This is regarding of MDI Forms

Vulpes12y ago

Accepted answer

Try this:

private void checkBox1_CheckedChanged(object sender, EventArgs e)

{

if (checkBox1.Checked && this.MdiParent.MdiChildren.Length == 1)

{

Form2 f2 = new Form2();

f2.MdiParent = this.MdiParent;

f2.Show();

}

}

If you want to close Form1 when you display Form2, then just call : this.Close().

thank you very much. i might need your help future more

you didn't get it. when i'm clicking the checkbox i want to show the form

On check box check change event of form1 use
Form2 childForm = new Form2();
childForm.MdiParent = this;
childForm.Show()