Question

I’m trying to select all items in checked list box when check box All is checked”
How to get that, here is my code

private void checkBox1_CheckedChanged(object sender, EventArgs e)
{
    if (cbAll.Checked)
    {
        if(clbViruslist.Items.Count > 0)
        {
           // here clbViruslist is the checked list o
           // for(int i=0;i<clbViruslist.Items.Count;i++)
           // clbViruslist.SetSelected(i,true);
           // clbViruslist.SetSelected(0,true ) ;
        }
     }
 }

Answer 1

private void cbAll_CheckedChanged(object sender, EventArgs e)
    {
        if (cbAll.Checked)
        {
            foreach (ListItem item in clbViruslist.Items)
            {
                item.Selected = true;                
            }
        }
    }

or this is much better

private void checkBox1_CheckedChanged(object sender, EventArgs e)
    {
       foreach (ListItem item in clbViruslist.Items)
       {
           item.Selected = checkBox1.Checked;                
       }

    }