Android 我们可以把导航菜单和活动一起使用而不是片段吗?

Android 我们可以把导航菜单和活动一起使用而不是片段吗?,android,android-fragments,Android,Android Fragments,我想完成导航菜单 对我来说,这是我开始学习安卓系统时的第一个问题。但是,嘿,我会试着向你解释为什么每个人都使用碎片: 使用侧菜单更容易管理片段。为什么?因为如果您要将每个菜单项实现为活动,则需要在每个活动中从菜单中实现该“菜单部分”。菜单绑定到Activity,而Fragment只是其中的一部分-您可以向Activity添加Fragment,只需在layout.xml中查看即可 为什么你只需要活动?片段具有getActivity()方法,该方法将返回父级Activity。您可以在片段的onCre

我想完成导航菜单

对我来说,这是我开始学习安卓系统时的第一个问题。但是,嘿,我会试着向你解释为什么每个人都使用碎片:

  • 使用侧菜单更容易管理片段。为什么?因为如果您要将每个菜单项实现为
    活动
    ,则需要在每个
    活动
    中从菜单中实现该“菜单部分”。菜单绑定到
    Activity
    ,而
    Fragment
    只是其中的一部分-您可以向
    Activity
    添加Fragment,只需在layout.xml中查看即可

  • 为什么你只需要活动?片段具有
    getActivity()
    方法,该方法将返回父级
    Activity
    。您可以在片段的
    onCreateView(…)
    方法上实现自己的片段布局。通常,您可以在Activity中实现某种公共方法,然后调用
    ((MyActivity)getActivity())。[your_method_name]()
    来实际调用Activity方法

  • 困难是学习的一部分,所以不要害怕学习新的东西。如果90%的人使用碎片,那么也许使用碎片是有意义的,想想看;)

  • BaseActivity.java

    public class BaseActivity extends ActionBarActivity {
    private DrawerLayout mDrawerLayout;
    private ListView mDrawerList;
    private ActionBarDrawerToggle mDrawerToggle;
    protected RelativeLayout _completeLayout, _activityLayout;
    // nav drawer title
    private CharSequence mDrawerTitle;
    
    // used to store app title
    private CharSequence mTitle;
    
    private ArrayList<NavDrawerItem> navDrawerItems;
    private NavDrawerListAdapter adapter;
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.drawer);
        // if (savedInstanceState == null) {
        // // on first time display view for first nav item
        // // displayView(0);
        // }
    }
    
    public void set(String[] navMenuTitles, TypedArray navMenuIcons) {
        mTitle = mDrawerTitle = getTitle();
    
        mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
        mDrawerList = (ListView) findViewById(R.id.left_drawer);
    
        navDrawerItems = new ArrayList<NavDrawerItem>();
    
        // adding nav drawer items
        if (navMenuIcons == null) {
            for (int i = 0; i < navMenuTitles.length; i++) {
                navDrawerItems.add(new NavDrawerItem(navMenuTitles[i]));
            }
        } else {
            for (int i = 0; i < navMenuTitles.length; i++) {
                navDrawerItems.add(new NavDrawerItem(navMenuTitles[i],
                        navMenuIcons.getResourceId(i, -1)));
            }
        }
    
        mDrawerList.setOnItemClickListener(new SlideMenuClickListener());
    
        // setting the nav drawer list adapter
        adapter = new NavDrawerListAdapter(getApplicationContext(),
                navDrawerItems);
        mDrawerList.setAdapter(adapter);
    
        // enabling action bar app icon and behaving it as toggle button
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
        getSupportActionBar().setHomeButtonEnabled(true);
        // getSupportActionBar().setIcon(R.drawable.ic_drawer);
    
        mDrawerToggle = new ActionBarDrawerToggle(this, mDrawerLayout,
                R.drawable.ic_drawer, // nav menu toggle icon
                R.string.app_name, // nav drawer open - description for
                // accessibility
                R.string.app_name // nav drawer close - description for
        // accessibility
        ) {
            public void onDrawerClosed(View view) {
                getSupportActionBar().setTitle(mTitle);
                // calling onPrepareOptionsMenu() to show action bar icons
                supportInvalidateOptionsMenu();
            }
    
            public void onDrawerOpened(View drawerView) {
                getSupportActionBar().setTitle(mDrawerTitle);
                // calling onPrepareOptionsMenu() to hide action bar icons
                supportInvalidateOptionsMenu();
            }
        };
        mDrawerLayout.setDrawerListener(mDrawerToggle);
    
    }
    
    private class SlideMenuClickListener implements
            ListView.OnItemClickListener {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position,
                long id) {
            // display view for selected nav drawer item
            displayView(position);
        }
    }
    
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // getSupportMenuInflater().inflate(R.menu.main, menu);
        return true;
    }
    
