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 · 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

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(); } } }

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) { }