Webform built-in object Session object, Application global object, ViewState detailed introduction

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 that can trigger events in Repeater 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 binding the interface value in this article, 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 class=tr_Item 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 this article, I hope it can help you understand. Thank you for your support for this website in this part!