This worked:
private void button1_Click(object sender, EventArgs e)
{
System.Threading.Thread.CurrentThread.CurrentUICulture = new System.Globalization.CultureInfo("fr-BE");
ComponentResourceManager resources = new ComponentResourceManager(typeof(Form1));
resources.ApplyResources(this, "$this");
applyResources(resources, this.Controls);
}
private void applyResources(ComponentResourceManager resources, Control.ControlCollection ctls)
{
foreach (Control ctl in ctls)
{
resources.ApplyResources(ctl, ctl.Name);
applyResources(resources, ctl.Controls);
}
}
Be careful to avoid adding whistles like this that nobody will ever use. It at best is a demo feature, in practice users don’t change their native language on-the-fly.