重新创建 SQLiteDatabase 错误 Activity
SQLiteDatabase error on recreate Activity
重新创建意图后，我在每个数据库查询中都遇到异常。我想这可能是因为重新创建的方式activity，但不知道如何解决这个问题。
我正在更改语言和暗模式更改后重新创建它。
重新创建时抛出异常 activity:
Attempt to re-open an already-closed object: SQLiteDatabase:
Activity
private lateinit var db: SQLiteDatabase
private lateinit var oh: LOTDatabaseHelper
...
onCreate
...
oh = LOTDatabaseHelper(this)
db = oh.readableDatabase
...
onDestroy
...
db.close()
oh.close()
...
以及我如何重新创建意图
val intent = intent
intent.addFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION)
startActivity(intent)
finish()
编辑：
我发现 Activity 被创建了大约两次，然后留下一个，其余的被销毁。 OnDestroy 似乎适用于所有活动并关闭数据库，这应该是不可能的。
现在我导航到初始屏幕，然后导航到使用数据库的 Activity，一切正常。
那么，当 Activity 被替换为 herself 时，为什么生命周期无法正常工作？
打开一个已经关闭的数据库通常是由不匹配的打开和关闭引起的。
通常解决方法是不打开和关闭数据库（除非特别需要，例如从备份副本恢复数据库，或强制 WAL 检查点备份数据库），而是只打开数据库一次。
通常不需要一直打开和关闭数据库，因为当应用程序完成时，数据库将关闭（您可以随时关闭它最顶层 activity 的 onDestroy）。此外打开数据库是一种资源消耗，所以打开很多是资源 wasteful/inefficient.
- 也许会看到 Android SQLite DB When to Close
我建议删除所有关闭。您可能还希望考虑单例方法，甚至可能在 Helper 中拥有所有数据库功能。
作为一个例子，也许可以考虑：-
帮手DBHelper :-
class LOTDatabaseHelper(context: Context): SQLiteOpenHelper(
context,
DATABASE_NAME,
null,
DATABASE_VERSION) {
companion object {
const val DATABASE_NAME = "my.db"
const val DATABASE_VERSION = 1
@Volatile
private var instance: SQLiteDatabase? = null
fun getInstance(context: Context): SQLiteDatabase {
if (instance == null) {
instance = LOTDatabaseHelper(context).writableDatabase
}
return instance as SQLiteDatabase
}
}
override fun onCreate(db: SQLiteDatabase?) {
db?.execSQL(Table1.CREATE_SQL)
}
override fun onUpgrade(db: SQLiteDatabase?, oldVersion: Int, newVersion: Int) {
TODO("Not yet implemented")
}
override fun onDowngrade(db: SQLiteDatabase?, oldVersion: Int, newVersion: Int) {
super.onDowngrade(db, oldVersion, newVersion)
}
fun insert(name: String): Long {
val cv = ContentValues()
cv.put(Table1.COL_NAME,name)
return instance!!.insert(Table1.TABLE_NAME,null,cv)
}
fun getAllFromTable1() : Cursor {
return instance!!.query(Table1.TABLE_NAME,null,null,null,null,null,"${Table1.COL_NAME} ASC")
}
@SuppressLint("Range")
fun logAll() {
val csr = getAllFromTable1()
var row = 1
val nameix = csr.getColumnIndex(COL_NAME)
while (csr.moveToNext()) {
Log.d("CURSORINFO","Row ${row++} ${COL_NAME} is ${csr.getString(csr.getColumnIndex(
COL_NAME))}")
//val test = csr.getString(csr.getColumnIndex("${COL_NAME}"))
}
csr.close()
}
// Table stuff
class Table1 {
companion object {
const val TABLE_NAME = "table1"
const val COL_ID = BaseColumns._ID
const val COL_NAME = "${TABLE_NAME}_name"
const val CREATE_SQL = "CREATE TABLE IF NOT EXISTS $TABLE_NAME (${COL_ID} INTEGER PRIMARY KEY, $COL_NAME TEXT);"
}
}
}
用于调用第二个 Activity MainActivity 的初始 Activity :-
class MainActivity : AppCompatActivity() {
val TAG = "MAINACTIVITYINFO"
private lateinit var dbother: DBHelper
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
dbother = DBHelper.getInstance(this)!!
