投稿
  1. 首页
  2. app

Android 数据存储之ContentProvider 使用和应用场景

crsky • 2022-5-28 • app • 阅读 26

Android 数据存储之ContentProvider 使用和应用场景,第1张

概述备注：ContentProvider1进程一代码：https://github.com/zengyuan/ContentProvider1ModeContentProvider1进程二代码：https://github.com/zengyuan/ContentProvider2ModeAndroidService启动方式，生命周期和应用场景详解: https://www.cnblogs.com/finn21/p/11652482.h

备注：

　　ContentProvIDer1进程一代码：https://github.com/zengyuan/ContentProvider1Mode

　　ContentProvIDer1进程二代码：https://github.com/zengyuan/ContentProvider2Mode

　　AndroID Service 启动方式，生命周期和应用场景详解: https://www.cnblogs.com/finn21/p/11652482.html

　　iOS APP打包上传审核和 客服咨询流程（审核被拒，账号问题等）:https://www.cnblogs.com/finn21/p/11084272.html

注意，最主要是provIDer的配置，以及URl的provIDer地址要相同；

一，ContentProvIDer 主要用于不同的应用程序之间实现数据共享功能！

        主要分为6个：

　　1.使用sqlite技术，创建好数据库和数据表；
　　2.新建类继承ContentProvIDer，重写6个抽象方法（通过这六个方法对数据库进行 *** 作）；
　　3.在Manifest中注册provIDer；
　　4.创建UriMatcher，定义Uri规则，添加注册数据库链表的名称；
　　5.ContentResolver对ContentProvIDer中共享的数据进行增删改查 *** 作；
　　6.获取数据并修改等（进程一进程二增删改查方式一样）；

 

二，进程一代码伺候：

　　　　第一步创建数据库（SQL语句直接执行的）：

package com.saiyi.contentprovIDerdemo1;import androID.content.Context;import androID.database.sqlite.sqliteDatabase;import androID.database.sqlite.sqliteOpenHelper;/** * <pre> *     author : Finn *     e-mail : 892603597@qq.com *     time   : 2019/10/14 *     desc   : https://www.cnblogs.com/finn21/ * </pre> */public class DBHelper extends sqliteOpenHelper {    // 数据库名    private static final String DATABASE_name = "Finn.db";    // 链表名称    public static final String USER_table_name = "user";    public static final String JOB_table_name = "job";    private static final int DATABASE_VERSION = 1;    //数据库版本号    public DBHelper(Context context) {        super(context,DATABASE_name, null, DATABASE_VERSION);    }    @OverrIDe    public voID onCreate(sqliteDatabase db) {        // 创建两个表格:用户表 和职业表        db.execsql("CREATE table IF NOT EXISTS " + USER_table_name + "(_ID INTEGER PRIMARY KEY autoINCREMENT," + " name TEXT)");        db.execsql("CREATE table IF NOT EXISTS " + JOB_table_name + "(_ID INTEGER PRIMARY KEY autoINCREMENT," + " job TEXT)");    }    @OverrIDe    public voID onUpgrade(sqliteDatabase db, int oldVersion, int newVersion) {    }    @OverrIDe    public voID onopen(sqliteDatabase db) {        super.onopen(db);    }    @OverrIDe    public synchronized voID close() {        super.close();    }}

　　　　第一步创建数据库（通过自行封装之后的数据库）：

　　　　

