my first app has stopped working error

Question

I am very new to app development. I am following the tutorial at developer.android.com and am making the "my first app" application as given on the site. I am using eclipse and Whenever i launch the app on my phone, i am given an error saying that unfortunately my first app has stopped working. What should i do??

Code:

package com.example.myfirstapp;

import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
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.os.Build;

public class MainActivity extends ActionBarActivity {

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

        if (savedInstanceState == null) {
            getSupportFragmentManager().beginTransaction()
                    .add(R.id.container, new PlaceholderFragment())
                    .commit();
        }
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {

        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, 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();
        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 {

        public PlaceholderFragment() {
        }

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

}

LogCat:

03-18 12:27:42.529: W/dalvikvm(6930): VFY: unable to resolve static field 1559 (ActionBarWindow) in Landroid/support/v7/appcompat/R$styleable;
03-18 12:27:42.529: D/dalvikvm(6930): VFY: replacing opcode 0x62 at 0x0004
03-18 12:27:42.534: D/AndroidRuntime(6930): Shutting down VM
03-18 12:27:42.534: W/dalvikvm(6930): threadid=1: thread exiting with uncaught exception (group=0x4185d2a0)
03-18 12:27:42.539: E/AndroidRuntime(6930): FATAL EXCEPTION: main
03-18 12:27:42.539: E/AndroidRuntime(6930): java.lang.NoClassDefFoundError: android.support.v7.appcompat.R$styleable
03-18 12:27:42.539: E/AndroidRuntime(6930):     at android.support.v7.app.ActionBarActivityDelegate.onCreate(ActionBarActivityDelegate.java:107)
03-18 12:27:42.539: E/AndroidRuntime(6930):     at android.support.v7.app.ActionBarActivityDelegateICS.onCreate(ActionBarActivityDelegateICS.java:58)
03-18 12:27:42.539: E/AndroidRuntime(6930):     at android.support.v7.app.ActionBarActivity.onCreate(ActionBarActivity.java:98)
03-18 12:27:42.539: E/AndroidRuntime(6930):     at com.example.myfirstapp.MainActivity.onCreate(MainActivity.java:18)
03-18 12:27:42.539: E/AndroidRuntime(6930):     at android.app.Activity.performCreate(Activity.java:5188)
03-18 12:27:42.539: E/AndroidRuntime(6930):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1094)
03-18 12:27:42.539: E/AndroidRuntime(6930):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2074)
03-18 12:27:42.539: E/AndroidRuntime(6930):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2135)
03-18 12:27:42.539: E/AndroidRuntime(6930):     at android.app.ActivityThread.access$700(ActivityThread.java:140)
03-18 12:27:42.539: E/AndroidRuntime(6930):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1237)
03-18 12:27:42.539: E/AndroidRuntime(6930):     at android.os.Handler.dispatchMessage(Handler.java:99)
03-18 12:27:42.539: E/AndroidRuntime(6930):     at android.os.Looper.loop(Looper.java:137)
03-18 12:27:42.539: E/AndroidRuntime(6930):     at android.app.ActivityThread.main(ActivityThread.java:4921)
03-18 12:27:42.539: E/AndroidRuntime(6930):     at java.lang.reflect.Method.invokeNative(Native Method)
03-18 12:27:42.539: E/AndroidRuntime(6930):     at java.lang.reflect.Method.invoke(Method.java:511)
03-18 12:27:42.539: E/AndroidRuntime(6930):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1038)
03-18 12:27:42.539: E/AndroidRuntime(6930):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:805)
03-18 12:27:42.539: E/AndroidRuntime(6930):     at dalvik.system.NativeStart.main(Native Method)

Answer 1

change apptheme to Theme.AppCompat in your manifest.xml

<application
...
 android:theme="@style/Theme.AppCompat" >

Answer 2

add following to the manifest file

<uses-sdk
    android:minSdkVersion="16"
    android:targetSdkVersion="18" />