/**
* 登录界面
*/
public class Login extends Activity implements OnClickListener {
private Button btn_login;
private EditText et_username;
private EditText et_userpwd;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.login);
btn_login = (Button) findViewById(R.id.btn_login);
et_username = (EditText) findViewById(R.id.et_username);
et_username.addT