package com.saiyi.contentprovIDerdemo1;import androID.content.Context;import androID.database.sqlite.sqliteDatabase;import androID.database.sqlite.sqliteOpenHelper;/** * <pre> *     author : Finn *     e-mail : 892603597@qq.com *     time   : 2019/10/14 *     desc   : https://www.cnblogs.com/finn21/ * </pre> */public class MyDataBaseHelper extends sqliteOpenHelper {    private static final String DATABASE_name = "KfbFinnSS.db";    private static final int DATABASE_VERSION = 1;    public static final String USER_ID = "userID_ID";// 自动增长表ID    /***.用户名（存储车型af）**/    public static final String table_USER_AF = "table_user_af";    public static final String USER_USER_AF = "car_user_name_af";//用户名    public static final String USER_CAR_AZ_AF = "car_user_az_af";//字符分段    public static final String USER_CAR_name_AF = "car_kfb_name_af";// 车名称    public static final String USER_CAR_TYPE_AF = "car_user_cartype_af";// 车型号    public static final String USER_CAR_DATE_AF = "car_kfb_date_af";// 年份    public static final String USER_CAR_LENGM_AF = "car_kfb_lengmei_af";// 冷媒量    public MyDataBaseHelper(Context context) {        super(context,DATABASE_name, null, DATABASE_VERSION);    }    @OverrIDe    public voID onCreate(sqliteDatabase db) {/** AF * */        db.execsql("CREATE table " + table_USER_AF + " (" + USER_ID + " INTEGER PRIMARY KEY," + USER_USER_AF + " INTEGER NOT Null,"                + USER_CAR_AZ_AF + " TEXT,"  + USER_CAR_name_AF + " TEXT," + USER_CAR_TYPE_AF                + " TEXT," + USER_CAR_DATE_AF + " TEXT NOT Null,"  + USER_CAR_LENGM_AF + " INTEGER default 0);");    }    @OverrIDe    public voID onUpgrade(sqliteDatabase db, int oldVersion, int newVersion) {        //数据库升级启动该方法    }    @OverrIDe    public synchronized voID close() {        super.close();    }    @OverrIDe    public voID onopen(sqliteDatabase db) {        super.onopen(db);    }}

　　　　

