private void frm_process_chain_Load(object sender, EventArgs e)
{
chain_process chain = new chain_process();
Thread.Sleep(500);
chain.text_to_void("Chào bạn, đây là chương trình xử lý văn bản");
}
private void btn_text_void_Click(object sender, EventArgs e)
{
chain_process chain = new chain_process();
txt_output.Text = "time delay few seconds..... \r\n if nothing happens, please click it again! \r\n";
txt_output.Text += chain.text_to_void(txt_input.Text);
}