如何正确读取Android上的AsyncStorage

概述似乎可以从Android(本机)访问AsyncStorage;但我仍然在努力做这项工作.在我的ReactNative应用程序中,我有类似的东西：商店constconfig={...}exportconstreducers={...user:user}letrootReducer=combineReducers(reducers)letreducer=persistRedu

似乎可以从Android(本机)访问AsyncStorage;但我仍然在努力做这项工作.

在我的React Native应用程序中,我有类似的东西：

商店

const config = {  ...}export const reducers = {  ...  user: user}let rootReducer = combineReducers(reducers)let reducer = persistReducer(config, rootReducer)

用户减速机

export class Actions {    ...}const initialState = {      first_name: : null,      last_name: : null,      email: null,      addresses: [          { ... }      ]    }  }}export const reducer = (state = initialState, action) => {  switch (action.type) {    ...  }}

从商店获取用户

const user = store.getState().userconsole.log(user.first_name) // Steve...

现在,当我尝试从AndroID获得相同的用户时,问题开始了,我所有的挫败尝试都是这样：

try {    readableDatabase = ReactDatabasesupplier.getInstance(getReactApplicationContext()).getReadableDatabase();    catalystlocalstorage = readableDatabase.query("catalystlocalstorage", new String[]{"value"}, "key = ?", new String[] { "full_name" }, null, null, null);    String[] names = catalystlocalstorage.getColumnnames();    if (catalystlocalstorage.movetoFirst()) {        final String value = catalystlocalstorage.getString(catalystlocalstorage.getColumnIndex("value"));        Log.d(TAG, value);    }} finally {    if (catalystlocalstorage != null) {        catalystlocalstorage.close();    }    if (readableDatabase != null) {        readableDatabase.close();    }}

由于用户是一个对象,我不知道这是否是获取’first_name’的正确方法,我尝试得到’用户’但没有用.

我开始认为我应该使用react-native-sqlite-storage来了解我的数据结构,但我不知道我是否能够在AndroID上访问该数据库.

PS：我想访问AsyncStorage而不是SharedPreferences

lib版本

react-native: 0.48.4redux: 3.7.2redux-persist: 5.4.0

有些问题不起作用

> Access AsyncStorage from native code
> Can I access data stored in React Native’s AsyncStorage from java layer?
> React Native: How to use Java code to fetch data via React Native async storage

解决方法:

AsyncStorage它是一个独特的JsON对象,而我期待的是许多行的键和值;这就是为什么我变空了.

所以首先我继续查询

catalystlocalstorage = readableDatabase.query("catalystlocalstorage", new String[]{"key", "value"}, null, null, null, null, null);

然后我检查以避免空指针

if (catalystlocalstorage.movetoFirst()) {

然后我做了取

do {    // JsONObject will ask for try catch    JsONObject obj = new JsONObject(catalystlocalstorage.getString(catalystlocalstorage.getColumnIndex("value")));} while(catalystlocalstorage.movetoNext());

我相信可能有更好的方法来做到这一点,但是对,我知道我很好.

如果你有更好的想法,请留下你的想法.

UPDATE

import androID.database.Cursor;import androID.database.sqlite.sqliteDatabase;import androID.util.Log;import com.facebook.react.brIDge.ReactApplicationContext;import com.facebook.react.brIDge.ReactContextBaseJavaModule;import com.facebook.react.modules.storage.ReactDatabasesupplier;import org.Json.JsONArray;import org.Json.JsONObject;import java.util.ArrayList;public class AsyncStorage {    public static String TAG = "RNAsyncStorage";    public ReactApplicationContext context;    public ArrayList<JsONObject> collection;    public JsONObject data;    public JsONObject user;    Cursor catalystlocalstorage = null;    sqliteDatabase readableDatabase = null;    public AsyncStorage (ReactApplicationContext context) {        this.context = context;        this.collection = new ArrayList<JsONObject>();        this.fetch();        this.setUser();    }    public voID fetch() {        try {            readableDatabase = ReactDatabasesupplier.getInstance(context).getReadableDatabase();            catalystlocalstorage = readableDatabase.query("catalystlocalstorage", new String[]{"key", "value"}, null, null, null, null, null);            if (catalystlocalstorage.movetoFirst()) {                do {                    try {                        // one row with all AsyncStorage: { "user": { ... }, ... }                        String Json = catalystlocalstorage.getString(catalystlocalstorage.getColumnIndex("value"));                        JsONObject obj = new JsONObject(Json);                        String user = obj.getString("user");                        JsONObject res = new JsONObject();                        res.put("user", new JsONObject(user));                        collection.add(res);                    } catch(Exception e) {                        // do something                    }                } while(catalystlocalstorage.movetoNext());            }        } finally {            if (catalystlocalstorage != null) {                catalystlocalstorage.close();            }            if (readableDatabase != null) {                readableDatabase.close();            }            data = this.collection.get(0);        }    }    public String getFullname () {        try {            return user.getString("fullname");        } catch (Exception e) {            return "";        }    }}

打电话给上课

AsyncStorage as = new AsyncStorage(context);as.getFullname()

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