인트로 화면 구성을 하는데 인트로 화면은 뜨고 메인 화면으로 넘어가지가 않아요

Question

 인트로액티비티.java 입니다  

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

       Handler handler = new Handler();
        handler.postDelayed(new Runnable() {
            public void run() {
                Intent intent = new Intent(getApplicationContext(),MainActivity.class);
                startActivity(intent);
                finish();
            }
        }, 3000);
        }
}

 

 

 

manifest 입니다

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.administrator.soapplication1" >

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".IntroActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity android:name=".MainActivity" android:label="main Activity" />
        <activity android:name=".Sub1Activity" android:label="1 Activity" />
        <activity android:name=".Sub2Activity" android:label="2 Activity" />
        <activity android:name=".Sub3Activity" android:label="3 Activity" />
        <activity android:name=".Sub4Activity" android:label="4 Activity" />
    </application>

</manifest>