मैं नौसिखिया हूं और अपने SQLite डीबी अद्यतन होने के बाद रीफ्रेश करने के लिए अपने ListView
को अनुमति देने का प्रयास कर रहा हूं। मेरे onResume()
विधि को संशोधित करने के बाद मुझे संकलन त्रुटि प्राप्त नहीं हो रही है। मैं आवश्यकता के लिए SimpleCursorAdapter
का उपयोग कर रहा हूं लेकिन यह काम नहीं कर रहा है। प्राप्त त्रुटि logcat से था और नीचे है। कृपया सलाह दें ... उदाहरण सर्वोत्तम मदद करते हैं।गतिविधि को फिर से शुरू करने में असमर्थ
Logcat:
02-19 21:31:49.933: E/AndroidRuntime(714): java.lang.RuntimeException: Unable to resume activity {com.loginplus.home/com.loginplus.home.LoginList}: java.lang.NullPointerException
02-19 21:31:49.933: E/AndroidRuntime(714): at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2444)
02-19 21:31:49.933: E/AndroidRuntime(714): at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:2472)
02-19 21:31:49.933: E/AndroidRuntime(714): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1986)
02-19 21:31:49.933: E/AndroidRuntime(714): at android.app.ActivityThread.access$600(ActivityThread.java:123)
02-19 21:31:49.933: E/AndroidRuntime(714): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
02-19 21:31:49.933: E/AndroidRuntime(714): at android.os.Handler.dispatchMessage(Handler.java:99)
02-19 21:31:49.933: E/AndroidRuntime(714): at android.os.Looper.loop(Looper.java:137)
02-19 21:31:49.933: E/AndroidRuntime(714): at android.app.ActivityThread.main(ActivityThread.java:4424)
02-19 21:31:49.933: E/AndroidRuntime(714): at java.lang.reflect.Method.invokeNative(Native Method)
02-19 21:31:49.933: E/AndroidRuntime(714): at java.lang.reflect.Method.invoke(Method.java:511)
02-19 21:31:49.933: E/AndroidRuntime(714): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
02-19 21:31:49.933: E/AndroidRuntime(714): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
02-19 21:31:49.933: E/AndroidRuntime(714): at dalvik.system.NativeStart.main(Native Method)
02-19 21:31:49.933: E/AndroidRuntime(714): Caused by: java.lang.NullPointerException
02-19 21:31:49.933: E/AndroidRuntime(714): at com.loginplus.home.LoginList.onResume(LoginList.java:101)
02-19 21:31:49.933: E/AndroidRuntime(714): at android.app.Instrumentation.callActivityOnResume(Instrumentation.java:1154)
02-19 21:31:49.933: E/AndroidRuntime(714): at android.app.Activity.performResume(Activity.java:4539)
02-19 21:31:49.933: E/AndroidRuntime(714): at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2434)
गतिविधि:
public class LoginList extends Activity implements OnClickListener, OnItemClickListener {
private ListView loginList;
private Button webLogin;
private ListAdapter loginListAdapter;
private ArrayList<LoginDetails> loginArrayList;
List<String> arrayList = new ArrayList<String>();
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
arrayList = populateList();
loginListAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, populateList());
setContentView(R.layout.login_listview);
loginList = (ListView)
findViewById(R.id.loginlist);
loginList.setOnItemClickListener(this);
webLogin = (Button)
findViewById(R.id.button3);
webLogin.setOnClickListener(this);
}
@Override
public void onClick (View v) {
Intent webLoginIntent = new Intent (this, LoginPlusActivity.class);
startActivity(webLoginIntent);
}
public List<String> populateList(){
List<String> webNameList = new ArrayList<String>();
dataStore openHelperClass = new dataStore (this);
SQLiteDatabase sqliteDatabase = openHelperClass.getReadableDatabase();
Cursor cursor = sqliteDatabase.query(dataStore.TABLE_NAME_INFOTABLE, null, null, null, null, null, dataStore.COLUMN_NAME_SITE, null);
startManagingCursor(cursor);
while (cursor.moveToNext()){
String sName = cursor.getString(cursor.getColumnIndex(dataStore.COLUMN_NAME_SITE));
String wUrl = cursor.getString(cursor.getColumnIndex(dataStore.COLUMN_NAME_ADDRESS));
String uName = cursor.getString(cursor.getColumnIndex(dataStore.COLUMN_NAME_USERNAME));
String pWord = cursor.getString(cursor.getColumnIndex(dataStore.COLUMN_NAME_PASSWORD));