dbother.insert("TESTOTHER") // Use the Insert in the DBHelper
/* of course you can still get an SQLiteDatabase */
/* There is very little use getting readable as it gets writable */
/* so get writable is more accurate description */
var sqliteDatabase = dbother.writableDatabase //<<<<<< can be used
logCursorInfo(dbother.allAsCursor)
// NOW Start the other Activity
Log.d(TAG,"starting Activity2")
intent = Intent(this,Activity2::class.java)
startActivity(intent)
Log.d(TAG,"after starting Activity2")
}
override fun onDestroy() {
super.onDestroy()
Log.d("ONDESTROY","On Destroy invoked.")
}
override fun onResume() {
super.onResume()
Log.d(TAG,"On Resume invoked")
dbother = DBHelper.getInstance(this)!!
}
//
@SuppressLint("Range")
fun logCursorInfo(csr: Cursor) {
val nameix = csr.getColumnIndex(LOTDatabaseHelper.Table1.COL_NAME)
val idix = csr.getColumnIndex(LOTDatabaseHelper.Table1.COL_ID)
while (csr.moveToNext()) {
//Log.d(TAG,"${LOTDatabaseHelper.Table1.COL_ID} = ${csr.getString(idix)} ${LOTDatabaseHelper.Table1.COL_NAME} = ${csr.getString(nameix)}")
Log.d(TAG,"${csr.getString(csr.getColumnIndex(LOTDatabaseHelper.Table1.COL_NAME))}")
}
}
companion object {
var counter: Int = 0
}
}
- 这使用了 DBHelper 但获取了一个实例，然后它添加了几行，提取它们然后开始第二个 Activity。
Activity2 您遇到问题的 activity :-
class Activity2 : AppCompatActivity() {
val TAG = "ACTIVITY2INFO"
private lateinit var dbother: DBHelper
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_2)
Log.d(TAG,"Activity 2 Started (onCreate). $this")
dbother = DBHelper.getInstance(this)!! // Get the Database
dbother.insert("TESTOTHER_ACTIVITY2") // Add a row
var csr = dbother.allAsCursor // get All the rows
DatabaseUtils.dumpCursor(csr) // dump the cursor
csr.close() // close the cursor
/* Start another activity (will loop so stop with counter)*/
Log.d(TAG,"Restarting Activity. counter is ${counter++} $this")
if (counter < 3) {
val intent = intent
intent.addFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION)
startActivity(intent) //<<<<<<<<<< RUN 1 Not the Way as starts a new activity
/* Perhaps the following???? */
// this.intent.addFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION)
//this.recreate() //<<<<<<<<<< RUN 2 perhaps the way but no intent
}
Log.d(TAG,"Finishing Activity 2 $this")
finish()
}
companion object {
var counter: Int = 0
}
override fun onResume() {
super.onResume()
Log.d(TAG,"OnResume Invoked. $this")
}
override fun onDestroy() {
super.onDestroy()
Log.d(TAG,"OnDestory (after super call - before db close and helper close. $this)")
Log.d(TAG,"OnDestory (after all. $this)")
}
}
- 这会得到一个 DBHelper 实例，插入一行，提取所有数据，然后启动另一个 activity 注意这会无限循环，因此会出现计数器。
希望评论对您有所帮助。
如您所见，我包含了相当多的日志记录。但是，正如建议的那样，数据库永远不会关闭。
运行 应用程序
这是 运行 应用程序的结果，即日志（来自全新安装）：-
2021-10-06 19:52:50.715 D/DBHELPERINFO: getInstance returning instance a.a.so69454766kotlinsqlite.DBHelper@59860ab
2021-10-06 19:52:50.717 D/MAINACTIVITYINFO: TESTOTHER
2021-10-06 19:52:50.717 D/MAINACTIVITYINFO: starting Activity2
2021-10-06 19:52:50.724 D/MAINACTIVITYINFO: after starting Activity2
2021-10-06 19:52:50.734 D/MAINACTIVITYINFO: On Resume invoked
2021-10-06 19:52:50.734 D/DBHELPERINFO: getInstance returning instance a.a.so69454766kotlinsqlite.DBHelper@59860ab
2021-10-06 19:52:50.848 D/ACTIVITY2INFO: Activity 2 Started (onCreate). a.a.so69454766kotlinsqlite.Activity2@3269902
2021-10-06 19:52:50.848 D/DBHELPERINFO: getInstance returning instance a.a.so69454766kotlinsqlite.DBHelper@59860ab
2021-10-06 19:52:50.850 I/System.out: >>>>> Dumping cursor android.database.sqlite.SQLiteCursor@950aa67
2021-10-06 19:52:50.851 I/System.out: 0 {
2021-10-06 19:52:50.852 I/System.out: _id=1
2021-10-06 19:52:50.852 I/System.out: table1_name=TESTOTHER
2021-10-06 19:52:50.852 I/System.out: }
2021-10-06 19:52:50.852 I/System.out: 1 {
2021-10-06 19:52:50.852 I/System.out: _id=2
2021-10-06 19:52:50.852 I/System.out: table1_name=TESTOTHER_ACTIVITY2
2021-10-06 19:52:50.852 I/System.out: }
2021-10-06 19:52:50.852 I/System.out: <<<<<
2021-10-06 19:52:50.856 D/ACTIVITY2INFO: Restarting Activity. counter is 0 a.a.so69454766kotlinsqlite.Activity2@3269902
2021-10-06 19:52:50.864 D/ACTIVITY2INFO: Finishing Activity 2 a.a.so69454766kotlinsqlite.Activity2@3269902
2021-10-06 19:52:51.020 D/ACTIVITY2INFO: Activity 2 Started (onCreate). a.a.so69454766kotlinsqlite.Activity2@7db7a75
2021-10-06 19:52:51.020 D/DBHELPERINFO: getInstance returning instance a.a.so69454766kotlinsqlite.DBHelper@59860ab
2021-10-06 19:52:51.021 I/System.out: >>>>> Dumping cursor android.database.sqlite.SQLiteCursor@7fc80ae
2021-10-06 19:52:51.021 I/System.out: 0 {
2021-10-06 19:52:51.021 I/System.out: _id=1
2021-10-06 19:52:51.021 I/System.out: table1_name=TESTOTHER
2021-10-06 19:52:51.021 I/System.out: }
2021-10-06 19:52:51.021 I/System.out: 1 {
2021-10-06 19:52:51.021 I/System.out: _id=2
2021-10-06 19:52:51.022 I/System.out: table1_name=TESTOTHER_ACTIVITY2
2021-10-06 19:52:51.022 I/System.out: }
2021-10-06 19:52:51.022 I/System.out: 2 {
2021-10-06 19:52:51.022 I/System.out: _id=3
2021-10-06 19:52:51.022 I/System.out: table1_name=TESTOTHER_ACTIVITY2
2021-10-06 19:52:51.022 I/System.out: }
2021-10-06 19:52:51.022 I/System.out: <<<<<
2021-10-06 19:52:51.023 D/ACTIVITY2INFO: Restarting Activity. counter is 1 a.a.so69454766kotlinsqlite.Activity2@7db7a75
2021-10-06 19:52:51.030 D/ACTIVITY2INFO: Finishing Activity 2 a.a.so69454766kotlinsqlite.Activity2@7db7a75
