Asp. NET in IsPostBack detailed

Original address: http://www.cnblogs.com/carekee/articles/2094723.html

1, IsPostBack Introduction
Page.IsPostBack is a flag: whether the current request is opened for the first time . The call methods are: Page.IsPostBack or IsPostBack or This.ispostback or This.Page.IsPostBack, both of which are equivalent.

1) When opening a URL via IE's address bar, the first time it is opened, the page will no longer be opened for the first time when the server is submitted via the page's submit button or the button that can cause the submission to post. . (the button is loaded once per click)//This is very clear: the address bar opens the URL is the first time , the page button or the event that caused the Submit button is the second time

2) IsPostBack is true only if the first time it is opened is false.

3). NET determines whether a page is opened for the first time: request.form.count>0
4) Each time the page load, according to the need to load each time the code is placed in the IsPostBack, only need to Load the code once to put the IF (! IsPostBack) .

5) Each time the user callbacks the server any information, the IsPostBack property will be raised to determine if this user is

Have you ever done any landing or other events?
6 if (! IsPostBack)
{
Response.Write ("First time submitted!");
}
if (IsPostBack)
{
Response.Write ("press button!");
}

Asp. NET in IsPostBack detailed