Question

我想将Action Bar标题从片段更改为片段..

示例loginfragment to registerfragment ..

我在loginfragment上有一个按钮，它会重定向到注册片段..

case R.id.textSignup:
                FragmentManager fragmentManager = getFragmentManager();
                fragmentManager.beginTransaction()
                        .replace(R.id.container, RegisterFragment.newInstance())
                        .commit();
                break;

我将此代码添加到我的registerfragment

中

public static RegisterFragment newInstance() {
        RegisterFragment fragment = new RegisterFragment();
        return fragment;
    }

    public RegisterFragment () {
    }


    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);
        ((MainActivity) activity).onSectionAttached(3);
    }

然后是MainActivity

 public void onSectionAttached(int number) {
        switch (number) {
            case 1:
                mTitle = getString(R.string.title_home);
                break;
            case 2:
                mTitle = getString(R.string.title_login);
                break;
            case 3:
                mTitle = getString(R.string.title_register);
                break;
        }
    }

    @SuppressWarnings("deprecation")
    public void restoreActionBar() {
        ActionBar actionBar = getSupportActionBar();
        actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_STANDARD);
        actionBar.setDisplayShowTitleEnabled(true);
        actionBar.setTitle(mTitle);
    }

问题是寄存器标题没有显示，即使我在registerfragment中添加了onSectionAttached（3）..

这是MainActivity Code

package com.example.administrator.mosbeau;

import android.app.Activity;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.app.Fragment;
import android.app.FragmentManager;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.support.v4.widget.DrawerLayout;


public class MainActivity extends ActionBarActivity
        implements NavigationDrawerFragment.NavigationDrawerCallbacks {

    /**
     * Fragment managing the behaviors, interactions and presentation of the navigation drawer.
     */
    private NavigationDrawerFragment mNavigationDrawerFragment;

    /**
     * Used to store the last screen title. For use in {@link #restoreActionBar()}.
     */
    private CharSequence mTitle;

    Boolean InternetAvailable = false;
    Seocnd detectconnection;

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

        detectconnection = new Seocnd(this);
        InternetAvailable = detectconnection.InternetConnecting();
        if (InternetAvailable) {
        } else {
            NointernetFragment fragment = new NointernetFragment();
            FragmentManager fragmentManager = getFragmentManager();
            fragmentManager.beginTransaction()
                    .replace(R.id.container, fragment)
                    .commit();
        }

        mNavigationDrawerFragment = (NavigationDrawerFragment)
                getSupportFragmentManager().findFragmentById(R.id.navigation_drawer);
        mTitle = getTitle();

        // Set up the drawer.
        mNavigationDrawerFragment.setUp(
                R.id.navigation_drawer,
                (DrawerLayout) findViewById(R.id.drawer_layout));
    }

    @Override
    public void onNavigationDrawerItemSelected(int position) {

        FragmentManager fragmentManager = getFragmentManager();

        // NEW STUFF
        if(position == 0){
            fragmentManager.beginTransaction()
                    .replace(R.id.container, HomeFragment.newInstance())
                    .commit();
        } else if (position == 1){
            fragmentManager.beginTransaction()
                    .replace(R.id.container, LoginFragment.newInstance())
                    .commit();
        }
    }

    public void onSectionAttached(int number) {
        switch (number) {
            case 1:
                mTitle = getString(R.string.title_home);
                break;
            case 2:
                mTitle = getString(R.string.title_login);
                break;
            case 3:
                mTitle = getString(R.string.title_register);
                break;
        }
    }

    @SuppressWarnings("deprecation")
    public void restoreActionBar() {
        ActionBar actionBar = getSupportActionBar();
        actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_STANDARD);
        actionBar.setDisplayShowTitleEnabled(true);
        actionBar.setTitle(mTitle);
    }



    @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.main, menu);
            restoreActionBar();
            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();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

    /**
     * A placeholder fragment containing a simple view.
     */
    public static class PlaceholderFragment extends Fragment {
        /**
         * The fragment argument representing the section number for this
         * fragment.
         */
        private static final String ARG_SECTION_NUMBER = "section_number";

        /**
         * Returns a new instance of this fragment for the given section
         * number.
         */
        public static PlaceholderFragment newInstance(int sectionNumber) {
            PlaceholderFragment fragment = new PlaceholderFragment();
            Bundle args = new Bundle();
            args.putInt(ARG_SECTION_NUMBER, sectionNumber);
            fragment.setArguments(args);
            return fragment;
        }

        public PlaceholderFragment() {
        }

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                                 Bundle savedInstanceState) {
            View rootView = inflater.inflate(R.layout.fragment_main, container, false);
            return rootView;
        }

        @Override
        public void onAttach(Activity activity) {
            super.onAttach(activity);
            ((MainActivity) activity).onSectionAttached(
                    getArguments().getInt(ARG_SECTION_NUMBER));
        }

    }

}

谢谢

乔

Answer 1

即bcoz你没有在你的代码中的任何地方调用restoreActionBar()函数。

您可以更改操作栏标题，同时在片段之间导航到片段，以及每个片段的onCreateView()。

ActionBar actionBar = getActivity().getActionBar();
        actionBar.setTitle("Your title");

Answer 2

最简单的方法是打电话 getActivity（）。的setTitle（your_title）在所有片段中的onCreate（）方法

如何将Action Bar标题从片段更改为片段？

2 个答案: