Question

我正在读取电话联系人并将其存储到SQLite表中，但它的工作正常，但是当我试图显示来自SQLite表的同一活动中的联系人进入列表视图时，我需要关闭并重新打开活动以查看来自SQLite的联系人列表表格。我该怎么做，请提供解决方案。谢谢。

public class ContactsActivity extends AppCompatActivity {
    private DataBaseHelper db;
    private ListView listView;
    private ProgressBar progressBar;
    private List<String> namelist=null;
    private Button btnLoad;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_contacts);
        listView = findViewById(R.id.listView);
        progressBar = findViewById(R.id.progressBar);
        btnLoad = findViewById(R.id.btnLoad);
        db=new DataBaseHelper(ContactsActivity.this);
        namelist = db.getData();

        if(namelist.size()>0)
        {
            ArrayAdapter listadapter = new ArrayAdapter<>(getApplication(),android.R.layout.simple_list_item_1,namelist);
            listView.setAdapter(listadapter);
        }
        else{
            AsyncTask.execute(() -> getcontacts());

        }

    }
    public void getcontacts()
    {
            progressBar.setVisibility(View.VISIBLE);
            db=new DataBaseHelper(ContactsActivity.this);
            ContentResolver cr = getContentResolver();
            Cursor cur = cr.query(ContactsContract.Contacts.CONTENT_URI,
                    null, null, null, null);
            assert cur != null;
            if (cur.getCount() > 0) {
                while (cur.moveToNext()) {
                    String id = cur.getString(cur.getColumnIndex(ContactsContract.Contacts._ID));
                    if (Integer.parseInt(cur.getString(
                            cur.getColumnIndex(ContactsContract.Contacts.HAS_PHONE_NUMBER))) > 0) {
                        Cursor pCur = cr.query(
                                ContactsContract.CommonDataKinds.Phone.CONTENT_URI,
                                null,
                                ContactsContract.CommonDataKinds.Phone.CONTACT_ID +" = ?",
                                new String[]{id}, null);
                        assert pCur != null;
                        while (pCur.moveToNext()) {
                            String phoneNo = pCur.getString(pCur.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER));
                            String Name = pCur.getString(pCur.getColumnIndex(ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME));
                            db.insert(Name,phoneNo);

                        }
                        pCur.close();
                    }
                }
                progressBar.setVisibility(View.GONE);

                        namelist = db.getData();
                        ArrayAdapter listadapter = new ArrayAdapter<>(getApplication(),android.R.layout.simple_list_item_1,namelist);
                        listadapter.notifyDataSetChanged();
                        listView.setAdapter(listadapter);


                cur.close();
            }
    }

}

数据已成功插入到SQLite表中，但是关闭并重新打开活动后，列表视图中正在填充结果。如何在不关闭并重新打开活动的情况下填充结果？

Answer 1

请更改，

ArrayAdapter listadapter = new ArrayAdapter<>(getApplication(),android.R.layout.simple_list_item_1,namelist);
                    listadapter.notifyDataSetChanged();
                    listView.setAdapter(listadapter);

带有以下代码，

ArrayAdapter listadapter = new ArrayAdapter<>(getApplication(),android.R.layout.simple_list_item_1,namelist);
                    listView.setAdapter(listadapter);
                    listadapter.notifyDataSetChanged();

将SQLite表数据显示到列表视图中将数据插入到同一Activity上的表中之后，无需关闭活动并重新打开

1 个答案: