Layer-3 Structure

"Three-layer structure" is "appearance layer", "business logic layer", and "database layer"
Suppose you want to create a message board in this structure:
# The appearance code of the message board page is stored in the. aspx file.
# When a user clicks the submit button on the page, the text information is first transmitted to a LeaveWord Class Object
(The LeaveWord class definition is encapsulated into the "business logic layer ")
# Then let this object execute Post () to send the message to the database
A simple code is:
<Textarea id = "Content" runat = "server"> </textarea>
<Input type = "button" id = "Post" runat = "server"/>
//----------------------------------------
// On the appearance layer, after the user clicks the send button
//----------------------------------------
Private void Post_ServerClick (object sender, EventArgs e)
{
LeaveWord lword = new LeaveWord ();
Lword. Content = Content. Value;
Lword. Post ();
}
//----------------------------------------
// Define the LeaveWord class at the business logic layer
//----------------------------------------
Public class LeaveWord
{
Public string Content;