    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
    
        if (item.getItemId() == android.R.id.home) {
            if (mDrawerLayout.isDrawerOpen(mDrawerList)) {
                mDrawerLayout.closeDrawer(mDrawerList);
            } else {
                mDrawerLayout.openDrawer(mDrawerList);
            }
        }
    
        return super.onOptionsItemSelected(item);
    }
    
    /***
     * Called when invalidateOptionsMenu() is triggered
     */
    @Override
    public boolean onPrepareOptionsMenu(Menu menu) {
        // if nav drawer is opened, hide the action items
        // boolean drawerOpen = mDrawerLayout.isDrawerOpen(mDrawerList);
        // menu.findItem(R.id.action_settings).setVisible(!drawerOpen);
        return super.onPrepareOptionsMenu(menu);
    }
    
    /**
     * Diplaying fragment view for selected nav drawer list item
     * */
    private void displayView(int position) {
    
        switch (position) {
        case 0:
            Intent intent = new Intent(this, FirstActivity.class);
            startActivity(intent);
            finish();// finishes the current activity
            break;
        case 1:
            Intent intent1 = new Intent(this, SecondActivity.class);
            startActivity(intent1);
            finish();// finishes the current activity
            break;
        // case 2:
        // Intent intent2 = new Intent(this, third.class);
        // startActivity(intent2);
        // finish();
        // break;
        // case 3:
        // Intent intent3 = new Intent(this, fourth.class);
        // startActivity(intent3);
        // finish();
        // break;
        // case 4:
        // Intent intent4 = new Intent(this, fifth.class);
        // startActivity(intent4);
        // finish();
        // break;
        // case 5:
        // Intent intent5 = new Intent(this, sixth.class);
        // startActivity(intent5);
        // finish();
        // break;
        default:
            break;
        }
    
        // update selected item and title, then close the drawer
        mDrawerList.setItemChecked(position, true);
        mDrawerList.setSelection(position);
        mDrawerLayout.closeDrawer(mDrawerList);
    }
    
    @Override
    public void setTitle(CharSequence title) {
        mTitle = title;
        getActionBar().setTitle(mTitle);
    }
    
    /**
     * When using the ActionBarDrawerToggle, you must call it during
     * onPostCreate() and onConfigurationChanged()...
     */
    
    @Override
    protected void onPostCreate(Bundle savedInstanceState) {
        super.onPostCreate(savedInstanceState);
        // Sync the toggle state after onRestoreInstanceState has occurred.
        mDrawerToggle.syncState();
    }
    
    @Override
    public void onConfigurationChanged(Configuration newConfig) {
        super.onConfigurationChanged(newConfig);
        // Pass any configuration change to the drawer toggls
        mDrawerToggle.onConfigurationChanged(newConfig);
    }
    
    public class FirstActivity extends BaseActivity {
    private String[] navMenuTitles;
    private TypedArray navMenuIcons;
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_first);
        navMenuTitles = getResources().getStringArray(R.array.nav_drawer_items); 
    
    
        navMenuIcons = getResources()
                .obtainTypedArray(R.array.nav_drawer_icons);// load icons from
                                                            // strings.xml
    
        set(navMenuTitles, navMenuIcons);
        }
    
    适配器

       public class NavDrawerListAdapter extends BaseAdapter {
    
    private Context context;
    private ArrayList<NavDrawerItem> navDrawerItems;
    
    public NavDrawerListAdapter(Context context, ArrayList<NavDrawerItem> navDrawerItems){
        this.context = context;
        this.navDrawerItems = navDrawerItems;
    }
    
    @Override
    public int getCount() {
        return navDrawerItems.size();
    }
    
    @Override
    public Object getItem(int position) {       
        return navDrawerItems.get(position);
    }
    
    @Override
    public long getItemId(int position) {
        return position;
    }
    
    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        if (convertView == null) {
            LayoutInflater mInflater = (LayoutInflater)
                    context.getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
            convertView = mInflater.inflate(R.layout.drawer_list_item, null);
        }
    
        ImageView imgIcon = (ImageView) convertView.findViewById(R.id.icon);
        TextView txtTitle = (TextView) convertView.findViewById(R.id.title);
    
    
        imgIcon.setImageResource(navDrawerItems.get(position).getIcon());        
        txtTitle.setText(navDrawerItems.get(position).getTitle());
    
    
    
        return convertView;
    }
    
    }
    

    }

    在你尝试之前,没有人会为你编写代码(dude:)只要开始新的项目选择活动。谢谢Paul,你的评论真的很鼓舞人心。我请求活动只是因为我找不到如何在片段中获取远程API JSON数据。我看到的每个从远程Web API获取数据的示例都使用活动。我真的没有希望了,现在我仍在试图找到使用碎片的方法(@Harry我可以试着帮你解决这个问题,但我想我不完全理解你使用JSON的问题。你想实现什么?你能在列表中展示你需要做什么(甚至使用活动)的例子吗?谢谢你Paul。我愿意调用片段中的任何API并解析JSON,以在片段的布局文件中显示结果(线性布局)。谢谢。示例JSON API是
    public class FirstActivity extends BaseActivity {
    private String[] navMenuTitles;
    private TypedArray navMenuIcons;
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_first);
        navMenuTitles = getResources().getStringArray(R.array.nav_drawer_items); 
    
    
        navMenuIcons = getResources()
                .obtainTypedArray(R.array.nav_drawer_icons);// load icons from
                                                            // strings.xml
    
        set(navMenuTitles, navMenuIcons);
        }