领域数据不保存java

Question

在调用对话框后，我试图将数据保存到RealmList。该对话框应该采用新对象的名称FixtureInfo，将其添加到RealmList，然后移至下一个活动。然而，在移动到下一个活动并按下后退按钮后，填充有 RealmList 的 ListView 不会显示刚刚创建的对象。没有错误，只是没有出现。有什么想法吗？

EDIT 在 RealmBaseAdapter 中添加，因为 beeeneder 建议我这样做，但问题仍然存在。

第一个活动

public class RoomDescription extends ActionBarActivity {

    public AlertDialog.Builder dialogBuilder;
    public RealmList<FixtureInfo> myFixtures = new RealmList<>();
    public String RoomName;
    public String FixtureName;
    public RealmList<Rooms> myRooms = new RealmList<>();
    private Realm realm;
    public Rooms rooms;

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

        //get room name
        TextView textFixture = (TextView) findViewById(R.id.RoomName);
        Bundle extras = getIntent().getExtras();
        if (extras != null) {
            RoomName = extras.getString("txtString");
            textFixture.setText(RoomName);
        }


        //initiate realm instant to get CompanyInfo object, Room object, and populate myRoom and myFixtures
        realm = Realm.getInstance(this);
        rooms = realm.where(Rooms.class).equalTo("Name", RoomName).findFirst();
        realm.beginTransaction();
        CompanyInfo companyinfo = realm.where(CompanyInfo.class).findFirst();
        myRooms = companyinfo.getRooms();
        myFixtures = rooms.getFixtureInfos();
        realm.commitTransaction();
        populateListView();
    }

    @Override
    protected void onResume() {
        super.onResume();
        LoadInfo();
    }

    @Override
    protected void onPause() {
        super.onPause();
        SaveInfo();
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        realm.close();
    }

    private void setFixtureName()
    {
        //dialog to add fixture to room and set its name
        dialogBuilder = new AlertDialog.Builder(this);
        final EditText txtInput = new EditText(this);


        dialogBuilder.setTitle("New Fixture");
        dialogBuilder.setMessage("What is the fixture name?");
        dialogBuilder.setView(txtInput);
        dialogBuilder.setPositiveButton("Add", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                //initiate realm instant
                Realm realm = Realm.getInstance(getApplicationContext());
                realm.beginTransaction();
                //get fixture name and create FixtureInfo object
                FixtureName = txtInput.getText().toString();
                FixtureInfo fixtureInfo = realm.createObject(FixtureInfo.class);
                fixtureInfo.setName(FixtureName);
                fixtureInfo.setRoomName(RoomName);
                myFixtures.add(fixtureInfo);
                realm.commitTransaction();
                //save changes
                SaveInfo();
                //start new activity
                Intent i = new Intent(RoomDescription.this, FixtureDescription.class);
                i.putExtra("textString", FixtureName);
                i.putExtra("txtString", RoomName);
                populateListView();
                Toast.makeText(getApplicationContext(), "Fixture has been added.", Toast.LENGTH_SHORT).show();
                startActivity(i);

            }
        });
        dialogBuilder.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                SaveInfo();
            }
        });

        AlertDialog dialogFixtureName = dialogBuilder.create();
        dialogFixtureName.show();
    }

    private void setRoomName()
    {
        //same as setRoomName in RoomList.java
        dialogBuilder = new AlertDialog.Builder(this);
        final EditText txtInput = new EditText(this);


        dialogBuilder.setTitle("New Room");
        dialogBuilder.setMessage("What is the room name?");
        dialogBuilder.setView(txtInput);
        dialogBuilder.setPositiveButton("Add", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                Realm realm = Realm.getInstance(getApplicationContext());
                realm.beginTransaction();
                String txtString = txtInput.getText().toString();
                Rooms rooms = realm.createObject(Rooms.class);
                rooms.setName(txtString);
                myRooms.add(rooms);
                realm.commitTransaction();
                SaveInfo();
                realm.close();
                Intent i = new Intent(RoomDescription.this, RoomDescription.class);
                i.putExtra("txtString", txtString);
                Toast.makeText(getApplicationContext(), "Room has been added.", Toast.LENGTH_SHORT).show();
                populateListView();
                startActivity(i);
            }
        });
        dialogBuilder.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                SaveInfo();
            }
        });

        AlertDialog dialogFixtureName = dialogBuilder.create();
        dialogFixtureName.show();
    }

    private void removeFixture()
    {
        //remove fixture from room
        dialogBuilder = new AlertDialog.Builder(this);

        dialogBuilder.setTitle("Select Fixture to Remove");
        dialogBuilder.setSingleChoiceItems(myFixtures.toArray(new String[myFixtures.size()]), -1, new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                //initiate realm instant
                Realm realm = Realm.getInstance(getApplicationContext());
                //remove fixture info from room
                realm.beginTransaction();
                myFixtures = rooms.getFixtureInfos();
                myFixtures.remove(which);
                //save change
                SaveInfo();
                populateListView();
                Toast.makeText(getApplicationContext(), "Fixture has been removed.", Toast.LENGTH_SHORT).show();
                dialog.dismiss();
            }
        });

