如何设置默认home Fragment

Question

I've navigation drawer menu with replace content frame, but I don't know how to set a default home fragment.

This is my code

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

    menu = getResources().getStringArray(R.array.menu);
    dLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
    dList = (ListView) findViewById(R.id.left_drawer);
    adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, menu);
    dList.setAdapter(adapter);
    dList.setSelector(R.color.pick);
    dList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> arg0, View v, int position, long id) {
            dLayout.closeDrawers();
            Bundle args = new Bundle();
            args.putString("Menu", menu[position]);
            Fragment detail = null;
            FragmentManager FM = getFragmentManager();
            switch (position) {
                case 0:
                    detail = new HomeFragment();
                    break;
                case 1:
                    detail = new DataBase();
                    break;
                case 2:
                    detail = new MappingFragment();
                    break;
                case 3:
                    detail = new HelpFragment();
                    break;
                default:
                    break;
            }
            FM.beginTransaction().replace(R.id.content_frame, detail).commit();
        }
    });
}

I want set HomeFragment to default chosen/home page

Answer 1

default:
    detail = new HomeFragment();
    break;

The default case is selected when no other cases apply

Answer 2

Thanks for the answer, problem resolved.

    @Override
    protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    menu = getResources().getStringArray(R.array.menu);
    dLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
    dList = (ListView) findViewById(R.id.left_drawer);
    adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, menu);

    Fragment home = new HomeFragment();
    FragmentManager FM = getFragmentManager();
    FM
        .beginTransaction()
        .replace(R.id.content_frame, home)
        .commit();

    dList.setAdapter(adapter);
    dList.setSelector(R.color.pick);
    dList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> arg0, View v, int position, long id) {
            dLayout.closeDrawers();
            Bundle args = new Bundle();
            args.putString("Menu", menu[position]);
            Fragment detail = null;
            FragmentManager FM = getFragmentManager();
            switch (position) {
                case 0:
                    detail = new HomeFragment();
                    break;
                case 1:
                    detail = new DataBase();
                    break;
                case 2:
                    detail = new MappingFragment();
                    break;
                case 3:
                    detail = new HelpFragment();
                    break;
                default:
                    break;
            }
            FM.beginTransaction().replace(R.id.content_frame, detail).commit();
        }
    });
}

Answer 3

在 Main Activity 的 onCreate 方法中添加以下代码：

getFragmentManager().beginTrasaction().replace(r.id.frame_layout, new HomeFragment()).commit();

Answer 4

In the navigation drawer , a better solution would be to add the following code in your onCreate method:

if (savedInstanceState == null) {
    getSupportFragmentManager().beginTransaction().replace(R.id.fragment_container,
            new FRAGMENT_CLASS_NAME_HERE()).commit();
    navigationView.setCheckedItem(R.id.DRAWE_NAV_ITEM_ID_HERE);
}

This is much simpler than many other options and also selected the nav menu item.

Answer 5

Create a setDefaultFragment() method in onCreate() :

private void setDefaultFragment() {
   getSupportFragmentManager().beginTransaction().replace(R.id.fragment_container, new HomeFragment()).commit();
}