2021-10-06 19:52:51.081 D/ACTIVITY2INFO: Activity 2 Started (onCreate). a.a.so69454766kotlinsqlite.Activity2@3433874
2021-10-06 19:52:51.081 D/DBHELPERINFO: getInstance returning instance a.a.so69454766kotlinsqlite.DBHelper@59860ab
2021-10-06 19:52:51.082 I/System.out: >>>>> Dumping cursor android.database.sqlite.SQLiteCursor@5c713d1
2021-10-06 19:52:51.082 I/System.out: 0 {
2021-10-06 19:52:51.082 I/System.out: _id=1
2021-10-06 19:52:51.082 I/System.out: table1_name=TESTOTHER
2021-10-06 19:52:51.082 I/System.out: }
2021-10-06 19:52:51.082 I/System.out: 1 {
2021-10-06 19:52:51.083 I/System.out: _id=2
2021-10-06 19:52:51.083 I/System.out: table1_name=TESTOTHER_ACTIVITY2
2021-10-06 19:52:51.083 I/System.out: }
2021-10-06 19:52:51.083 I/System.out: 2 {
2021-10-06 19:52:51.083 I/System.out: _id=3
2021-10-06 19:52:51.083 I/System.out: table1_name=TESTOTHER_ACTIVITY2
2021-10-06 19:52:51.083 I/System.out: }
2021-10-06 19:52:51.083 I/System.out: 3 {
2021-10-06 19:52:51.083 I/System.out: _id=4
2021-10-06 19:52:51.083 I/System.out: table1_name=TESTOTHER_ACTIVITY2
2021-10-06 19:52:51.083 I/System.out: }
2021-10-06 19:52:51.083 I/System.out: <<<<<
2021-10-06 19:52:51.084 D/ACTIVITY2INFO: Restarting Activity. counter is 2 a.a.so69454766kotlinsqlite.Activity2@3433874
2021-10-06 19:52:51.084 D/ACTIVITY2INFO: Finishing Activity 2 a.a.so69454766kotlinsqlite.Activity2@3433874
2021-10-06 19:52:51.097 D/MAINACTIVITYINFO: On Resume invoked
2021-10-06 19:52:51.097 D/DBHELPERINFO: getInstance returning instance a.a.so69454766kotlinsqlite.DBHelper@59860ab
需要注意的一点是，检索到的 DBHelper 实例始终是 DBHelper@59860ab（即单个实例）。
如您所见，Activity 发生的情况是另一个已启动。您可能希望尝试使用注释掉的：-
/* Perhaps the following???? */
// this.intent.addFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION)
//this.recreate() //<<<<<<<<<< RUN 2 perhaps the way but no intent
- 虽然我不确定这是否会达到您想要的效果。
重新创建意图后，我在每个数据库查询中都遇到异常。我想这可能是因为重新创建的方式activity，但不知道如何解决这个问题。
我正在更改语言和暗模式更改后重新创建它。
重新创建时抛出异常 activity:
Attempt to re-open an already-closed object: SQLiteDatabase:
Activity
private lateinit var db: SQLiteDatabase
private lateinit var oh: LOTDatabaseHelper
...
onCreate
...
oh = LOTDatabaseHelper(this)
db = oh.readableDatabase
...
onDestroy
...
db.close()
oh.close()
...
以及我如何重新创建意图
val intent = intent
intent.addFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION)
startActivity(intent)
finish()
编辑：
我发现 Activity 被创建了大约两次，然后留下一个，其余的被销毁。 OnDestroy 似乎适用于所有活动并关闭数据库，这应该是不可能的。
现在我导航到初始屏幕，然后导航到使用数据库的 Activity，一切正常。 那么，当 Activity 被替换为 herself 时，为什么生命周期无法正常工作？
打开一个已经关闭的数据库通常是由不匹配的打开和关闭引起的。
通常解决方法是不打开和关闭数据库（除非特别需要，例如从备份副本恢复数据库，或强制 WAL 检查点备份数据库），而是只打开数据库一次。
通常不需要一直打开和关闭数据库，因为当应用程序完成时，数据库将关闭（您可以随时关闭它最顶层 activity 的 onDestroy）。此外打开数据库是一种资源消耗，所以打开很多是资源 wasteful/inefficient.