String lNotes = cursor.getString(cursor.getColumnIndex(dataStore.COLUMN_NAME_NOTES));
LoginDetails lpDetails = new LoginDetails();
lpDetails.setsName(sName);
lpDetails.setwUrl(wUrl);
lpDetails.setuName(uName);
lpDetails.setpWord(pWord);
lpDetails.setlNotes(lNotes);
loginArrayList.add(lpDetails);
webNameList.add(sName);
}
sqliteDatabase.close();
return webNameList;
}
@Override
protected void onResume() {
super.onResume();
loginArrayList.clear();
arrayList.clear();
arrayList = populateList();
dataStore refreshHelper = new dataStore (this);
SQLiteDatabase sqliteDatabase = refreshHelper.getWritableDatabase();
Cursor cursor = sqliteDatabase.query(dataStore.TABLE_NAME_INFOTABLE, null, null, null, null, null, dataStore.COLUMN_NAME_SITE, null);
String[]columns = new String[] { dataStore.COLUMN_NAME_SITE, dataStore.COLUMN_NAME_ADDRESS, dataStore.COLUMN_NAME_USERNAME, dataStore.COLUMN_NAME_PASSWORD, dataStore.COLUMN_NAME_NOTES };
int[] to = new int[]{R.id.rusName, R.id.ruwUrl, R.id.ruuName, R.id.rupWord, R.id.ruNotes};
SimpleCursorAdapter loginListAdapter = new SimpleCursorAdapter(this, android.R.layout.simple_list_item_1, cursor, columns, to);
loginListAdapter.notifyDataSetChanged();
}
@Override
public void onItemClick(AdapterView<?> arg0 , View arg1, int arg2, long arg3) {
Toast.makeText(getApplicationContext(), "Selected ID :" + arg2, Toast.LENGTH_SHORT).show();
Intent updateDeleteLoginInfo = new Intent (this, UpdateDeleteLoginList.class);
LoginDetails clickedObject = loginArrayList.get(arg2);
Bundle loginBundle = new Bundle();
loginBundle.putString("clickedWebSite",clickedObject.getsName());
loginBundle.putString("clickedWebAddress",clickedObject.getwUrl());
loginBundle.putString("clickedUserName",clickedObject.getuName());
loginBundle.putString("clickedPassWord",clickedObject.getpWord());
loginBundle.putString("clickedNotes",clickedObject.getlNotes());
updateDeleteLoginInfo.putExtras(loginBundle);
startActivityForResult(updateDeleteLoginInfo, 0);
}
}
RennoDiniro EditResults:
Logcat:
02-21 23:40:18.419: E/AndroidRuntime(705): FATAL EXCEPTION: main
02-21 23:40:18.419: E/AndroidRuntime(705): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.loginplus.home/com.loginplus.home.LoginList}: java.lang.NullPointerException
02-21 23:40:18.419: E/AndroidRuntime(705): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1956)
02-21 23:40:18.419: E/AndroidRuntime(705): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
02-21 23:40:18.419: E/AndroidRuntime(705): at android.app.ActivityThread.access$600(ActivityThread.java:123)
02-21 23:40:18.419: E/AndroidRuntime(705): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
02-21 23:40:18.419: E/AndroidRuntime(705): at android.os.Handler.dispatchMessage(Handler.java:99)
02-21 23:40:18.419: E/AndroidRuntime(705): at android.os.Looper.loop(Looper.java:137)
02-21 23:40:18.419: E/AndroidRuntime(705): at android.app.ActivityThread.main(ActivityThread.java:4424)
02-21 23:40:18.419: E/AndroidRuntime(705): at java.lang.reflect.Method.invokeNative(Native Method)
02-21 23:40:18.419: E/AndroidRuntime(705): at java.lang.reflect.Method.invoke(Method.java:511)
02-21 23:40:18.419: E/AndroidRuntime(705): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
02-21 23:40:18.419: E/AndroidRuntime(705): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
02-21 23:40:18.419: E/AndroidRuntime(705): at dalvik.system.NativeStart.main(Native Method)
02-21 23:40:18.419: E/AndroidRuntime(705): Caused by: java.lang.NullPointerException
02-21 23:40:18.419: E/AndroidRuntime(705): at com.loginplus.home.LoginList.populateList(LoginList.java:88)
02-21 23:40:18.419: E/AndroidRuntime(705): at com.loginplus.home.LoginList.onCreate(LoginList.java:37)
02-21 23:40:18.419: E/AndroidRuntime(705): at android.app.Activity.performCreate(Activity.java:4465)
02-21 23:40:18.419: E/AndroidRuntime(705): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
02-21 23:40:18.419: E/AndroidRuntime(705): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920)
गतिविधि वर्ग:
012,351, public class LoginList extends Activity implements OnClickListener, OnItemClickListener {
private ListView loginList;
private Button webLogin;
private ListAdapter loginListAdapter;
private ArrayList<LoginDetails> loginArrayList;
List<String> arrayList = new ArrayList<String>();
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
loginListAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, populateList());
arrayList = populateList();
setContentView(R.layout.login_listview);
loginList = (ListView)
findViewById(R.id.loginlist);
loginList.setOnItemClickListener(this);
webLogin = (Button)
findViewById(R.id.button3);
webLogin.setOnClickListener(this);
}
@Override
public void onClick (View v) {
Intent webLoginIntent = new Intent (this, LoginPlusActivity.class);
startActivity(webLoginIntent);
}
public List<String> populateList(){
List<String> webNameList = new ArrayList<String>();
dataStore openHelperClass = new dataStore (this);
SQLiteDatabase sqliteDatabase = openHelperClass.getReadableDatabase();
Cursor cursor = sqliteDatabase.query(dataStore.TABLE_NAME_INFOTABLE, null, null, null, null, null, dataStore.COLUMN_NAME_SITE, null);
startManagingCursor(cursor);
while (cursor.moveToNext()){
String sName = cursor.getString(cursor.getColumnIndex(dataStore.COLUMN_NAME_SITE));
String wUrl = cursor.getString(cursor.getColumnIndex(dataStore.COLUMN_NAME_ADDRESS));
String uName = cursor.getString(cursor.getColumnIndex(dataStore.COLUMN_NAME_USERNAME));
String pWord = cursor.getString(cursor.getColumnIndex(dataStore.COLUMN_NAME_PASSWORD));
String lNotes = cursor.getString(cursor.getColumnIndex(dataStore.COLUMN_NAME_NOTES));
LoginDetails lpDetails = new LoginDetails();
lpDetails.setsName(sName);
lpDetails.setwUrl(wUrl);
lpDetails.setuName(uName);
lpDetails.setpWord(pWord);
lpDetails.setlNotes(lNotes);
loginArrayList.add(lpDetails);
webNameList.add(sName);
}
sqliteDatabase.close();
return webNameList;
}
@Override
protected void onResume() {
super.onResume();
try{
loginArrayList = new ArrayList<LoginDetails>();
arrayList = new ArrayList<String>();
loginArrayList.clear();
arrayList.clear();
arrayList = populateList();
dataStore refreshHelper = new dataStore (this);
SQLiteDatabase sqliteDatabase = refreshHelper.getWritableDatabase();
Cursor cursor = sqliteDatabase.query(dataStore.TABLE_NAME_INFOTABLE, null, null, null, null, null, dataStore.COLUMN_NAME_SITE, null);
String[]columns = new String[] { dataStore.COLUMN_NAME_SITE, dataStore.COLUMN_NAME_ADDRESS, dataStore.COLUMN_NAME_USERNAME, dataStore.COLUMN_NAME_PASSWORD, dataStore.COLUMN_NAME_NOTES };
int[] to = new int[]{R.id.rusName, R.id.ruwUrl, R.id.ruuName, R.id.rupWord, R.id.ruNotes};
SimpleCursorAdapter loginListAdapter = new SimpleCursorAdapter(this, android.R.layout.simple_list_item_1, cursor, columns, to);
loginListAdapter.notifyDataSetChanged();
}catch(Exception e)
{
e.printStackTrace();
}
}
@Override
public void onItemClick(AdapterView<?> arg0 , View arg1, int arg2, long arg3) {
Toast.makeText(getApplicationContext(), "Selected ID :" + arg2, Toast.LENGTH_SHORT).show();
Intent updateDeleteLoginInfo = new Intent (this, UpdateDeleteLoginList.class);
LoginDetails clickedObject = loginArrayList.get(arg2);
Bundle loginBundle = new Bundle();
loginBundle.putString("clickedWebSite",clickedObject.getsName());
loginBundle.putString("clickedWebAddress",clickedObject.getwUrl());
loginBundle.putString("clickedUserName",clickedObject.getuName());
loginBundle.putString("clickedPassWord",clickedObject.getpWord());
loginBundle.putString("clickedNotes",clickedObject.getlNotes());
updateDeleteLoginInfo.putExtras(loginBundle);
startActivityForResult(updateDeleteLoginInfo, 0);
}
}
आपका ऑनपोज़() कहां है? –
आपकी लाइन रीज़्यूम विधि – Nickolaus
में कौन सी पंक्ति 101 है कोई ऑनऑज़() सर्जरी – user1165694