Question

I have 2 forms : Form1, Form2.
Form1 has checkedlistbox : checkedlistbox1

All i need is when i click a button from Form2 then checkedlistbox item should be clear.
From searching i found and applied this code but didn’t work.

using (Form1 form1 = new Form1())
      {
          form1.checkedListBox1.Items.Clear();
      }

but didn’t work.
Please suggest some ideas.

Answer 1

Because when you do

using (Form1 form1 = new Form1())

you are actually creating a new instance of Form1. That’s why it won’t work. You need to get the current instance of Form1.

foreach (var item in Application.OpenForms)
{
    Form1 form1 = item as Form1;
    if (form1 != null)
    {
        form1.checkedListBox1.Items.Clear();
    }
}

or probably

((Form1) Application.OpenForms["Form1"]).checkedListBox1.Items.Clear();