package com.saiyi.contentprovIDerdemo1;import androID.content.ContentValues;import androID.content.Context;import androID.database.Cursor;import androID.database.sqlite.sqliteDatabase;import java.util.ArrayList;import java.util.List;/** * <pre> *     author : Finn *     e-mail : 892603597@qq.com *     time   : 2019/10/14 *     desc   : https://www.cnblogs.com/finn21/ * </pre> */public class MyDataBase {    private static final String TAG = MyDataBase.class.getSimplename();    private static MyDataBaseHelper databaseHelper;    private static MyDataBase mydisplacementBase;    private static String USER_name = "13006602877";    private static String table_USER_name = "KFB";    private MyDataBase(Context context) {        databaseHelper = new MyDataBaseHelper(context);    }    public static MyDataBase getInstance(Context context) {        if (mydisplacementBase == null) {            mydisplacementBase = new MyDataBase(context.getApplicationContext());        }        return mydisplacementBase;    }    /**     * 关闭当前的db     *     * @param db     */    synchronized voID closesqlDB(sqliteDatabase db) {        sqliteDatabase.releaseMemory();        if (db != null && db.isopen()) {            db.close();            db = null;        }    }    /**     * 通知本地数据库有变化     */    public interface InotifyDBhasChange {        int CODE_ERR_REPET = 0;        voID onChange(Object... obj);        voID err(int... code);    }    /**     * --------------------------------------添加车名AF---------------------------------------     */    public synchronized voID InsertCaraF(CarInfo info) {        sqliteDatabase writeDB = databaseHelper.getWritableDatabase();        Cursor cursor = writeDB.query(MyDataBaseHelper.table_USER_AF,                new String[]{MyDataBaseHelper.USER_ID},                MyDataBaseHelper.USER_USER_AF + " = ? ",                new String[]{table_USER_name}, null, null, null);        cursor.close();        ContentValues cv = new ContentValues();        cv.put(MyDataBaseHelper.USER_USER_AF, table_USER_name);        cv.put(MyDataBaseHelper.USER_CAR_AZ_AF, info.getAz());        cv.put(MyDataBaseHelper.USER_CAR_name_AF, info.getCarname());        cv.put(MyDataBaseHelper.USER_CAR_TYPE_AF, info.getCarType());        cv.put(MyDataBaseHelper.USER_CAR_DATE_AF, info.getCarDate());        cv.put(MyDataBaseHelper.USER_CAR_LENGM_AF, info.getCarLengM());        try {            writeDB.insert(MyDataBaseHelper.table_USER_AF, null, cv);//插入数据        } catch (Exception e) {            return;        } finally {            closesqlDB(writeDB);        }    }    /**     * 查询所有用户     */    public synchronized List<CarInfo> queryListAF() {        List<CarInfo> List = new ArrayList<>();        sqliteDatabase readDB = databaseHelper.getReadableDatabase();        Cursor cursor = readDB.query(MyDataBaseHelper.table_USER_AF,                null, MyDataBaseHelper.USER_USER_AF + " = ? ",                new String[]{table_USER_name}, null,                null, MyDataBaseHelper.USER_ID, null);        try {//            int user = cursor.getColumnIndex(MyDataBaseHelper.USER_USER_AF);            int pswd = cursor.getColumnIndex(MyDataBaseHelper.USER_CAR_AZ_AF);            int icon = cursor.getColumnIndex(MyDataBaseHelper.USER_CAR_name_AF);            int nickname = cursor.getColumnIndex(MyDataBaseHelper.USER_CAR_TYPE_AF);            int vertion = cursor.getColumnIndex(MyDataBaseHelper.USER_CAR_DATE_AF);            int veron = cursor.getColumnIndex(MyDataBaseHelper.USER_CAR_LENGM_AF);            while (cursor.movetoNext()) {                CarInfo info = new CarInfo(                        cursor.getString(pswd),                        cursor.getString(icon),                        cursor.getString(nickname),                        cursor.getString(vertion),                        cursor.getString(veron)                );                List.add(info);            }        } catch (Exception e) {        } finally {            if (cursor != null) {                cursor.close();            }            closesqlDB(readDB);        }        return List;    }    public Cursor cursor;    public sqliteDatabase readDB;    public synchronized Cursor queryCursor() {        readDB = databaseHelper.getReadableDatabase();        cursor = readDB.query(MyDataBaseHelper.table_USER_AF,                null, MyDataBaseHelper.USER_USER_AF + " = ? ",                new String[]{table_USER_name}, null,                null, MyDataBaseHelper.USER_ID, null);        return cursor;    }    public synchronized voID CloseCursor() {        