从联系人意图添加联系人后如何刷新列表视图？

Question

我有一个活动，我在列表视图中显示来自电话的联系人。现在我添加了通过调用联系人意图添加新联系人来添加新联系人的功能。这做得很好。

但是当我在添加联系人后返回活动时，我看不到最新添加的联系人。

我尝试通过在适配器上调用 invalidate() 来刷新列表视图，我尝试通过调用 invalidate() onResume 方法。

但我无法得到结果。我还尝试使用 startActivityForResult 调用添加意图并在 onActivityResult() 中获取联系人，但这也失败了。

不知道怎么回事。请帮忙。

活动：

public class ContactList extends AppCompatActivity {


    private ArrayList<contact> contact_list = null;
    private contactAdapter mContactAdapter = null;

    private ArrayList<contact> items;
    private ArrayList<contact> selectedContacts;
    boolean[] isChecked;
    Cursor mCursor;
    ListView lv;
    public int RQS_PICK_CONTACT = 1,RQS_ADD_CONTACT = 2;
    private static final int PERMISSIONS_REQUEST_READ_CONTACTS = 100;
    ArrayList<Integer> selectedItemsPositions;
    private ImageView done,back;
    private boolean mContactListActivity;
    private FloatingActionButton fab;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_contacts_list);

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

        toolbar.setTitle("");
        TextView toolbarTitle = (TextView) toolbar.findViewById(R.id.toolbar_title);

        toolbarTitle.setText("Select Contacts");

        setSupportActionBar(toolbar);

        done = (ImageView)findViewById(R.id.done);

        back = (ImageView)findViewById(R.id.back);

        fab = (FloatingActionButton)findViewById(R.id.fab);

        contact_list = new ArrayList<contact>();

        selectedContacts = new ArrayList<contact>();

     //   selectedItemsPositions = new ArrayList<>();

        lv = (ListView)findViewById(R.id.list);

        showContacts();

        //getContacts();


        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {


                Intent intent = new Intent(Intent.ACTION_INSERT,
                        ContactsContract.Contacts.CONTENT_URI);
                startActivityForResult(intent,RQS_ADD_CONTACT);


            }
        });


    }

    @SuppressWarnings("unused")
    private void getContacts() {


        String[] projection = new String[] {
                ContactsContract.Contacts.DISPLAY_NAME,
                ContactsContract.Contacts.HAS_PHONE_NUMBER,
                ContactsContract.Contacts._ID };


       mCursor = managedQuery(ContactsContract.Contacts.CONTENT_URI, null, null, null, "upper("+ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME + ") ASC");

        while (mCursor.moveToNext()) {
            contact contact = new contact();

            String contactId = mCursor.getString(mCursor.getColumnIndex(ContactsContract.Contacts._ID));

            contact.setContactid(mCursor.getString(mCursor.getColumnIndex(ContactsContract.Contacts._ID)));
            contact.setContactName(mCursor.getString(mCursor.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME)));
            contact_list.add(contact);
        }
        isChecked = new boolean[mCursor.getCount()];

        for (int i = 0; i < isChecked.length; i++) {
            isChecked[i] = false;
        }


        this.mContactAdapter = new contactAdapter(this, R.layout.contact_list_item, contact_list);
        lv.setAdapter(this.mContactAdapter);
        mContactAdapter.notifyDataSetChanged();
     //   mCursor.close();

    }


    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        // TODO Auto-generated method stub
        super.onActivityResult(requestCode, resultCode, data);

        if (requestCode == RQS_PICK_CONTACT) {
            if (resultCode == RESULT_OK) {

                getContacts();

            }
        }

    }


    @Override
    public void onRequestPermissionsResult(int requestCode, String[] permissions,
                                           int[] grantResults) {
        if (requestCode == PERMISSIONS_REQUEST_READ_CONTACTS) {
            if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                // Permission is granted
                getContacts();
            } else {
                Toast.makeText(this, "Until you grant the permission, we canot display the names", Toast.LENGTH_SHORT).show();
            }
        }
    }


    private void showContacts()
    {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M && checkSelfPermission(Manifest.permission.READ_CONTACTS) != PackageManager.PERMISSION_GRANTED) {

            requestPermissions(new String[]{Manifest.permission.READ_CONTACTS}, PERMISSIONS_REQUEST_READ_CONTACTS);
            //After this point you wait for callback in onRequestPermissionsResult(int, String[], int[]) overriden method
        }

        else {

            getContacts();

        }

    }

    @Override
    public void onResume()
    {

        super.onResume();

        mContactAdapter.notifyDataSetInvalidated();

        //Intent intent = getIntent();
        //intent.addFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION);
        //finish();
        //startActivity(intent);

    }

}

Answer 1

试试这个：

    inside yourr onResume() add this
   if (listvew!= null) {
    listvew.invalidateViews();
}
 adapter.notifyDataSetChanged();

Answer 2

在onResume()里面添加这个

if(adapter!= null){
    listvew.setAdapter(adapter);
    adapter.notifyDataSetChanged();
}