-2
幫我關於android SharedPreferences，我登錄後登錄活動時會設置爲SharedPreferences，但是當設置爲SharedPreferences時總是出錯的空指針。我試着用吐司來表明價值，所有變量都有價值。這是我的活動Android SharedPreferences空指針
public class LoginNewActivity extends Activity {
public SessionManager session;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
TextView toRegister = (TextView) findViewById(R.id.link_to_register);
toRegister.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Intent i = new Intent(getApplicationContext(), RegisterActivity.class);
startActivity(i);
}
});
final EditText etUsnm = (EditText) findViewById(R.id.tuserid);
final EditText etPswd = (EditText) findViewById(R.id.tpasswd);
Button bLogin = (Button) findViewById(R.id.btnLogin);
bLogin.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
String username = etUsnm.getText().toString();
String password = etPswd.getText().toString();
new UserLoginTask().execute(username, password);
}
});
}
public class UserLoginTask extends AsyncTask<String, String, JSONObject> {
ProgressDialog pdLoading = new ProgressDialog(LoginNewActivity.this);
HttpURLConnection conn;
URL url = null;
JSONParser jsonParser = new JSONParser();
private static final String TAG_MESSAGE = "message";
private static final String TAG_NAMA = "nama_user";
private static final String TAG_USERNAME = "username";
private static final String TAG_HAKAKSES = "role";
private static final String TAG_ERROR = "error";
private static final String LOGIN_URL = "http://192.168.1.101/mlls/getLoginNew.php";
@Override
protected void onPreExecute() {
super.onPreExecute();
//this method will be running on UI thread
pdLoading.setMessage("\tLoading...");
pdLoading.setCancelable(false);
pdLoading.show();
}
@Override
protected JSONObject doInBackground(String... args) {
try {
HashMap<String, String> params = new HashMap<>();
params.put("username", args[0]);
params.put("password", args[1]);
Log.d("request", "starting");
JSONObject json = jsonParser.makeHttpRequest(
LOGIN_URL, "POST", params);
if (json != null) {
Log.d("JSON result", json.toString());
return json;
}
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
protected void onPostExecute(JSONObject json) {
String nama = "";
int iduser = 0;
String email = "";
String hakakses = "";
int error_message = 0;
if (json != null) {
//Toast.makeText(LoginActivity.this, json.toString(),
//Toast.LENGTH_LONG).show();
try {
nama = json.getString(TAG_NAMA);
email = json.getString(TAG_USERNAME);
hakakses = json.getString(TAG_HAKAKSES);
error_message = json.getInt(TAG_ERROR);
} catch (JSONException e) {
e.printStackTrace();
}
}
if(error_message == 1) {
pdLoading.dismiss();
session.setLogin(true);
session.setStatus(hakakses);
session.setNama(nama);
session.setUsername(email);
session.setId(iduser);
Toast.makeText(LoginNewActivity.this, hakakses,
Toast.LENGTH_LONG).show();
//Intent intent = new Intent(LoginNewActivity.this, LessonListActivity.class);
//intent.putExtra("nama", nama);
//intent.putExtra("email", email);
//intent.putExtra("hakakses", hakakses);
//startActivity(intent);
//LoginNewActivity.this.finish();
}else{
Toast.makeText(getApplicationContext(), "User ID atau Password anda salah.", Toast.LENGTH_LONG).show();
}
}
}}
，這是我sharedPreferences
public class SessionManager {
private static String TAG = SessionManager.class.getSimpleName();
SharedPreferences pref;
Editor editor;
Context _context;
int PRIVATE_MODE = 0;
private static final String PREF_NAME = "Hlls";
private static final String KEY_IS_LOGGEDIN = "isLoggenIn";
private static final String KEY_IS_USER = "isStatus";
private static final String KEY_IS_NAMA = "isNama";
private static final String KEY_IS_USERNAME = "isUsername";
private static final String KEY_IS_IDUSER = "isIdUser";
public SessionManager(Context context){
this._context = context;
pref = _context.getSharedPreferences(PREF_NAME, PRIVATE_MODE);
editor = pref.edit();
}
public void setLogin(boolean isLoggedIn){
editor.putBoolean(KEY_IS_LOGGEDIN, isLoggedIn);
editor.commit();
Log.d(TAG, "User login session modified");
}
public void setId(int isIdUser){
editor.putInt(KEY_IS_IDUSER, isIdUser);
editor.commit();
Log.d(TAG, "ID User akses session modified");
}
public void setStatus(String isStatus){
editor.putString(KEY_IS_USER, isStatus);
editor.commit();
Log.d(TAG, "User akses session modified");
}
public void setNama(String isNama){
editor.putString(KEY_IS_NAMA, isNama);
editor.commit();
Log.d(TAG, "Username session modified");
}
public void setUsername(String isUsername){
editor.putString(KEY_IS_USERNAME, isUsername);
editor.commit();
Log.d(TAG, "Username session modified");
}
public String isNama(){
return pref.getString(KEY_IS_NAMA, "");
}
public int isId(){
return pref.getInt(KEY_IS_IDUSER, 0);
}
public String isUsername(){
return pref.getString(KEY_IS_USERNAME, "");
}
public boolean isLoggedIn(){
return pref.getBoolean(KEY_IS_LOGGEDIN, false);
}
public String isStatus(){
return pref.getString(KEY_IS_USER, "");
}
}
幫我這個錯誤，對不起，英語不好
你不會創建'session'，只能使用它。 –