if (cursor != null) {            cursor.close();        }        closesqlDB(readDB);    }    /**     * 查询所有用户     */    public synchronized Cursor queryListAFA() {        sqliteDatabase readDB = databaseHelper.getReadableDatabase();        Cursor cursor = readDB.query(MyDataBaseHelper.table_USER_AF,                null, MyDataBaseHelper.USER_USER_AF + " = ? ",                new String[]{table_USER_name}, null,                null, MyDataBaseHelper.USER_ID, null);        try {        } catch (Exception e) {        } finally {            if (cursor != null) {                cursor.close();            }            closesqlDB(readDB);        }        return cursor;    }    /**     * 查询AF特定名称的车类型     */    public synchronized List<CarInfo> queryListAFCarname(String Carname) {        List<CarInfo> List = new ArrayList<>();        sqliteDatabase readDB = databaseHelper.getReadableDatabase();        Cursor cursor = readDB.query(MyDataBaseHelper.table_USER_AF,                null, MyDataBaseHelper.USER_USER_AF + " = ? and " + MyDataBaseHelper.USER_CAR_name_AF + " = ? ",                new String[]{table_USER_name, Carname}, null,                null, MyDataBaseHelper.USER_ID, null);        try {//            int user = cursor.getColumnIndex(MyDataBaseHelper.USER_USER_AF);            int pswd = cursor.getColumnIndex(MyDataBaseHelper.USER_CAR_AZ_AF);            int icon = cursor.getColumnIndex(MyDataBaseHelper.USER_CAR_name_AF);            int nickname = cursor.getColumnIndex(MyDataBaseHelper.USER_CAR_TYPE_AF);            int vertion = cursor.getColumnIndex(MyDataBaseHelper.USER_CAR_DATE_AF);            int veron = cursor.getColumnIndex(MyDataBaseHelper.USER_CAR_LENGM_AF);            while (cursor.movetoNext()) {                CarInfo info = new CarInfo(                        cursor.getString(pswd),                        cursor.getString(icon),                        cursor.getString(nickname),                        cursor.getString(vertion),                        cursor.getString(veron)                );                List.add(info);            }        } catch (Exception e) {        } finally {            if (cursor != null) {                cursor.close();            }            closesqlDB(readDB);        }        return List;    }    /**     * 查询AF特定名称和车类型 的生产年份     */    public synchronized List<CarInfo> queryListAFCarnameYeas(String Carname,String CarType) {        List<CarInfo> List = new ArrayList<>();        sqliteDatabase readDB = databaseHelper.getReadableDatabase();        Cursor cursor = readDB.query(MyDataBaseHelper.table_USER_AF,                null, MyDataBaseHelper.USER_USER_AF + " = ? and "                        + MyDataBaseHelper.USER_CAR_name_AF + " = ? and "                        + MyDataBaseHelper.USER_CAR_TYPE_AF + " = ? ",                new String[]{table_USER_name, Carname,CarType}, null,                null, MyDataBaseHelper.USER_ID, null);        try {//            int user = cursor.getColumnIndex(MyDataBaseHelper.USER_USER_AF);            int pswd = cursor.getColumnIndex(MyDataBaseHelper.USER_CAR_AZ_AF);            int icon = cursor.getColumnIndex(MyDataBaseHelper.USER_CAR_name_AF);            int nickname = cursor.getColumnIndex(MyDataBaseHelper.USER_CAR_TYPE_AF);            int vertion = cursor.getColumnIndex(MyDataBaseHelper.USER_CAR_DATE_AF);            int veron = cursor.getColumnIndex(MyDataBaseHelper.USER_CAR_LENGM_AF);            while (cursor.movetoNext()) {                CarInfo info = new CarInfo(                        cursor.getString(pswd),                        cursor.getString(icon),                        cursor.getString(nickname),                        cursor.getString(vertion),                        cursor.getString(veron)                );                List.add(info);            }        } catch (Exception e) {        } finally {            if (cursor != null) {                cursor.close();            }            closesqlDB(readDB);        }        return List;    }    /**     * 删除列表数据     */    public synchronized voID DeletInfoAF(InotifyDBhasChange dbChange) {        sqliteDatabase writeDB = databaseHelper.getWritableDatabase();        try {            writeDB.delete(                    MyDataBaseHelper.table_USER_AF,                    MyDataBaseHelper.USER_USER_AF + " = ? "                    , new String[]{table_USER_name});        } catch (Exception e) {            dbChange.err();            return;        } finally {            closesqlDB(writeDB);        }        dbChange.onChange();    }}

