当我切换新活动时，操作栏消失（Android Studio）

Question

Here is my MainActivity

 package com.arrival.grontha;

import android.app.Fragment;
import android.content.Intent;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;

import com.parse.Parse;
import com.parse.ParseAnalytics;
import com.parse.ParseInstallation;
import com.parse.PushService;

public class MainActivity extends ActionBarActivity
        implements NavigationDrawerCallbacks {

    /**
     * Fragment managing the behaviors, interactions and presentation of the navigation drawer.
     */

    private NavigationDrawerFragment mNavigationDrawerFragment;
    private Toolbar mToolbar;

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

        mToolbar = (Toolbar) findViewById(R.id.tool_bar);
        setSupportActionBar(mToolbar);

        //Parse push notification
        Parse.initialize(this, getString(R.string.parse_application_id), getString(R.string.parse_client_key));
        ParseAnalytics.trackAppOpened(getIntent());
        PushService.setDefaultPushCallback(this, MainActivity.class);
        ParseInstallation.getCurrentInstallation().saveInBackground();

        mNavigationDrawerFragment = (NavigationDrawerFragment)
                getFragmentManager().findFragmentById(R.id.fragment_drawer);

        // Set up the drawer.
        mNavigationDrawerFragment.setup(R.id.fragment_drawer, (DrawerLayout) findViewById(R.id.drawer), mToolbar);
        // populate the navigation drawer
        mNavigationDrawerFragment.setUserData(getResources().getString(R.string.app_name), getResources().getString(R.string.email), BitmapFactory.decodeResource(getResources(), R.drawable.ic_logo_app));
    }

    @Override
    public void onNavigationDrawerItemSelected(int position) {
        Fragment fragment;
        switch (position) {
            case 0: //stats
                fragment = getFragmentManager().findFragmentByTag(Fragment_Books.TAG);
                if (fragment == null) {
                    fragment = new Fragment_Books();
                }
                getFragmentManager().beginTransaction().replace(R.id.container, fragment, Fragment_Books.TAG).commit();
                break;
            case 1:
                fragment = getFragmentManager().findFragmentByTag(Fragment_Favorite.TAG);
                if (fragment == null) {
                    fragment = new Fragment_Favorite();
                }
                getFragmentManager().beginTransaction().replace(R.id.container, fragment, Fragment_Favorite.TAG).commit();
                break;
            case 2:
                fragment = getFragmentManager().findFragmentByTag(Fragment_About.TAG);
                if (fragment == null) {
                    fragment = new Fragment_About();
                }
                getFragmentManager().beginTransaction().replace(R.id.container, fragment, Fragment_About.TAG).commit();
                break;
        }
    }


    @Override
    public void onBackPressed() {
        if (mNavigationDrawerFragment.isDrawerOpen())
            mNavigationDrawerFragment.closeDrawer();
        else
            super.onBackPressed();
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        if (!mNavigationDrawerFragment.isDrawerOpen()) {
            // Only show items in the action bar relevant to this screen
            // if the drawer is not showing. Otherwise, let the drawer
            // decide what to show in the action bar.
            getMenuInflater().inflate(R.menu.unused, menu);
            return true;
        }
        return super.onCreateOptionsMenu(menu);
    }


    @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(id) {
            case R.id.menu_settings:
                Intent intent = new Intent(this, SettingsActivity.class);
                startActivity(intent);
        }

        return super.onOptionsItemSelected(item);
    }



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

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

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

}

And Here is My SettingsActivity

    package com.arrival.grontha;

import android.app.ActionBar;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;

public class SettingsActivity extends ActionBarActivity {

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

    }
}

I try to to Switch the SettingsActivity using a ActionBar Menu. It work, but when the SettingsActivity appear my ActionBar goes Disappear :( How can i solve it? Please Help me....

Answer 1

I had the same thing happen. I'm using AndroidStudio 2.3 and created a new activity. The IDE added android:theme="@style/AppTheme.NoActionBar" to the AndroidManifest.xml while creating the new activity.

Answer 2

You need to call setSupportActionBar(yourToolbar) to display the Toolbar. Also, make sure that your activity_settings.xml has a Toolbar defined in it.

Answer 3

我不小心扩展了Activity而不是AppCompatActivity ，默认情况下会包含工具栏。