Programming.ASP.Dot.NET.2nd.Edition 学习笔记

June 8,
1, Use code behind
1) Use VS.NET IDE <%@ Page inherits=="CodeBehindDemo" %>
2) Use text editor: <%@ Page inherits=CodeBehind src=codebehind.cs %>

2, EnableViewState
当一个Page不是Post给它自己的时候,ViewState可以设置为false
<%@ Page Language=C# EnableViewState=false %>

3, Control.ViewState可以用来存贮信息

         public String Text

         {

              get

              {

                   return (String) ViewState["Text"];

              }

              set

              {

                   ViewState["Text"] = value;

              }

         }
4, Page 不同阶段的各个事件:
在Load阶段:
1)initialization, 用OnInit method来handle
2)Load,用OnLoad来handle
3)PreRender, this is the phase before output is rendered. handle using OnPreSender
4)Save ViewState: the view state is saved to a hidden value on the page. This can be overriden using SaveViewState method.
5) Render, this page and its controls are render as HTML, can override using the Render method
6) Disponse

在PostBack阶段:
1) Initialization. same as “load“
2) Load ViewState
3) Postback data is loaded
4) Load, same as before “load“
5) Change event are raised
6) Handle postback event
7) PreRender
8) Save viewstate
9) Render
10) Dispose

5, Trace
1)打开Trace, <%@ Page Trace=True %>
2)Both Trace.Write() and Trace.Warn() will create a trace on the trace information. But Trace.Warn() is red color.
3)Open Trace in the application level, in web.config file, add <%trace Enable=true %>
4)After enabled application trace, use http://localhost/app/trace.axd to view the trace.

6,Valicator Control
Asp.Net中支持如下的Valicator Control
1) RequiredFieldValidator Control
2) RangeValidator Control
3) CompareValidator Control
4) RegularExpressionValidator Control
5) CustomValidator Control
CustomValidator Control的一个例子:

                   <asp:CustomValidator id="cvEven" controlToValidate="txtEven" Display="Static"

                        runat="server" ClientValidationFunction="ClientValidator"

                        OnServerValidate="ServerValidator">

Client端的JavaScript Code:
 
<script language="JavaScript">
       function ClientValidator(source, args)
       {
          if (args.Value % 2 == 0)
             args.IsValid=true;
          else
             args.IsValid=false;
          return;
       }
</script>

Server端的Code:

         public void ServerValidator (object source,

              ServerValidateEventArgs e)

         {

              try

              {

                   int evenNumber = Int32.Parse(e.Value);

                   if (evenNumber % 2 == 0)

                       e.IsValid = true;

              }

              catch (Exception)

              {

                   // error handler here

              }

         }