　　第二步：2.新建类继承ContentProvIDer，重写6个抽象方法

　　

package com.saiyi.contentprovIDerdemo1;import androID.content.ContentProvIDer;import androID.content.ContentValues;import androID.content.Context;import androID.content.UriMatcher;import androID.database.Cursor;import androID.database.sqlite.sqliteDatabase;import androID.net.Uri;import androID.util.Log;/** * <pre> *     author : Finn *     e-mail : 892603597@qq.com *     time   : 2019/10/14 *     desc   : https://www.cnblogs.com/finn21/ * </pre> */public class BaseContentProvIDer extends ContentProvIDer{    private Context mContext;    DBHelper mDbHelper = null;    sqliteDatabase db = null;    public static final String autoHORITY = "Finn.zy.myprovIDer";    // 设置ContentProvIDer的唯一标识    public static final int User_Code = 1;    public static final int Job_Code = 2;    public static final int AF_Code = 32;    // UriMatcher类使用:在ContentProvIDer 中注册URI    private static final UriMatcher mMatcher;    public static DataBaseMonitor mListener = null;    public static voID setDataBaseMonitorListener(DataBaseMonitor Listener) {        mListener = Listener;    }    static{        mMatcher = new UriMatcher(UriMatcher.NO_MATCH);        // 初始化        mMatcher.addURI(autoHORITY,DBHelper.USER_table_name, User_Code); // 若URI资源路径 = "content://" + autoHORITY +"/user"        mMatcher.addURI(autoHORITY, DBHelper.JOB_table_name, Job_Code);// 若URI资源路径 = "content://" + autoHORITY +"/job"        mMatcher.addURI(autoHORITY, MyDataBaseHelper.table_USER_AF, AF_Code);// 若URI资源路径 = "content://" + autoHORITY +"/job"        // 固定前缀 "content://" + autoHORITY，数据库链表的名称，则返回注册码User_Code        //固定前缀 "content://" + autoHORITY ，数据库链表的名称，则返回注册码Job_Code    }    // 以下是ContentProvIDer的6个方法    @OverrIDe    public boolean onCreate() {        //该方法在ContentProvIDer创建后就会被调用，AndroID开机后，        // ContentProvIDer在其它应用第一次访问它时才会被创建，同时，要讲返回值修改成true。        mContext = getContext();        // 在ContentProvIDer创建时对数据库进行初始化        // 运行在主线程，故不能做耗时 *** 作,此处仅作展示        mDbHelper = new DBHelper(getContext());        db = mDbHelper.getWritableDatabase();        // 初始化两个表的数据(先清空两个表,再各加入一个记录)        db.execsql("delete from user");        db.execsql("insert into user values(1,'Carson');");        db.execsql("insert into user values(2,'Kobe');");        MyDataBase.getInstance(mContext).InsertCaraF(new CarInfo("宝马","奔驰","路虎","宾利","保时捷"));        MyDataBase.getInstance(mContext).InsertCaraF(new CarInfo("宝马1","奔驰2","路虎3","宾利4","保时捷5"));        return true;    }    public static final int ITEMS = 1;    public static final int ITEMS_ID = 2;//    如果 *** 作的数据属于集合类型，那么MIME类型字符串应该以vnd.androID.cursor.dir/开头。//    例如：要得到所有person记录的Uri为content://com.cfox.contentprovID.PersonProvIDer/person//    那么返回的MIME类型字符串应该为："vnd.androID.cursor.dir/person"    //    如果要 *** 作的数据属于非集合类型数据，那么MIME类型字符串应该以vnd.androID.cursor.item/开头//    例如：得到ID为10的person记录，Uri为content://com.cfox.contentprovID.PersonProvIDer/person/10//    那么返回的MIME类型字符串为："vnd.androID.cursor.item/person"    @OverrIDe    public String getType(Uri uri) {        return null;    }    @OverrIDe    public Uri insert(Uri uri, ContentValues values) {        //该方法用于供外部应用往ContentProvIDer添加数据。        // 根据URI匹配 URI_CODE，从而匹配ContentProvIDer中相应的表名        // 该方法在最下面        String table = gettablename(uri);        Log.e("sdfsdf",table+"====="+MyDataBaseHelper.table_USER_AF);        if(table != null && !MyDataBaseHelper.table_USER_AF.equals(table)){            // 向该表添加数据            db.insert(table, null, values);            // 当该URI的ContentProvIDer数据发生变化时，通知外界（即访问该ContentProvIDer数据的访问者）            mContext.getContentResolver().notifyChange(uri, null);            return uri;        }else{            FinnInsert(uri,values);            return uri;        }//        // 通过ContentUris类从URL中获取ID//        long personID = ContentUris.parseID(uri);//        System.out.println(personID);    }    @OverrIDe    public int delete(Uri uri, String selection, String[] selectionArgs) {        //该方法用于供外部应用从ContentProvIDer删除数据。        String tablename = gettablename(uri);        if(!MyDataBaseHelper.table_USER_AF.equals(tablename)){            //使用原生函数的数据库            return 0;        }else{            //使用封装之后的数据库            return 0;        }    }    @OverrIDe    public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {        return 0;    }    /**     * 查询数据     */    @OverrIDe    public Cursor query(Uri uri, String[] projection, String selection,                        String[] selectionArgs, String sortOrder) {        //该方法用于供外部应用从ContentProvIDer中获取数据。        // 根据URI匹配 URI_CODE，从而匹配ContentProvIDer中相应的表名        // 该方法在最下面        String tablename = gettablename(uri);        Finnquery(tablename);//        // 通过ContentUris类从URL中获取ID//        long personID = ContentUris.parseID(uri);//        System.out.println(personID);        // 查询数据+        if(!MyDataBaseHelper.table_USER_AF.equals(tablename)){            //使用原生函数的数据库            return db.query(tablename,projection,selection,selectionArgs,null,null,sortOrder,null);        }else{            //使用封装之后的数据库            return  MyDataBase.getInstance(mContext).queryCursor();        }    }    /**     * 根据URI匹配 URI_CODE，从而匹配ContentProvIDer中相应的表名     */    public static  final  String gettablename(Uri uri){        String tablename = null;        switch (mMatcher.match(uri)) {            case User_Code:                tablename = DBHelper.USER_table_name;                break;            case Job_Code:                tablename = DBHelper.JOB_table_name;                break;            case AF_Code:                tablename = MyDataBaseHelper.table_USER_AF;                break;        }        return tablename;    }    public voID FinnInsert(Uri uri, ContentValues values) {        //自行封装方法添加数据库        String table = gettablename(uri);        switch (table){//根据表名 插入数据            case MyDataBaseHelper.table_USER_AF://通过KEY获取value                MyDataBase.getInstance(mContext).InsertCaraF(new CarInfo(                        values.get("car_user_az_af").toString(), values.get("car_kfb_name_af").toString(),                        values.get("car_user_cartype_af").toString(), values.get("car_kfb_date_af").toString(),                        values.get("car_kfb_lengmei_af").toString()                ));//                MyDataBase.getInstance(mContext).InsertCaraF(new CarInfo(//                        values.get(MyDataBaseHelper.USER_CAR_AZ_AF).toString(), values.get(MyDataBaseHelper.USER_CAR_name_AF).toString(),//                        values.get(MyDataBaseHelper.USER_CAR_TYPE_AF).toString(), values.get(MyDataBaseHelper.USER_CAR_DATE_AF).toString(),//                        values.get(MyDataBaseHelper.USER_CAR_LENGM_AF).toString()//                ));                break;            default:                break;        }    }    public voID Finnquery(String tablename) {        //自行封装方法添加数据库        switch (tablename){//根据表名 插入数据            case MyDataBaseHelper.table_USER_AF:                mListener.OnReList(MyDataBase.getInstance(mContext).queryListAF());                break;            default:                break;        }    }}

