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你能帮我吗？

我已经在包含数据库的 Google Play 商店上创建并发布了该应用程序，我已经在不同的 Android 手机上对其进行了测试。我的应用程序在 Android 版本（Android 10、8、5 等）上完美运行，但在 Android 9 上除外，你知道我该如何解决这个问题吗？我在华为 Smart Z、荣耀 P20、三星 Y6、小米米上发现了这个问题。Play 商店控制台说我的应用程序可以在该模型上运行。我是应用程序开发的初学者。

这发生在我的Huawei Smart上：当我安装应用程序时，当我想进入数据库时​​它会打开并崩溃，当我想再次进入应用程序时它会崩溃并在logcat上：

E/Path 1: data/data/com.gema/databases/ 
E/SQLiteLog: (14) cannot open file at line 36906 of [c255889bd9]
E/SQLiteLog: (14) os_unix.c:36906: (2) open(//data/data/com.gematranslate/databases/gema_recnik.db) - 
E/SQLiteDatabase: Failed to open database 'data/data/com.gematranslate/databases/gema_recnik.db'.
android.database.sqlite.SQLiteCantOpenDatabaseException: unknown error (Sqlite code 14 SQLITE_CANTOPEN): Could not open database, (OS error - 2:No such file or directory)

在android清单中我放了：

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

这是我检查数据库的代码：

public boolean checkDataBase() {
    SQLiteDatabase checkDB = null;
    try {
        String myPath = DB_PATH + DB_NAME;
        checkDB = SQLiteDatabase.openDatabase(myPath,null,SQLiteDatabase.OPEN_READONLY);
        myContext.getDatabasePath(DB_NAME).getPath();
        checkDB.disableWriteAheadLogging();
    } catch (SQLException e)
    {
        //
    }
    if (checkDB!= null){
        checkDB.close();
    }
    return checkDB != null? true : false;

这是我打开数据库的代码：

public void openDataBase() {
    String myPath = DB_PATH + DB_NAME;
    myContext.getDatabasePath(DB_NAME).getPath();
    db = SQLiteDatabase.openDatabase(myPath,null, SQLiteDatabase.OPEN_READWRITE);
    db.disableWriteAheadLogging();

如果有人可以帮助我，非常感谢。

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1 回答 1

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这是所有版本的 Android 都支持的解决方案

public class DataBase extends SQLiteOpenHelper {

private static final int DATABASE_VERSION = 1;
private static final String DATABASE_NAME = "database.db";
private static String DATABASE_PATH = "";
private static String LAST_DATABASE_PATH = "";
private SQLiteDatabase mDataBase;
private final Context ctx;

public DataBase2(@Nullable Context context) {
    super(context, DATABASE_NAME, null, DATABASE_VERSION);
    DATABASE_PATH = context.getDatabasePath(DATABASE_NAME).getPath();
    this.ctx = context;

    if (!checkIfDBExists()) {
        createDataBase();
    }

    File dbFile = new File(Environment.getDataDirectory().getPath()+"/data/"+ BuildConfig.APPLICATION_ID +"/databases");
    if (dbFile.isDirectory()) {
        String[] child = dbFile.list();
        assert child != null;
        for (int i = 0; i < child.length; i++) {
            if (!(child[i].equals("database.db") || child[i].equals(DATABASE_NAME))) {
                new File(dbFile, child[i]).delete();
            }
        }
    }
}

public void createDataBase() {
    this.getReadableDatabase();
    this.close();
    try {
        copyDataBase();
    } catch (Exception e) {
        e.printStackTrace();
    }
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    try {
        File DbFile = ctx.getDatabasePath(DATABASE_NAME);
        if (DbFile.exists()) {
            copyDataBase();
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
}

private boolean checkIfDBExists() {
    File dbFile = new File(DATABASE_PATH);
    return dbFile.exists();
}



public void openDataBase() {
    close();
    mDataBase = SQLiteDatabase.openDatabase(DATABASE_PATH, null, CREATE_IF_NECESSARY);
}

private void copyDataBase() throws IOException {
    InputStream mInput = ctx.getAssets().open("database.db");
    String outfileName = DATABASE_PATH;
    OutputStream mOutput = new FileOutputStream(outfileName);
    byte[] buffer = new byte[1024];
    int mLength;
    while ((mLength = mInput.read(buffer)) > 0) {
        mOutput.write(buffer, 0, mLength);
    }
    mOutput.flush();
    mInput.close();
    mOutput.close();
}

@Override
public void onCreate(SQLiteDatabase db) {
}


@Override
public synchronized void close() {
    if (mDataBase != null)
        mDataBase.close();

    SQLiteDatabase.releaseMemory();
    super.close();
}

}

于 2020-06-01T16:45:08.180 回答