- 也许会看到 Android SQLite DB When to Close
我建议删除所有关闭。您可能还希望考虑单例方法，甚至可能在 Helper 中拥有所有数据库功能。
作为一个例子，也许可以考虑：-
帮手DBHelper :-
class LOTDatabaseHelper(context: Context): SQLiteOpenHelper(
context,
DATABASE_NAME,
null,
DATABASE_VERSION) {
companion object {
const val DATABASE_NAME = "my.db"
const val DATABASE_VERSION = 1
@Volatile
private var instance: SQLiteDatabase? = null
fun getInstance(context: Context): SQLiteDatabase {
if (instance == null) {
instance = LOTDatabaseHelper(context).writableDatabase
}
return instance as SQLiteDatabase
}
}
override fun onCreate(db: SQLiteDatabase?) {
db?.execSQL(Table1.CREATE_SQL)
}
override fun onUpgrade(db: SQLiteDatabase?, oldVersion: Int, newVersion: Int) {
TODO("Not yet implemented")
}
override fun onDowngrade(db: SQLiteDatabase?, oldVersion: Int, newVersion: Int) {
super.onDowngrade(db, oldVersion, newVersion)
}
fun insert(name: String): Long {
val cv = ContentValues()
cv.put(Table1.COL_NAME,name)
return instance!!.insert(Table1.TABLE_NAME,null,cv)
}
fun getAllFromTable1() : Cursor {
return instance!!.query(Table1.TABLE_NAME,null,null,null,null,null,"${Table1.COL_NAME} ASC")
}
@SuppressLint("Range")
fun logAll() {
val csr = getAllFromTable1()
var row = 1
val nameix = csr.getColumnIndex(COL_NAME)
while (csr.moveToNext()) {
Log.d("CURSORINFO","Row ${row++} ${COL_NAME} is ${csr.getString(csr.getColumnIndex(
COL_NAME))}")
//val test = csr.getString(csr.getColumnIndex("${COL_NAME}"))
}
csr.close()
}
// Table stuff
class Table1 {
companion object {
const val TABLE_NAME = "table1"
const val COL_ID = BaseColumns._ID
const val COL_NAME = "${TABLE_NAME}_name"
const val CREATE_SQL = "CREATE TABLE IF NOT EXISTS $TABLE_NAME (${COL_ID} INTEGER PRIMARY KEY, $COL_NAME TEXT);"
}
}
}
用于调用第二个 Activity MainActivity 的初始 Activity :-
class MainActivity : AppCompatActivity() {
val TAG = "MAINACTIVITYINFO"
private lateinit var dbother: DBHelper
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
dbother = DBHelper.getInstance(this)!!
dbother.insert("TESTOTHER") // Use the Insert in the DBHelper
/* of course you can still get an SQLiteDatabase */
/* There is very little use getting readable as it gets writable */
/* so get writable is more accurate description */
var sqliteDatabase = dbother.writableDatabase //<<<<<< can be used
logCursorInfo(dbother.allAsCursor)
// NOW Start the other Activity
Log.d(TAG,"starting Activity2")
intent = Intent(this,Activity2::class.java)
startActivity(intent)
Log.d(TAG,"after starting Activity2")
}
override fun onDestroy() {
super.onDestroy()
Log.d("ONDESTROY","On Destroy invoked.")
}
override fun onResume() {
super.onResume()
Log.d(TAG,"On Resume invoked")
dbother = DBHelper.getInstance(this)!!