 

 

　第三步：在Manifest中注册provIDer；

<?xml version="1.0" enCoding="utf-8"?><manifest xmlns:androID="http://schemas.androID.com/apk/res/androID"    xmlns:tools="http://schemas.androID.com/tools"    package="com.saiyi.contentprovIDerdemo1">    <application        androID:allowBackup="true"        androID:icon="@mipmap/ic_launcher"        androID:label="@string/app_name"        androID:roundIcon="@mipmap/ic_launcher_round"        androID:supportsRtl="true"        androID:theme="@style/Apptheme"        tools:ignore="GoogleAppIndexingWarning">        <activity androID:name=".MainActivity">            <intent-filter>                <action androID:name="androID.intent.action.MAIN" />                <category androID:name="androID.intent.category.LAUNCHER" />            </intent-filter>        </activity>        <!--authoritIEs地址和 BaseContentProvIDer中的autoHORITY要保持一致-->        <provIDer androID:name=".BaseContentProvIDer"            androID:authoritIEs="Finn.zy.myprovIDer"            androID:enabled="true"            androID:exported="true"            />    </application></manifest>

 

package com.saiyi.contentprovIDerdemo1;

import androID.content.ContentProvIDer;
import androID.content.ContentValues;
import androID.content.Context;
import androID.content.UriMatcher;
import androID.database.Cursor;
import androID.database.sqlite.sqliteDatabase;
import androID.net.Uri;
import androID.util.Log;

