4.4.1 ContentProvider初探

//依次是姓名，号码，邮编 ContentProviderOperation op2 = ContentProviderOperation.newInsert(dataUri) .withValueBackReference("raw_contact_id", 0) .withValue("mimetype", "vnd.android.cursor.item/name") .withValue("data2", "Coder-pig") .build(); operations.add(op2); ContentProviderOperation op3 = ContentProviderOperation.newInsert(dataUri) .withValueBackReference("raw_contact_id", 0) .withValue("mimetype", "vnd.android.cursor.item/phone_v2") .withValue("data1", "13798988888") .withValue("data2", "2") .build(); operations.add(op3); ContentProviderOperation op4 = ContentProviderOperation.newInsert(dataUri) .withValueBackReference("raw_contact_id", 0) .withValue("mimetype", "vnd.android.cursor.item/email_v2") .withValue("data1", "779878443@qq.com") .withValue("data2", "2") .build(); operations.add(op4); //将上述内容添加到手机联系人中~ resolver.applyBatch("com.android.contacts", operations); Toast.makeText(getApplicationContext(), "添加成功", Toast.LENGTH_SHORT).show();}运行结果:别忘了权限：<uses-permission android:name="android.permission.WRITE_CONTACTS"/><uses-permission android:name="android.permission.WRITE_PROFILE"/>3.自定义ContentProvider我们很少会自己来定义ContentProvider，因为我们很多时候都不希望自己应用的数据暴露给其他应用，虽然这样，学习如何ContentProvider还是有必要的，多一种数据传输的方式，是吧~这是之前画的一个流程图：接下来我们就来一步步实现：在开始之前我们先要创建一个数据库创建类(数据库内容后面会讲~)：DBOpenHelper.javapublic class DBOpenHelper extends SQLiteOpenHelper { final String CREATE_SQL = "CREATE TABLE test(_id INTEGER PRIMARY KEY AUTOINCREMENT,name)"; public DBOpenHelper(Context context, String name, CursorFactory factory, int version) { super(context, name, null, 1); } @Override public void onCreate(SQLiteDatabase db) { db.execSQL(CREATE_SQL); } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { // TODO Auto-generated method stub }}Step 1：自定义ContentProvider类，实现onCreate()，getType()，根据需求重写对应的增删改查方法：NameContentProvider.javapublic class NameContentProvider extends ContentProvider { //初始化一些常量 private static UriMatcher matcher = new UriMatcher(UriMatcher.NO_MATCH); private DBOpenHelper dbOpenHelper; //为了方便直接使用UriMatcher,这里addURI,下面再调用Matcher进行匹配 static{ matcher.addURI("com.jay.example.providers.myprovider", "test", 1); } @Override public boolean onCreate() { dbOpenHelper = new DBOpenHelper(this.getContext(), "test.db", null, 1); return true; } @Override public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) { return null; } @Override public String getType(Uri uri) { return null; } @Override public Uri insert(Uri uri, ContentValues values) { switch(matcher.match(uri)) { //把数据库打开放到里面是想证明uri匹配完成 case 1: SQLiteDatabase db = dbOpenHelper.getReadableDatabase(); long rowId = db.insert("test", null, values); if(rowId > 0) { //在前面已有的Uri后面追加ID Uri nameUri = ContentUris.withAppendedId(uri, rowId); //通知数据已经发生改变 getContext().getContentResolver().notifyChange(nameUri, null); return nameUri; } } return null; } @Override public int delete(Uri uri, String selection, String[] selectionArgs) { return 0; } @Override public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) { return 0; }}Step 2：AndroidManifest.xml中为ContentProvider进行注册：<!--属性依次为：全限定类名,用于匹配的URI,是否共享数据 --><provider android:name="com.jay.example.bean.NameContentProvider" android:authorities="com.jay.example.providers.myprovider" android:exported="true" />好的，作为ContentProvider的部分就完成了！接下来，创建一个新的项目，我们来实现ContentResolver的部分，我们直接通过按钮点击插入一条数据：MainActivity.javapublic class MainActivity extends Activity { private Button btninsert; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); btninsert = (Button) findViewById(R.id.btninsert); //读取contentprovider 数据 final ContentResolver resolver = this.getContentResolver(); btninsert.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { ContentValues values = new ContentValues();