}
//
@SuppressLint("Range")
fun logCursorInfo(csr: Cursor) {
val nameix = csr.getColumnIndex(LOTDatabaseHelper.Table1.COL_NAME)
val idix = csr.getColumnIndex(LOTDatabaseHelper.Table1.COL_ID)
while (csr.moveToNext()) {
//Log.d(TAG,"${LOTDatabaseHelper.Table1.COL_ID} = ${csr.getString(idix)} ${LOTDatabaseHelper.Table1.COL_NAME} = ${csr.getString(nameix)}")
Log.d(TAG,"${csr.getString(csr.getColumnIndex(LOTDatabaseHelper.Table1.COL_NAME))}")
}
}
companion object {
var counter: Int = 0
}
}
- 这使用了 DBHelper 但获取了一个实例，然后它添加了几行，提取它们然后开始第二个 Activity。
Activity2 您遇到问题的 activity :-
class Activity2 : AppCompatActivity() {
val TAG = "ACTIVITY2INFO"
private lateinit var dbother: DBHelper
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_2)
Log.d(TAG,"Activity 2 Started (onCreate). $this")
dbother = DBHelper.getInstance(this)!! // Get the Database
dbother.insert("TESTOTHER_ACTIVITY2") // Add a row
var csr = dbother.allAsCursor // get All the rows
DatabaseUtils.dumpCursor(csr) // dump the cursor
csr.close() // close the cursor
/* Start another activity (will loop so stop with counter)*/
Log.d(TAG,"Restarting Activity. counter is ${counter++} $this")
if (counter < 3) {
val intent = intent
intent.addFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION)
startActivity(intent) //<<<<<<<<<< RUN 1 Not the Way as starts a new activity
/* Perhaps the following???? */
// this.intent.addFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION)
//this.recreate() //<<<<<<<<<< RUN 2 perhaps the way but no intent
}
Log.d(TAG,"Finishing Activity 2 $this")
finish()
}
companion object {
var counter: Int = 0
}
override fun onResume() {
super.onResume()
Log.d(TAG,"OnResume Invoked. $this")
}
override fun onDestroy() {
super.onDestroy()
Log.d(TAG,"OnDestory (after super call - before db close and helper close. $this)")
Log.d(TAG,"OnDestory (after all. $this)")
}
}
- 这会得到一个 DBHelper 实例，插入一行，提取所有数据，然后启动另一个 activity 注意这会无限循环，因此会出现计数器。
希望评论对您有所帮助。
如您所见，我包含了相当多的日志记录。但是，正如建议的那样，数据库永远不会关闭。
运行 应用程序
这是 运行 应用程序的结果，即日志（来自全新安装）：-
2021-10-06 19:52:50.715 D/DBHELPERINFO: getInstance returning instance a.a.so69454766kotlinsqlite.DBHelper@59860ab
2021-10-06 19:52:50.717 D/MAINACTIVITYINFO: TESTOTHER
2021-10-06 19:52:50.717 D/MAINACTIVITYINFO: starting Activity2
2021-10-06 19:52:50.724 D/MAINACTIVITYINFO: after starting Activity2
2021-10-06 19:52:50.734 D/MAINACTIVITYINFO: On Resume invoked
2021-10-06 19:52:50.734 D/DBHELPERINFO: getInstance returning instance a.a.so69454766kotlinsqlite.DBHelper@59860ab
2021-10-06 19:52:50.848 D/ACTIVITY2INFO: Activity 2 Started (onCreate). a.a.so69454766kotlinsqlite.Activity2@3269902
2021-10-06 19:52:50.848 D/DBHELPERINFO: getInstance returning instance a.a.so69454766kotlinsqlite.DBHelper@59860ab
2021-10-06 19:52:50.850 I/System.out: >>>>> Dumping cursor android.database.sqlite.SQLiteCursor@950aa67
2021-10-06 19:52:50.851 I/System.out: 0 {
2021-10-06 19:52:50.852 I/System.out: _id=1
2021-10-06 19:52:50.852 I/System.out: table1_name=TESTOTHER
2021-10-06 19:52:50.852 I/System.out: }
2021-10-06 19:52:50.852 I/System.out: 1 {
2021-10-06 19:52:50.852 I/System.out: _id=2
2021-10-06 19:52:50.852 I/System.out: table1_name=TESTOTHER_ACTIVITY2
2021-10-06 19:52:50.852 I/System.out: }
2021-10-06 19:52:50.852 I/System.out: <<<<<
