme.rar
相关知识
http://www.microsoft.com/china/msdn/architecture/patterns/Esp/
http://scottwater.com/DotText/default.aspx