自定义ContentProvider

1.自定义Mycontent继承ContentProvider

public class Mycontent extends ContentProvider{    private MySqlite helper;    static UriMatcher matcher=new UriMatcher(UriMatcher.NO_MATCH);    static{        matcher.addURI("com.example.china","fatheradd", 0);        matcher.addURI("com.example.china","fatherdel", 1);        matcher.addURI("com.example.china","fatherup", 2);        matcher.addURI("com.example.china","fathersel", 3);        matcher.addURI("com.example.china","sonadd",4);        matcher.addURI("com.example.china","sondel",5);        matcher.addURI("com.example.china","sonup",6);        matcher.addURI("com.example.china","sonsel",7);    }    @Override    public boolean onCreate() {        helper = new MySqlite(getContext());        helper.getWritableDatabase();        return false;    }    @Override    public Cursor query(Uri uri, String[] projection, String selection,            String[] selectionArgs, String sortOrder) {        SQLiteDatabase db = helper.getWritableDatabase();        Cursor cursor=null;        switch (matcher.match(uri)) {        case 3:            cursor = db.query("father", projection, selection, selectionArgs, null, null, null);            break;        case 7:            cursor = db.query("son", projection, selection, selectionArgs, null, null, null);            break;        default:            break;        }        return cursor;    }    @Override    public String getType(Uri uri) {        // TODO Auto-generated method stub        return null;    }    @Override    public Uri insert(Uri uri, ContentValues values) {        SQLiteDatabase db = helper.getWritableDatabase();        switch (matcher.match(uri)) {        case 0:            db.insert("father",null, values);            break;        case 4:            db.insert("son",null, values);            break;        default:            break;        }        return uri;    }    @Override    public int delete(Uri uri, String selection, String[] selectionArgs) {        SQLiteDatabase db = helper.getWritableDatabase();        switch (matcher.match(uri)) {        case 1:            db.delete("father", selection, selectionArgs);            break;        case 5:            db.delete("son", selection, selectionArgs);            break;        default:            break;        }        return 0;    }    @Override    public int update(Uri uri, ContentValues values, String selection,            String[] selectionArgs) {        return 0;    }

//配置清单文件

<provider android:name="com.example.content123.Mycontent" android:exported="true" android:authorities="com.example.china"> </provider>

//创建数据库兵并初始化几条数据

public class MySqlite extends SQLiteOpenHelper {    public MySqlite(Context context) {        super(context, "shiyou.db", null, 1);    }    @Override    public void onCreate(SQLiteDatabase db) {        db.execSQL("create table father(_id integer primary key autoincrement,name varchar(20),age integer)");        db.execSQL("create table son(_id integer primary key autoincrement,sex varchar(20),phone varchar(11),uid integer,foreign key(uid) references father(_id))");        db.execSQL("insert into father(name,age) values('zhangsan',21)");        db.execSQL("insert into father(name,age) values('lisi',22)");        db.execSQL("insert into father(name,age) values('wangwu',25)");        db.execSQL("insert into son(sex,phone,uid) values('男','131455788',1)");        db.execSQL("insert into son(sex,phone,uid) values('女','111111111',2)");    }    @Override    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {    }

内容提供之创建完毕

通过ContentResolver进行增、删、改、查

public class MainActivity extends Activity implements OnClickListener {

private EditText name;private EditText age;private EditText sex;private EditText num;private Button add;private Button del;private Button up;private Button sel;private ContentResolver contentResolver;private EditText ui;@Overrideprotected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main);    init();    contentResolver = getContentResolver();}// 初始化控件信息private void init() {    name = (EditText) findViewById(R.id.name);    age = (EditText) findViewById(R.id.age);    sex = (EditText) findViewById(R.id.sex);    num = (EditText) findViewById(R.id.num);    ui = (EditText) findViewById(R.id.ui);    add = (Button) findViewById(R.id.add);    del = (Button) findViewById(R.id.del);    up = (Button) findViewById(R.id.up);    sel = (Button) findViewById(R.id.sel);    // 绑定监听    add.setOnClickListener(this);    del.setOnClickListener(this);    up.setOnClickListener(this);    sel.setOnClickListener(this);}@Overridepublic void onClick(View v) {    String uid = ui.getText().toString();    String ename = name.getText().toString();    String eage = age.getText().toString();    String esex = sex.getText().toString();    String pnum = num.getText().toString();    ContentValues values = new ContentValues();    switch (v.getId()) {    case R.id.add:        values.put("sex", esex);        values.put("phone", pnum);        values.put("uid", Integer.parseInt(uid));        contentResolver.insert(                Uri.parse("content://com.example.china/sonadd"), values);        break;    case R.id.del:        contentResolver.delete(                Uri.parse("content://com.example.china/fatherdel"),                "name=?", new String[] { ename });        break;    case R.id.up:        //contentResolver.update("content://com.example.china/sonup", values, where, selectionArgs)        break;    case R.id.sel:        break;    default:        break;    }}

}