自定义ContentProvider的简单增删除改

自定义一个类继承ContentProvider（内容提供者）重新里面的六个方法，通过

getContentResolver()来调用ContentProvider（内容提供者）中的方法

private DbHelper dbHelper;

private SQLiteDatabase sqLiteDatabase;
private UriMatcher uriMatcher;

@Override
public boolean onCreate() {
    Log.i("test","onCreate");
    dbHelper = new DbHelper(getContext(),"person.db",null,2);
    sqLiteDatabase = dbHelper.getReadableDatabase();
    return false;
}

@Nullable
@Override
public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) {
    Log.i("test","query1111");
            return sqLiteDatabase.query(false,"person",projection,selection,selectionArgs,null,null,sortOrder,null);
}

@Nullable
@Override
public String getType(Uri uri) {
    Log.i("test","getType");
    return null;
}

@Nullable
@Override
public Uri insert(Uri uri, ContentValues values) {
    Log.i("test","insert");
    sqLiteDatabase.insert("person","name",values);
    return null;
}

@Override
public int delete(Uri uri, String selection, String[] selectionArgs) {
    Log.i("test","delete");
    sqLiteDatabase.delete("person",selection,selectionArgs);
    return 0;
}

@Override
public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
    Log.i("test","update");
    sqLiteDatabase.update("person",values,selection,selectionArgs);
    return 0;
}

内容访问者：
添加数据

public void add(View view){
    String name=t_main_name.getText().toString();//获取EditText中name的值    
    String age=et_main_age.getText().toString();  //获取EditText中age的值
    uri = Uri.parse("content://com.example.android_16_sqlite.PERSONS");//
    //保存到数据库中
    ContentValues values=new ContentValues();//Map
    values.put("name",name);
    values.put("age",age);
    values.putNull("_id");
    cr.insert(uri,values);
}

查询所有数据
public void getDate(View view){ //查询所有 //协议：content:// uri = Uri. parse( "content://com.example.android_16_sqlite.PERSONS"); //查询数据 cursor = cr.query( uri, null, null, null, null); while ( cursor.moveToNext()){ int pid= cursor.getInt( cursor.getColumnIndex( "_id")); String sname= cursor.getString( cursor.getColumnIndex( "name")); int age= cursor.getInt( cursor.getColumnIndex( "age")); } PersonDate();}
修改数据

public void update(View view){
    String id=editText.getText().toString();
    String name=t_main_name.getText().toString();
    String age=et_main_age.getText().toString();
    uri = Uri.parse("content://com.example.android_16_sqlite.PERSONS");
    //要修改的值保存到数据库中
    ContentValues values=new ContentValues();//Map
    values.put("name",name);
    values.put("age",age);
    cr.update(uri,values,"_id=?",new String[]{id+""});
}

删除数据

public void delete(View view){
    String id=editText.getText().toString();
    uri = Uri.parse("content://com.example.android_16_sqlite.PERSONS");
    cr.delete(uri,"_id=?",new String[]{id+""});
}