tabactivity 在 mainactivity 从 activity 扩展时崩溃

tabactivity crashing when mainactivity extended from activity

Tabactivity 初始化时崩溃。我已经从 Activity 扩展了 main activity。如果我从 activity 扩展 tabactivity,它会返回很多错误。请帮忙,因为我是 android 的绝对初学者

    package mavilla.paavaiinstitutions;

import java.util.Locale;

import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.support.v4.app.FragmentPagerAdapter;
import android.os.Bundle;
import android.support.v4.view.ViewPager;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;


public class TabActivity_about extends ActionBarActivity {

    /**
     * The {@link android.support.v4.view.PagerAdapter} that will provide
     * fragments for each of the sections. We use a
     * {@link FragmentPagerAdapter} derivative, which will keep every
     * loaded fragment in memory. If this becomes too memory intensive, it
     * may be best to switch to a
     * {@link android.support.v4.app.FragmentStatePagerAdapter}.
     */
    SectionsPagerAdapter mSectionsPagerAdapter;

    /**
     * The {@link ViewPager} that will host the section contents.
     */
    ViewPager mViewPager;

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


        // Create the adapter that will return a fragment for each of the three
        // primary sections of the activity.
        mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());

        // Set up the ViewPager with the sections adapter.
        mViewPager = (ViewPager) findViewById(R.id.pager);
        mViewPager.setAdapter(mSectionsPagerAdapter);

    }


    @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_tab_activity_about, 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.
        int id = item.getItemId();

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

        return super.onOptionsItemSelected(item);
    }


    /**
     * A {@link FragmentPagerAdapter} that returns a fragment corresponding to
     * one of the sections/tabs/pages.
     */
    public class SectionsPagerAdapter extends FragmentPagerAdapter {

        public SectionsPagerAdapter(FragmentManager fm) {
            super(fm);
        }

        @Override
        public Fragment getItem(int position) {
            // getItem is called to instantiate the fragment for the given page.
            // Return a PlaceholderFragment (defined as a static inner class below).
            return PlaceholderFragment.newInstance(position + 1);
        }

        @Override
        public int getCount() {
            // Show 9 total pages.
            return 3;
        }

        @Override
        public CharSequence getPageTitle(int position) {
            Locale l = Locale.getDefault();
            switch (position) {
                case 0:
                    return getString(R.string.About_us).toUpperCase(l);
                case 1:
                    return getString(R.string.History).toUpperCase(l);
                case 2:
                    return getString(R.string.Ideals).toUpperCase(l);
                case 3:
                    return getString(R.string.Objectives).toUpperCase(l);
                case 4:
                    return getString(R.string.Vision_mission).toUpperCase(l);
                case 5:
                    return getString(R.string.Quality).toUpperCase(l);
                case 6:
                    return getString(R.string.chairman).toUpperCase(l);
                case 7:
                    return getString(R.string.Trust).toUpperCase(l);
                case 8:
                    return getString(R.string.Management).toUpperCase(l);
            }
            return null;
        }
    }

    /**
     * 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_tab_activity_about, container, false);
            return rootView;
        }
    }

}

这是 logcat

01-02 15:21:54.287    1597-1616/mavilla.paavaiinstitutions W/OpenGLRenderer﹕ Failed to set EGL_SWAP_BEHAVIOR on surface 0xa46192a0, error=EGL_SUCCESS
01-02 15:23:34.627    1597-1597/mavilla.paavaiinstitutions D/AndroidRuntime﹕ Shutting down VM
    --------- beginning of crash
01-02 15:23:34.628    1597-1597/mavilla.paavaiinstitutions E/AndroidRuntime﹕ FATAL EXCEPTION: main
    Process: mavilla.paavaiinstitutions, PID: 1597
    java.lang.RuntimeException: Unable to start activity ComponentInfo{mavilla.paavaiinstitutions/mavilla.paavaiinstitutions.TabActivity_about}: java.lang.IllegalStateException: You need to use a Theme.AppCompat theme (or descendant) with this activity.
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2298)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
            at android.app.ActivityThread.access0(ActivityThread.java:144)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5221)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
     Caused by: java.lang.IllegalStateException: You need to use a Theme.AppCompat theme (or descendant) with this activity.
            at android.support.v7.app.ActionBarActivityDelegate.onCreate(ActionBarActivityDelegate.java:151)
            at android.support.v7.app.ActionBarActivityDelegateBase.onCreate(ActionBarActivityDelegateBase.java:138)
            at android.support.v7.app.ActionBarActivity.onCreate(ActionBarActivity.java:123)
            at mavilla.paavaiinstitutions.TabActivity_about.onCreate(TabActivity_about.java:41)
            at android.app.Activity.performCreate(Activity.java:5933)
            at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2251)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
            at android.app.ActivityThread.access0(ActivityThread.java:144)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5221)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)

请参阅 https://developer.android.com/training/basics/actionbar/styling.html 了解操作栏的样式。您基本上必须编辑 styles.xml