What is Postback and Cross Page Postback in C#asp.net:-
Now I am
going to describe about Postback and
Crosspostback in asp.net.This is the important part for the project.Actually this
is very simple concept. Whenever you develop a website, you have a requirement
to post to other pages also.
Postback:-
Postback means the page posted back
its self after operation.for an example…suppose you have a registration page
and you filled this page than click to the ok button for save.
After click the ok button the message
showed you Your record saved successfully than you press ok button than after
saving the data the page return to same page or your registration page in which
page You ware filling the data but did not move to anather page.This concept is
called postback
Hints:-
Postback contains all information
collected on the Initial page for processing purpose.
Now one question can arise in your
mind that- How can you know whether the page is postback for the first time or
not ?
Ans- The ASP.NET Page
class has a property IsPostBack.
You can check this using IsPostBack.
If(Page.IsPostBack==true)
{
//Your statement
}
Cross
page Postback:-
Cross
page postback is nothing but it is a concept which is responsible to used submit one page (postback1.aspx) controls to another page
(postback2.aspx)
and access those page (postback1.aspx) control values in
another page(postback2.aspx).
Now
I will describe about this concept with simple example .
Now
first create two web application pages postback1.aspx
and postback2.aspx.
Ø
Now open your postback1.aspx page and write this code :-
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
<title>Cross Page Postback Example in asp.net</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<table>
<tr>
<td><b>Name:</b></td>
<td><asp:TextBox ID="txtName"
runat="server"/></td>
</tr>
<tr>
<td><b>Address:</b></td>
<td><asp:TextBox ID="txtAddress"
runat="server"/></td>
</tr>
<tr>
<td> </td>
<td><asp:Button ID="btnPostback"
Text="Postback"
runat="server"
PostBackUrl="~/postback2.aspx"
BackColor="Red"
ForeColor="#0000CC"
onclick="btnPostback_Click"
/> </td>
</tr>
</table>
</div>
</form>
</body>
</html>
Ø
Now open your postback2.aspx page and write this code :-
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
<title>Cross Page Postback Example in asp.net</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<b><u>Welcome to
postback2.aspx Page</u></b><br /><br />
<label id="lblName" runat="server" /><br /><br />
<label id="lblAddress" runat="server" />
</div>
</form>
</body>
</html>
Ø Than write this code at postback2.aspx’s codebehind file(postback.aspx.cs):-
if (PreviousPage
!= null &&
PreviousPage.IsCrossPagePostBack)
{
TextBox txtName = (TextBox)PreviousPage.FindControl("txtName");
TextBox txtAddress = (TextBox)PreviousPage.FindControl("txtAddress");
lblName.InnerText =
"Welcome to postback2.aspx page "
+ txtName.Text;
lblAddress.InnerText
= "Your Address is: "
+txtAddress.Text;
}
else
{
Response.Redirect("postback1.aspx");
}
This is all
about postback and crosspostback concept in asp.net……
Thanks all of
my friends….
Postback means the page posted back its self after operation.Thanks for your valuable information. dot net training in chennai | best dot net training in chennai
ReplyDelete