Question

我想在我的应用程序中完成一项任务，该任务是使用我创建的B从我的sqlite数据库中获取项目ID，并且这次我想使用在活动中获取的ID（不是适配器，而是我）知道如何从适配器执行此操作。虽然我是第一次尝试，但我什至不知道是否可能。

这是我尝试过的代码

Model.class

 private ViewPager mViewPager;
ArrayList<Model> modelArrayList;
ArrayList<String>listItem;

RecyclerView recyclerView;
SongAdapter adapter;
int id = 0;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);

    listItem = new ArrayList<>();

    SQLiteDbHelper dbHelper = new SQLiteDbHelper(this);
    dbHelper.openDatabase();
    modelArrayList  = dbHelper.getDetails();

    adapter = new SongAdapter(modelArrayList);

    recyclerView = (RecyclerView) findViewById(R.id.recycler_view);
    recyclerView.setLayoutManager(new LinearLayoutManager(this));
    recyclerView.setAdapter(adapter);

}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    MenuInflater inflater = getMenuInflater();
    inflater.inflate(R.menu.menu_main,menu);

    return super.onCreateOptionsMenu(menu);
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {

    if (item.getItemId() == R.id.action_search){
        Intent intent = new Intent(MainActivity.this,SearchActivity.class);
        startActivity(intent);
    }

    if (item.getItemId() == R.id.lacate){
        goToChapter();
    }

    if (item.getItemId() == R.id.locate){
        Intent intent = new Intent(MainActivity.this,ChaptersActivity.class);
        startActivity(intent);

    }

    return super.onOptionsItemSelected(item);
}

private void goToChapter() {
    AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this,R.style.AlertDialog);
    builder.setTitle("Enter Here :");

    final EditText goTo = new EditText(MainActivity.this);
    goTo.setHint("input number");
    builder.setView(goTo);

    builder.setPositiveButton("GO", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialogInterface, int i) {
            String locate = goTo.getText().toString();

            if (!TextUtils.isEmpty(locate) ){
                if (!locate.equals(String.valueOf(modelArrayList.get(id).getChapter()))) {
                    Toast.makeText(MainActivity.this,"bad",Toast.LENGTH_LONG).show();

                } else {

                    Toast.makeText(MainActivity.this,"good",Toast.LENGTH_LONG).show();

                }
            }
        }
    });
    builder.show();

}

但是id仅注册为零，并且不会从数据库中检索任何内容

从android中的活动访问`Model.class`中的数据

0 个答案: