Cross-Page Post Back means sending the data from one page to another page.
Example:
CrossPagePostBack.aspx
<%@ Page Language="C#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
</script>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>asp.net cross page postback example</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<h2 style="color:Red">asp.net Cross-Page PostBack example</h2>
<asp:Label
ID="Label1"
runat="server"
Text="ProductID"
ForeColor="DodgerBlue"
>
</asp:Label>
<asp:TextBox
ID="TextBox1"
runat="server"
ForeColor="AliceBlue"
BackColor="DodgerBlue"
>
</asp:TextBox>
<br />
<asp:Label
ID="Label2"
runat="server"
Text="Product Name"
ForeColor="DodgerBlue"
>
</asp:Label>
<asp:TextBox
ID="TextBox2"
runat="server"
ForeColor="AliceBlue"
BackColor="DodgerBlue"
>
</asp:TextBox>
<br />
<asp:Button
ID="Button1"
runat="server"
Text="Submit data"
Font-Bold="true"
ForeColor="DodgerBlue"
PostBackUrl="~/NextPage.aspx"
/>
</div>
</form>
</body>
</html>
NextPage.aspx
<%@ Page Language="C#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
protected void Page_Load(object sender, System.EventArgs e) {
TextBox pvProductID = (TextBox)PreviousPage.FindControl("TextBox1");
TextBox pvProductName = (TextBox)PreviousPage.FindControl("TextBox2");
Label1.Text ="You came from: "+ PreviousPage.Title.ToString();
Label2.Text = "Product ID: " + pvProductID.Text.ToString();
Label2.Text += "<br />Product Name: " + pvProductName.Text.ToString();
string imageSource = "~/Images/" + pvProductID.Text + ".jpg";
Image1.ImageUrl = imageSource;
Image1.BorderWidth = 2;
Image1.BorderColor = System.Drawing.Color.DodgerBlue;
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>asp.net Cross-Page PostBack example: how to submit a page to another page</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<h2 style="color:Teal">asp.net cross page postback example</h2>
<asp:Label ID="Label1" runat="server" ForeColor="Crimson">
</asp:Label>
<br />
<asp:Label ID="Label2" runat="server" ForeColor="SeaGreen">
</asp:Label>
<br />
<asp:Image ID="Image1" runat="server" />
</div>
</form>
</body>
</html>
OUTPUT: