private void but_login_Click(object sender, EventArgs e) { if (!checkBox_remember.Checked) { try { if (System.IO.File.Exists(path)) { System.IO.File.Delete(path); } } catch (Exception ex) { MessageBox.Show(ex.Message); } } access_key = text_sAPI_Key.Text; secret_key = text_sAPI_Secret.Text; ApiData apiData = new ApiData(access_key, secret_key); Program.Accesskey = access_key; Program.Secretkey = secret_key; int ret = apiData.checkApiKey(); if (ret < 0) { MessageBox.Show("Invalid API key, check keys"); return; } if (checkBox_remember.Checked) { try { System.IO.File.WriteAllText(path, ""); System.IO.File.AppendAllText(path, text_sAPI_Key.Text + Environment.NewLine); System.IO.File.AppendAllText(path, text_sAPI_Secret.Text + Environment.NewLine); } catch (Exception ex) { MessageBox.Show(ex.Message); } } isGood = true; Close(); }