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Detailed introduction to Webform built-in object Session object, Application global object, ViewState

Author：Eve Cole Update Time：2025-07-01 15:00:04

This article is a detailed introduction to the built-in object Session object and Application global object shared by the editor of the Error New Technology Channel. I hope it will be helpful to your future learning.

Session

Each computer accesses the server and has an independent session, the key values ​​are the same, and the contents are different.

1.session is saved on the server.

2. The session has no persistence and the storage period is 20 minutes.

Key points: Don’t abuse the session, don’t use it. Abuse will cause server overflow, and do not use it will cause resource waste.

Assignment: Session["key"] = value;

Value: string a = Session["key"];

Clear: Session["key"]=null;

Application

Application["key"] is that all users get the value in this key. There is no saving cycle, and it will be saved all the time, usually used as the version number.

Assignment: Application["key"]=value;

Value: Application.Get("key");

Repeater's Command Operation:

  1. ItemCommand event—All controls in Repeater that can trigger events will trigger this event
  2. CommandName - determine what button is clicked, e.CommandName
  3. CommandArgument - The primary key value data passed by the trigger event. When the interface value is bound here, use single quotes e.
  4. ItemCreated - Execute this event once in the project template when HTML code is generated
  5. ItemDataBound - The item template executes this event once after the data is bound

example:

 <ItemTemplate> <tr style="<%#Eval("Blue") %>" > <td><%#Eval("UserName") %></td> <td><%#Eval("Password") %></td> <td><%#Eval("NickName") %></td> <td><%#Eval("SexName") %></td> <td><%#Eval("birthdayn" )%></td> <td><%#Eval("Age" )%></td> <td><%#Eval("NationName") %></td> <td><asp:Button ID="Button1" runat="server" Text="Delete" CommandName="delete" CommandArgument='<%#Eval("UserName") %>'/> <asp:Button ID="Button2" runat="server" Text="Modify" CommandName="xiugai" CommandName="delete" CommandArgument='<%#Eval("UserName") %>' /> </td> </tr> </ItemTemplate>

Background code:

 if (e.CommandName == "delete")//Delete button { new UserDA().delete(e.CommandArgument.ToString()); Repeater1.DataSource = new UserDA().select(); Repeater1.DataBind(); } if (e.CommandName == "xiugai") { new UserDA().select(e.CommandArgument.ToString()); Repeater1.DataSource = new UserDA().select(); Repeater1.DataBind(); }

Through the introduction of the new technology channel, the built-in objects of the new technology channel, the Session object of the new technology channel, the ViewState, I hope it can help you learn this part of the knowledge. Thank you for your support of the new technology channel!

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