        AlertDialog dialogFixtureName = dialogBuilder.create();
        dialogFixtureName.show();
    }
    private void populateListView()
    {
        //on click for the list of FixtureInfo connected to the room
        ListView list = (ListView) findViewById(R.id.FixtureList);
        RealmResults<FixtureInfo> results = realm.where(FixtureInfo.class).equalTo("RoomName", RoomName).findAll();
        FixtureListAdapter adapter = new FixtureListAdapter(this, results, true);
        list.setAdapter(adapter);
        list.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                switch (position) {
                    default:
                        Intent i = new Intent(RoomDescription.this, FixtureDescription.class);
                        TextView textItem = (TextView) view;
                        String FixtureName = textItem.getText().toString();
                        i.putExtra("textString", FixtureName);
                        i.putExtra("txtString", RoomName);
                        startActivity(i);
                        break;
                }

            }

        });

    }

    public void SaveInfo()
    {
        //save info or update info
        realm.beginTransaction();
        rooms.setName(RoomName);
        rooms.setFixtureInfos(myFixtures);
        realm.copyToRealmOrUpdate(rooms);
        realm.commitTransaction();
    }

    public void LoadInfo()
    {
        //load info from specific room
        realm.beginTransaction();
        myFixtures = rooms.getFixtureInfos();
        realm.commitTransaction();
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_room_description, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        switch (item.getItemId())
        {
            case R.id.newFixture:
                setFixtureName();
                break;
            case R.id.removeFixture:
                removeFixture();
                break;
            case R.id.add:
                setRoomName();
                break;
            case R.id.home:
                startActivity(new Intent(getApplicationContext(), MainPage.class));
                break;
            case R.id.summary:
                startActivity(new Intent(getApplicationContext(), Summary.class));
                break;
        }


        return super.onOptionsItemSelected(item);
    }
}

RealmBaseAdapter 类

public class FixtureListAdapter extends RealmBaseAdapter<FixtureInfo> implements ListAdapter {
    private static class ViewHolder{
        TextView FixtureName;
    }
    public FixtureListAdapter(Context context, RealmResults<FixtureInfo> realmResults, boolean automaticUpdate) {
        super(context, realmResults, automaticUpdate);
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder viewHolder;
        if (convertView == null) {
            convertView = inflater.inflate(android.R.layout.simple_list_item_1,
                    parent, false);
            viewHolder = new ViewHolder();
            viewHolder.FixtureName = (TextView) convertView.findViewById(android.R.id.text1);
            convertView.setTag(viewHolder);
        } else {
            viewHolder = (ViewHolder) convertView.getTag();
        }

        FixtureInfo fixtureInfo = realmResults.get(position);
        viewHolder.FixtureName.setText(fixtureInfo.getName());
        return convertView;
    }
}

FixtureInfo 类

public class FixtureInfo extends RealmObject{
    @PrimaryKey
    private String RoomName;
    @Ignore
    private String Name;
    private String Description;
    private String Wattage;
    private String Run_Time;
    private String Bulbs_Out;
    private String Notes;
    private int Count;

    public String getRoomName() {
        return RoomName;
    }

    public void setRoomName(String roomName) {
        RoomName = roomName;
    }
    public void setCount(int count) {
        Count = count;
    }

    public int getCount() {
        return Count;
    }

    public void setName(String name) {
        Name = name;
    }

    public void setDescription(String description) {
        Description = description;
    }

    public void setWattage(String wattage) {
        Wattage = wattage;
    }

    public void setRun_Time(String run_Time) {
        Run_Time = run_Time;
    }

    public void setBulbs_Out(String bulbs_Out) {
        Bulbs_Out = bulbs_Out;
    }

    public void setNotes(String notes) {
        Notes = notes;
    }

    public String getName() {
        return Name;
    }

    public String getDescription() {
        return Description;
    }

    public String getWattage() {
        return Wattage;
    }

    public String getRun_Time() {
        return Run_Time;
    }

    public String getBulbs_Out() {
        return Bulbs_Out;
    }

    public String getNotes() {
        return Notes;
    }

}

Answer 1

我建议您在onClick 中设置一个中断指针，以检查您尝试添加的fixtureInfo。因为RoomName 是主键，所以如果你想用不同的RoomName 更改FixtrueInfo，我不希望你会看到ListView 的任何变化，因为RealmResults 是根据原名。

还有其他几个问题：

1. 事务只需要写，不需要读。
2. 如果对象是Realm.createObject创建的，就不用再调用copyToRealmOrUpdate了

我建议您多花几分钟时间了解我们的示例 http://github.com/realm/realm-java/tree/master/examples 。此外，realm-java 背后的机制是我们使用 Proxy 对象来重载 getter/setter。这并不难。您可以在构建目录中找到FixtureInfoRealmProxy.java。理解整个事情会很有趣也很有帮助，也许你也可以快速浏览一下:)