Question

我试图创建一个导航抽屉。我已经创建了它，但问题是当我第一次打开应用程序时，片段会显示在内容区域中，但它不会在导航栏中突出显示。

这是我使用的代码：

    package com.hfad.evenit;

    import android.app.Fragment;
    import android.app.FragmentTransaction;
    import android.content.res.Configuration;
    import android.support.v4.widget.DrawerLayout;
    import android.support.v7.app.ActionBarDrawerToggle;
    import android.support.v7.app.AppCompatActivity;
    import android.os.Bundle;
    import android.view.Menu;
    import android.view.MenuItem;
    import android.view.View;
    import android.widget.AdapterView;
    import android.widget.ArrayAdapter;
    import android.widget.ListView;

    import com.hfad.evenit.Fragments.FourthFragment;
    import com.hfad.evenit.Fragments.SecondFragment;
    import com.hfad.evenit.Fragments.ThirdFragment;
    import com.hfad.evenit.Fragments.TopFragment;

    public class Home extends AppCompatActivity {

        String []FragmentTitles;
        ListView DrawerList;
        DrawerLayout drawerLayout;
        ActionBarDrawerToggle drawerToggle;
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.home);

            FragmentTitles = getResources().getStringArray(R.array.fragment_titles);
            DrawerList = (ListView) findViewById(R.id.drawer);

            drawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
            DrawerList.setAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_list_item_activated_1, FragmentTitles));

            DrawerList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
                @Override
                public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                    selectItem(position);
                }
            });


            selectItem(0);
            DrawerList.setSelection(0);


            drawerToggle = new ActionBarDrawerToggle(this, drawerLayout, R.string.open_drawer, R.string.close_drawer) {
                @Override
                public void onDrawerClosed(View view) {
                    super.onDrawerClosed(view);
                    invalidateOptionsMenu();
                }

                @Override
                public void onDrawerOpened(View drawerView) {
                    super.onDrawerOpened(drawerView);
                    invalidateOptionsMenu();
                }
            };
          drawerLayout.setDrawerListener(drawerToggle);

            getSupportActionBar().setDisplayHomeAsUpEnabled(true);
            getSupportActionBar().setHomeButtonEnabled(true);

        }

        @Override
        public void onConfigurationChanged(Configuration newConfig) {
            super.onConfigurationChanged(newConfig);
            drawerToggle.onConfigurationChanged(newConfig);
        }

        @Override
        protected void onPostCreate(Bundle savedInstanceState) {
            super.onPostCreate(savedInstanceState);
            drawerToggle.syncState();
        }

        @Override
        public boolean onPrepareOptionsMenu(Menu menu) {

            boolean drawerOpen = drawerLayout.isDrawerOpen(DrawerList);
            menu.findItem(R.id.action_share).setVisible(!drawerOpen);
            return super.onPrepareOptionsMenu(menu);
        }

        @Override
        public boolean onCreateOptionsMenu(Menu menu) {
            // Inflate the menu; this adds items to the action bar if it is present.
            getMenuInflater().inflate(R.menu.menu_home, menu);
            return true;
        }

        @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.
            if(drawerToggle.onOptionsItemSelected(item))
            {
                return  true;
            }
            int id = item.getItemId();

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

            return super.onOptionsItemSelected(item);
        }

        public void selectItem(int position)
        {
            Fragment fragment;
            switch(position)
            {
                case 0:
                    fragment = new TopFragment();
                    break;
                case 1:
                    fragment = new SecondFragment();
                    break;
                case 2:
                    fragment = new ThirdFragment();
                    break;
                case 3:
                    fragment = new FourthFragment();
                    break;
                default:
                    fragment = new TopFragment();
            }

            FragmentTransaction ft = getFragmentManager().beginTransaction();
            ft.replace(R.id.content_frame, fragment);
            ft.addToBackStack(null);
            ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
            ft.commit();

            setActionBarTitle(position);

            drawerLayout.closeDrawer(DrawerList);

        }

        public void setActionBarTitle(int position)
        {
            String title;
            title = FragmentTitles[position];
            getSupportActionBar().setTitle(title);
        }

}

Answer 1

您应该使用的方法将项目状态更改为＆＃34;突出显示＆＃34;或目前已激活setItemChecked(int position, boolean value)。最好将它放在selectItem方法中，以便突出显示＆＃34;＆＃34;调用SelectItem方法后，项目会更改。

您可能还需要考虑将listView的选择模式设置为CHOICE_MODE_SINGLE，以便在给定时间只有一个项目可以处于活动状态。

drawerList.setChoiceMode(CHOICE_MODE_SINGLE);

Answer 2

在这附近......

public void selectItem(int position) {

    ...

    setActionBarTitle(position);

    drawerLayout.closeDrawer(DrawerList);
}

添加DrawerList.setItemChecked(position, true);可能有用。

public void selectItem(int position) {

    ...

    setActionBarTitle(position);

    DrawerList.setItemChecked(position, true); // <== add this line

    drawerLayout.closeDrawer(DrawerList);
}

实际上，我最近没有使用Android Studio项目模板的导航抽屉，而是使用NavigationView（建议易于使用）。如果我的回答无效，请忘记这一点。

项目未在导航栏中突出显示

2 个答案: