当我的数据库数据更改时尝试让我的 ListView 刷新时，我的列表视图现在完全空白。项目被添加到数据库中，但它们不再显示在列表视图中。在所有 db 列中，只有一个设置为显示在 listview (sname) 中。我的 Logcat 指向一个重新查询，但我不确定如何进行修复。请指教。
日志猫：
02-19 22:41:41.303: W/SQLiteCursor(1083): requery() failed database /data/data/com.loginplus.home/databases/SiteLogindb (conn# 0) already closed
02-19 22:41:41.303: W/SQLiteCursor(1083): java.lang.IllegalStateException: database /data/data/com.loginplus.home/databases/SiteLogindb (conn# 0) already closed
02-19 22:41:41.303: W/SQLiteCursor(1083): at android.database.sqlite.SQLiteDatabase.verifyDbIsOpen(SQLiteDatabase.java:2082)
02-19 22:41:41.303: W/SQLiteCursor(1083): at android.database.sqlite.SQLiteDatabase.getDbConnection(SQLiteDatabase.java:2407)
02-19 22:41:41.303: W/SQLiteCursor(1083): at android.database.sqlite.SQLiteDatabase.getDatabaseHandle(SQLiteDatabase.java:2388)
02-19 22:41:41.303: W/SQLiteCursor(1083): at android.database.sqlite.SQLiteCursor.requery(SQLiteCursor.java:246)
02-19 22:41:41.303: W/SQLiteCursor(1083): at android.app.Activity.performRestart(Activity.java:4505)
02-19 22:41:41.303: W/SQLiteCursor(1083): at android.app.Activity.performResume(Activity.java:4531)
02-19 22:41:41.303: W/SQLiteCursor(1083): at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2434)
02-19 22:41:41.303: W/SQLiteCursor(1083): at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:2472)
02-19 22:41:41.303: W/SQLiteCursor(1083): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1173)
02-19 22:41:41.303: W/SQLiteCursor(1083): at android.os.Handler.dispatchMessage(Handler.java:99)
02-19 22:41:41.303: W/SQLiteCursor(1083): at android.os.Looper.loop(Looper.java:137)
02-19 22:41:41.303: W/SQLiteCursor(1083): at android.app.ActivityThread.main(ActivityThread.java:4424)
02-19 22:41:41.303: W/SQLiteCursor(1083): at java.lang.reflect.Method.invokeNative(Native Method)
02-19 22:41:41.303: W/SQLiteCursor(1083): at java.lang.reflect.Method.invoke(Method.java:511)
02-19 22:41:41.303: W/SQLiteCursor(1083): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
02-19 22:41:41.303: W/SQLiteCursor(1083): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
02-19 22:41:41.303: W/SQLiteCursor(1083): at dalvik.system.NativeStart.main(Native Method)
02-19 22:41:41.323: W/SQLiteCursor(1083): requery() failed database /data/data/com.loginplus.home/databases/SiteLogindb (conn# 0) already closed
02-19 22:41:41.323: W/SQLiteCursor(1083): java.lang.IllegalStateException: database /data/data/com.loginplus.home/databases/SiteLogindb (conn# 0) already closed
02-19 22:41:41.323: W/SQLiteCursor(1083): at android.database.sqlite.SQLiteDatabase.verifyDbIsOpen(SQLiteDatabase.java:2082)
02-19 22:41:41.323: W/SQLiteCursor(1083): at android.database.sqlite.SQLiteDatabase.getDbConnection(SQLiteDatabase.java:2407)
02-19 22:41:41.323: W/SQLiteCursor(1083): at android.database.sqlite.SQLiteDatabase.getDatabaseHandle(SQLiteDatabase.java:2388)
02-19 22:41:41.323: W/SQLiteCursor(1083): at android.database.sqlite.SQLiteCursor.requery(SQLiteCursor.java:246)
02-19 22:41:41.323: W/SQLiteCursor(1083): at android.app.Activity.performRestart(Activity.java:4505)
02-19 22:41:41.323: W/SQLiteCursor(1083): at android.app.Activity.performResume(Activity.java:4531)
02-19 22:41:41.323: W/SQLiteCursor(1083): at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2434)
02-19 22:41:41.323: W/SQLiteCursor(1083): at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:2472)
02-19 22:41:41.323: W/SQLiteCursor(1083): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1173)
02-19 22:41:41.323: W/SQLiteCursor(1083): at android.os.Handler.dispatchMessage(Handler.java:99)
02-19 22:41:41.323: W/SQLiteCursor(1083): at android.os.Looper.loop(Looper.java:137)
02-19 22:41:41.323: W/SQLiteCursor(1083): at android.app.ActivityThread.main(ActivityThread.java:4424)
02-19 22:41:41.323: W/SQLiteCursor(1083): at java.lang.reflect.Method.invokeNative(Native Method)
02-19 22:41:41.323: W/SQLiteCursor(1083): at java.lang.reflect.Method.invoke(Method.java:511)
02-19 22:41:41.323: W/SQLiteCursor(1083): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
02-19 22:41:41.323: W/SQLiteCursor(1083): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
02-19 22:41:41.323: W/SQLiteCursor(1083): at dalvik.system.NativeStart.main(Native Method)
02-19 22:41:41.343: W/SQLiteCursor(1083): requery() failed database /data/data/com.loginplus.home/databases/SiteLogindb (conn# 0) already closed
02-19 22:41:41.343: W/SQLiteCursor(1083): java.lang.IllegalStateException: database /data/data/com.loginplus.home/databases/SiteLogindb (conn# 0) already closed
02-19 22:41:41.343: W/SQLiteCursor(1083): at android.database.sqlite.SQLiteDatabase.verifyDbIsOpen(SQLiteDatabase.java:2082)
02-19 22:41:41.343: W/SQLiteCursor(1083): at android.database.sqlite.SQLiteDatabase.getDbConnection(SQLiteDatabase.java:2407)
02-19 22:41:41.343: W/SQLiteCursor(1083): at android.database.sqlite.SQLiteDatabase.getDatabaseHandle(SQLiteDatabase.java:2388)
02-19 22:41:41.343: W/SQLiteCursor(1083): at android.database.sqlite.SQLiteCursor.requery(SQLiteCursor.java:246)
02-19 22:41:41.343: W/SQLiteCursor(1083): at android.app.Activity.performRestart(Activity.java:4505)
02-19 22:41:41.343: W/SQLiteCursor(1083): at android.app.Activity.performResume(Activity.java:4531)
02-19 22:41:41.343: W/SQLiteCursor(1083): at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2434)
02-19 22:41:41.343: W/SQLiteCursor(1083): at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:2472)
02-19 22:41:41.343: W/SQLiteCursor(1083): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1173)
02-19 22:41:41.343: W/SQLiteCursor(1083): at android.os.Handler.dispatchMessage(Handler.java:99)
02-19 22:41:41.343: W/SQLiteCursor(1083): at android.os.Looper.loop(Looper.java:137)
02-19 22:41:41.343: W/SQLiteCursor(1083): at android.app.ActivityThread.main(ActivityThread.java:4424)
02-19 22:41:41.343: W/SQLiteCursor(1083): at java.lang.reflect.Method.invokeNative(Native Method)
02-19 22:41:41.343: W/SQLiteCursor(1083): at java.lang.reflect.Method.invoke(Method.java:511)
02-19 22:41:41.343: W/SQLiteCursor(1083): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
02-19 22:41:41.343: W/SQLiteCursor(1083): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
02-19 22:41:41.343: W/SQLiteCursor(1083): at dalvik.system.NativeStart.main(Native Method)
日志猫 2/2513
02-24 20:44:04.032: E/AndroidRuntime(1323): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.loginplus.home/com.loginplus.home.LoginList}: java.lang.NullPointerException
02-24 20:44:04.032: E/AndroidRuntime(1323): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1956)
02-24 20:44:04.032: E/AndroidRuntime(1323): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
02-24 20:44:04.032: E/AndroidRuntime(1323): at android.app.ActivityThread.access$600(ActivityThread.java:123)
02-24 20:44:04.032: E/AndroidRuntime(1323): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
02-24 20:44:04.032: E/AndroidRuntime(1323): at android.os.Handler.dispatchMessage(Handler.java:99)
02-24 20:44:04.032: E/AndroidRuntime(1323): at android.os.Looper.loop(Looper.java:137)
02-24 20:44:04.032: E/AndroidRuntime(1323): at android.app.ActivityThread.main(ActivityThread.java:4424)
02-24 20:44:04.032: E/AndroidRuntime(1323): at java.lang.reflect.Method.invokeNative(Native Method)
02-24 20:44:04.032: E/AndroidRuntime(1323): at java.lang.reflect.Method.invoke(Method.java:511)
02-24 20:44:04.032: E/AndroidRuntime(1323): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
02-24 20:44:04.032: E/AndroidRuntime(1323): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
02-24 20:44:04.032: E/AndroidRuntime(1323): at dalvik.system.NativeStart.main(Native Method)
02-24 20:44:04.032: E/AndroidRuntime(1323): Caused by: java.lang.NullPointerException
02-24 20:44:04.032: E/AndroidRuntime(1323): at com.loginplus.home.LoginList.populateList(LoginList.java:92)
02-24 20:44:04.032: E/AndroidRuntime(1323): at com.loginplus.home.LoginList.onCreate(LoginList.java:41)
02-24 20:44:04.032: E/AndroidRuntime(1323): at android.app.Activity.performCreate(Activity.java:4465)
02-24 20:44:04.032: E/AndroidRuntime(1323): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
02-24 20:44:04.032: E/AndroidRuntime(1323): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920)
活动课：
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); (revised 2/25/13)
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);
}
cursor.close(); //(revised 2/25/13)
return webNameList;
}
@Override
protected void onResume() {
super.onResume();
ArrayList<LoginDetails> loginArrayList = new ArrayList<LoginDetails>();
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);
}
}