/**
 * <pre>
*     author : Finn
 *     e-mail : 892603597@qq.com
 *     time   : 2019/10/14
 *     desc   : https://www.cnblogs.com/finn21/
 * </pre>
*/
public class BaseContentProvIDer extends ContentProvIDer{

    private Context mContext;
DBHelper mDbHelper = null;
sqliteDatabase db = null;
    public static final String autoHORITY = "Finn.zy.myprovIDer";
// 设置ContentProvIDer的唯一标识

public static final int User_Code = 1;
    public static final int Job_Code = 2;
    public static final int AF_Code = 32;
// UriMatcher类使用:在ContentProvIDer 中注册URI
private static final UriMatcher mMatcher;

    public static DataBaseMonitor mListener = null;

    public static voID setDataBaseMonitorListener(DataBaseMonitor Listener) {
        mListener = Listener;
}

    static{
        mMatcher = new UriMatcher(UriMatcher.NO_MATCH);
// 初始化
mMatcher.addURI(autoHORITY,DBHelper.USER_table_name, User_Code); // 若URI资源路径 = "content://" + autoHORITY +"/user"
mMatcher.addURI(autoHORITY, DBHelper.JOB_table_name, Job_Code);// 若URI资源路径 = "content://" + autoHORITY +"/job"
mMatcher.addURI(autoHORITY, MyDataBaseHelper.table_USER_AF, AF_Code);// 若URI资源路径 = "content://" + autoHORITY +"/job"
        // 固定前缀 "content://" + autoHORITY，数据库链表的名称，则返回注册码User_Code
        //固定前缀 "content://" + autoHORITY ，数据库链表的名称，则返回注册码Job_Code
}

    // 以下是ContentProvIDer的6个方法
@OverrIDe
public boolean onCreate() {
        //该方法在ContentProvIDer创建后就会被调用，AndroID开机后，
// ContentProvIDer在其它应用第一次访问它时才会被创建，同时，要讲返回值修改成true。
mContext = getContext();

// 在ContentProvIDer创建时对数据库进行初始化
// 运行在主线程，故不能做耗时 *** 作,此处仅作展示
mDbHelper = new DBHelper(getContext());
db = mDbHelper.getWritableDatabase();

// 初始化两个表的数据(先清空两个表,再各加入一个记录)
db.execsql("delete from user");
db.execsql("insert into user values(1,'Carson');");
db.execsql("insert into user values(2,'Kobe');");

MyDataBase.getInstance(mContext).InsertCaraF(new CarInfo("宝马","奔驰","路虎","宾利","保时捷"));
MyDataBase.getInstance(mContext).InsertCaraF(new CarInfo("宝马1","奔驰2","路虎3","宾利4","保时捷5"));

        return true;
}
    public static final int ITEMS = 1;
    public static final int ITEMS_ID = 2;
//    如果 *** 作的数据属于集合类型，那么MIME类型字符串应该以vnd.androID.cursor.dir/开头。
//    例如：要得到所有person记录的Uri为content://com.cfox.contentprovID.PersonProvIDer/person
//    那么返回的MIME类型字符串应该为："vnd.androID.cursor.dir/person"

    //    如果要 *** 作的数据属于非集合类型数据，那么MIME类型字符串应该以vnd.androID.cursor.item/开头
//    例如：得到ID为10的person记录，Uri为content://com.cfox.contentprovID.PersonProvIDer/person/10
//    那么返回的MIME类型字符串为："vnd.androID.cursor.item/person"
@OverrIDe
public String getType(Uri uri) {
        return null;
}

    @OverrIDe
public Uri insert(Uri uri, ContentValues values) {
        //该方法用于供外部应用往ContentProvIDer添加数据。

// 根据URI匹配 URI_CODE，从而匹配ContentProvIDer中相应的表名
// 该方法在最下面
String table = gettablename(uri);
Log.e("sdfsdf",table+"====="+MyDataBaseHelper.table_USER_AF);
        if(table != null && !MyDataBaseHelper.table_USER_AF.equals(table)){
            // 向该表添加数据
db.insert(table, null, values);
// 当该URI的ContentProvIDer数据发生变化时，通知外界（即访问该ContentProvIDer数据的访问者）
mContext.getContentResolver().notifyChange(uri, null);
            return uri;
}else{
            FinnInsert(uri,values);
            return uri;
}
//        // 通过ContentUris类从URL中获取ID
//        long personID = ContentUris.parseID(uri);
//        System.out.println(personID);

