urgent-Hidden field example

Question

hi friends, Please give examples on hidden field-
1) to store and retrieve text.
2)to increase number on label on every button click by using hidden field.
i have seen various example but all gives incorrect format exception one of the example are-
protected void Page_Load( object sender, EventArgs e)
{
if (HiddenField1.Value != null )
{
int val= Convert.ToInt32(HiddenField1.Value) + 1 ;
HiddenField1.Value = val.ToString();
Label1.Text = val.ToString();
}
}
protected void Button1_Click( object sender, EventArgs e)
{
// this is No Action Button Click
}

Sanjeeb Lenka · Accepted Answer

hi,
in your code hiddenfield value coming as "" which is not equal to "null"
so you can't convert "" to integer thats why exception coming.
i modified your code try this:
protected void Page_Load(object sender, EventArgs e)
{
if (IsPostBack == true)
{
if ( HiddenField1.Value != string.Empty )
{
int val = Convert.ToInt32(HiddenField1.Value) + 1;
HiddenField1.Value = val.ToString();
Label1.Text = val.ToString();
}
else
{
int val = 1;
HiddenField1.Value = val.ToString();
Label1.Text = val.ToString();
}
}
}
protected void Button1_Click(object sender, EventArgs e)
{
}
mark it as answered if it helps you

Arun Kurmi · Answer

Your code fine but why below code give exception
protected void Page_Load(object sender, EventArgs e)
{
if (IsPostBack == true)
{
if (HiddenField1.Value != null)
{
int val = Convert.ToInt32(HiddenField1.Value) + 1;
HiddenField1.Value = val.ToString();
Label1.Text = val.ToString();
}
else
{
int val = 1;
HiddenField1.Value = val.ToString();
Label1.Text = val.ToString();
}
}
}
protected void Button1_Click(object sender, EventArgs e)
{
}

Sanjeeb Lenka · Answer

try this example:
in aspx page:
in .cs page:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
public partial class Default3 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
HiddenField1.Value = "0";
}
}
protected void Button1_Click(object sender, EventArgs e)
{
if (HiddenField1.Value != null)
{
int val = Convert.ToInt32(HiddenField1.Value) + 1;
HiddenField1.Value = val.ToString();
Label1.Text = val.ToString();
}
}
}