2021-10-06 19:52:50.856 D/ACTIVITY2INFO: Restarting Activity. counter is 0 a.a.so69454766kotlinsqlite.Activity2@3269902
2021-10-06 19:52:50.864 D/ACTIVITY2INFO: Finishing Activity 2 a.a.so69454766kotlinsqlite.Activity2@3269902
2021-10-06 19:52:51.020 D/ACTIVITY2INFO: Activity 2 Started (onCreate). a.a.so69454766kotlinsqlite.Activity2@7db7a75
2021-10-06 19:52:51.020 D/DBHELPERINFO: getInstance returning instance a.a.so69454766kotlinsqlite.DBHelper@59860ab
2021-10-06 19:52:51.021 I/System.out: >>>>> Dumping cursor android.database.sqlite.SQLiteCursor@7fc80ae
2021-10-06 19:52:51.021 I/System.out: 0 {
2021-10-06 19:52:51.021 I/System.out: _id=1
2021-10-06 19:52:51.021 I/System.out: table1_name=TESTOTHER
2021-10-06 19:52:51.021 I/System.out: }
2021-10-06 19:52:51.021 I/System.out: 1 {
2021-10-06 19:52:51.021 I/System.out: _id=2
2021-10-06 19:52:51.022 I/System.out: table1_name=TESTOTHER_ACTIVITY2
2021-10-06 19:52:51.022 I/System.out: }
2021-10-06 19:52:51.022 I/System.out: 2 {
2021-10-06 19:52:51.022 I/System.out: _id=3
2021-10-06 19:52:51.022 I/System.out: table1_name=TESTOTHER_ACTIVITY2
2021-10-06 19:52:51.022 I/System.out: }
2021-10-06 19:52:51.022 I/System.out: <<<<<
2021-10-06 19:52:51.023 D/ACTIVITY2INFO: Restarting Activity. counter is 1 a.a.so69454766kotlinsqlite.Activity2@7db7a75
2021-10-06 19:52:51.030 D/ACTIVITY2INFO: Finishing Activity 2 a.a.so69454766kotlinsqlite.Activity2@7db7a75
2021-10-06 19:52:51.081 D/ACTIVITY2INFO: Activity 2 Started (onCreate). a.a.so69454766kotlinsqlite.Activity2@3433874
2021-10-06 19:52:51.081 D/DBHELPERINFO: getInstance returning instance a.a.so69454766kotlinsqlite.DBHelper@59860ab
2021-10-06 19:52:51.082 I/System.out: >>>>> Dumping cursor android.database.sqlite.SQLiteCursor@5c713d1
2021-10-06 19:52:51.082 I/System.out: 0 {
2021-10-06 19:52:51.082 I/System.out: _id=1
2021-10-06 19:52:51.082 I/System.out: table1_name=TESTOTHER
2021-10-06 19:52:51.082 I/System.out: }
2021-10-06 19:52:51.082 I/System.out: 1 {
2021-10-06 19:52:51.083 I/System.out: _id=2
2021-10-06 19:52:51.083 I/System.out: table1_name=TESTOTHER_ACTIVITY2
2021-10-06 19:52:51.083 I/System.out: }
2021-10-06 19:52:51.083 I/System.out: 2 {
2021-10-06 19:52:51.083 I/System.out: _id=3
2021-10-06 19:52:51.083 I/System.out: table1_name=TESTOTHER_ACTIVITY2
2021-10-06 19:52:51.083 I/System.out: }
2021-10-06 19:52:51.083 I/System.out: 3 {
2021-10-06 19:52:51.083 I/System.out: _id=4
2021-10-06 19:52:51.083 I/System.out: table1_name=TESTOTHER_ACTIVITY2
2021-10-06 19:52:51.083 I/System.out: }
2021-10-06 19:52:51.083 I/System.out: <<<<<
2021-10-06 19:52:51.084 D/ACTIVITY2INFO: Restarting Activity. counter is 2 a.a.so69454766kotlinsqlite.Activity2@3433874
2021-10-06 19:52:51.084 D/ACTIVITY2INFO: Finishing Activity 2 a.a.so69454766kotlinsqlite.Activity2@3433874
2021-10-06 19:52:51.097 D/MAINACTIVITYINFO: On Resume invoked
2021-10-06 19:52:51.097 D/DBHELPERINFO: getInstance returning instance a.a.so69454766kotlinsqlite.DBHelper@59860ab
需要注意的一点是，检索到的 DBHelper 实例始终是 DBHelper@59860ab（即单个实例）。
如您所见，Activity 发生的情况是另一个已启动。您可能希望尝试使用注释掉的：-
/* Perhaps the following???? */
// this.intent.addFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION)
//this.recreate() //<<<<<<<<<< RUN 2 perhaps the way but no intent
- 虽然我不确定这是否会达到您想要的效果。