}

    @OverrIDe
public int delete(Uri uri, String selection, String[] selectionArgs) {
        //该方法用于供外部应用从ContentProvIDer删除数据。
String tablename = gettablename(uri);
        if(!MyDataBaseHelper.table_USER_AF.equals(tablename)){
            //使用原生函数的数据库
return 0;
}else{
            //使用封装之后的数据库
return 0;
}
    }

    @OverrIDe
public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {

        return 0;
}
    /**
     * 查询数据
*/
@OverrIDe
public Cursor query(Uri uri, String[] projection, String selection,
String[] selectionArgs, String sortOrder) {
        //该方法用于供外部应用从ContentProvIDer中获取数据。
// 根据URI匹配 URI_CODE，从而匹配ContentProvIDer中相应的表名
// 该方法在最下面
String tablename = gettablename(uri);
Finnquery(tablename);

//        // 通过ContentUris类从URL中获取ID
//        long personID = ContentUris.parseID(uri);
//        System.out.println(personID);
        // 查询数据+
if(!MyDataBaseHelper.table_USER_AF.equals(tablename)){
            //使用原生函数的数据库
return db.query(tablename,projection,selection,selectionArgs,null,null,sortOrder,null);
}else{
            //使用封装之后的数据库
return  MyDataBase.getInstance(mContext).queryCursor();
}
    }



    /**
     * 根据URI匹配 URI_CODE，从而匹配ContentProvIDer中相应的表名
*/
public static  final  String gettablename(Uri uri){
        String tablename = null;
        switch (mMatcher.match(uri)) {
            case User_Code:
                tablename = DBHelper.USER_table_name;
                break;
            case Job_Code:
                tablename = DBHelper.JOB_table_name;
                break;
            case AF_Code:
                tablename = MyDataBaseHelper.table_USER_AF;
                break;
}
        return tablename;
}
    public voID FinnInsert(Uri uri, ContentValues values) {
        //自行封装方法添加数据库
String table = gettablename(uri);
        switch (table){//根据表名 插入数据
case MyDataBaseHelper.table_USER_AF://通过KEY获取value
MyDataBase.getInstance(mContext).InsertCaraF(new CarInfo(
                        values.get("car_user_az_af").toString(), values.get("car_kfb_name_af").toString(),
values.get("car_user_cartype_af").toString(), values.get("car_kfb_date_af").toString(),
values.get("car_kfb_lengmei_af").toString()
                ));
//                MyDataBase.getInstance(mContext).InsertCaraF(new CarInfo(
//                        values.get(MyDataBaseHelper.USER_CAR_AZ_AF).toString(), values.get(MyDataBaseHelper.USER_CAR_name_AF).toString(),
//                        values.get(MyDataBaseHelper.USER_CAR_TYPE_AF).toString(), values.get(MyDataBaseHelper.USER_CAR_DATE_AF).toString(),
//                        values.get(MyDataBaseHelper.USER_CAR_LENGM_AF).toString()
//                ));
break;
            default:
                break;
}
    }

    public voID Finnquery(String tablename) {
        //自行封装方法添加数据库
switch (tablename){//根据表名 插入数据
case MyDataBaseHelper.table_USER_AF:
                mListener.OnReList(MyDataBase.getInstance(mContext).queryListAF());
                break;
            default:
                break;
}
    }

}



总结

以上是内存溢出为你收集整理的Android 数据存储之ContentProvider 使用和应用场景全部内容，希望文章能够帮你解决Android 数据存储之ContentProvider 使用和应用场景所遇到的程序开发问题。

如果觉得内存溢出网站内容还不错，欢迎将内存溢出网站推荐给程序员好友。

欢迎分享，转载请注明来源：内存溢出

原文地址: http://outofmemory.cn/web/1092887.html

赞 (0)
打赏 微信扫一扫 微信扫一扫 支付宝扫一扫 支付宝扫一扫
crsky crsky 一级用户组
0 0
上一篇 2022-05-28
下一篇 2022-05-28

发表评论

登录后才能评论

评论列表（0条）

保存