private void encrypt_button_Click(object sender, EventArgs e)
{
string text = unciphered_text_box.Text;
for (int i = 0; i < text.Length; ++i)
{
if (not_allowed_symbol(text[i]))
{
MessageBox.Show("Input only number, syms of specified aphabet or spaces!");
return;
}
}
text = letter_cryptor.encrypt(text);
ciphered_text.Text = numeric_cryptor.encrypt(text);
binary_ciphered_text.Text = get_binary_string(ciphered_text.Text);
}