Question

I have a C# form with some types of controls, i throught this code for loop all Labels and re-parent:

private void MakeAllLabelTrans(Control frm, Control parent)
{
    foreach (Control ctl in frm.Controls)
    {
        if (ctl is Label)
        {
            ctl.Parent = parent;
            // ctl.BackColor = Color.Transparent;
        }
        else if (ctl.HasChildren)
        {
            MakeAllLabelTrans(ctl, parent);
        }
    }
}

and call as: MakeAllLabelTrans(this, picBackground); in Form_Load event, but some label was missed (i have puted a messagebox in the loop body – it really not in the loop), but i don’t know why?

Answer 1

You’re changing the collection while enumerating it. This leads to some items being skipped.

You should rewrite this to first build a list of controls that will need to be reparented, and then reparent them in a second pass.