Question

我在MainActivity中实现了NavigationView。 MainActivity包含Fragment容器。默认HomeFragment位于此容器内。然后我在这个容器中添加另一个Fragment（SecondFragment）。现在汉堡包图标应该更改为返回导航图标（后退箭头图标），单击此图标应该转到上一个片段。但现在单击主页按钮（后退箭头图标）将打开导航抽屉。这是我的MainActivity` 公共类MainActivity扩展了AppCompatActivity {

private Toolbar toolbar;
private NavigationView navigationView;
private DrawerLayout drawerLayout;
ActionBarDrawerToggle actionBarDrawerToggle;

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

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


    navigationView = (NavigationView) findViewById(R.id.navigation_view);


    navigationView.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() {


        @Override
        public boolean onNavigationItemSelected(MenuItem menuItem) {


            if (menuItem.isChecked()) menuItem.setChecked(false);
            else menuItem.setChecked(true);

            drawerLayout.closeDrawers();


            switch (menuItem.getItemId()) {




                default:
                    Toast.makeText(getApplicationContext(), "Nothing", Toast.LENGTH_SHORT).show();
                    return true;

            }
        }
    });


    drawerLayout = (DrawerLayout) findViewById(R.id.drawer);
    actionBarDrawerToggle = new ActionBarDrawerToggle(this, drawerLayout,toolbar, R.string.openDrawer, R.string.closeDrawer) {

        @Override
        public void onDrawerClosed(View drawerView) {

            super.onDrawerClosed(drawerView);
        }

        @Override
        public void onDrawerOpened(View drawerView) {


            super.onDrawerOpened(drawerView);
        }
    };

    drawerLayout.setDrawerListener(actionBarDrawerToggle);


    actionBarDrawerToggle.syncState();


}

@Override
public boolean onCreateOptionsMenu(Menu menu) {

    getMenuInflater().inflate(R.menu.menu_main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {

    int id = item.getItemId();


    if (id == R.id.action_settings) {
        return true;
    }
    if (id == android.R.id.home) {

        return false;
    }
    return super.onOptionsItemSelected(item);
}}

`

这是我的SecondFragment代码` 公共类SecondFragment扩展Fragment { TextView收件箱;

@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View v = inflater.inflate(R.layout.second_fragment, container, false);
    ((AppCompatActivity) getActivity()).getSupportActionBar().setDisplayHomeAsUpEnabled(true);
    setHasOptionsMenu(true);
    return v;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {

    int id = item.getItemId();

    if (id == android.R.id.home) {
        Log.e("backIcon", "backIcon");
        return true;
    }

    return super.onOptionsItemSelected(item);
}}

`

Answer 1

您可以使用KeyCode处理：

@Override
public void onResume() {

    super.onResume();

    getView().setFocusableInTouchMode(true);
    getView().requestFocus();
    getView().setOnKeyListener(new View.OnKeyListener() {
        @Override
        public boolean onKey(View v, int keyCode, KeyEvent event) {

            if (event.getAction() == KeyEvent.ACTION_UP && keyCode == KeyEvent.KEYCODE_BACK){

                // handle back button

                return true;

            }

            return false;
        }
    });
}

OR

您需要获取onOptionsItemSelected项的ID。所以根据你可以决定回来。

如何在片段中处理NavigationView后退图标？

1 个答案: