ListView set the item as checked to be highlighted

If You create new xml file with prefix _ , for example _style.xml and You to clean project (Project->Clean), than package in folder project\gen will deleted with R.java class and new R.java not be created.

For to solving this problem You have to rename file without prefix _ as style.xml or name what You need and rebuild project.

If some ID cannot be resolved or is not a field get error occurence
You have to delete import android.R; in Activity.class if was inserted,
when this error is displayed.

[2013-07-06 16:10:29 - SDK Manager] [SDK Manager] Error: Error parsing the sdk.
[2013-07-06 16:10:29 - SDK Manager] [SDK Manager] Error: Failed to create C:\Program Files\android\sdk\add-ons.
[2013-07-06 16:10:29 - SDK Manager] [SDK Manager] Error: Unable to parse SDK content.

You have to create add-ons folder as admin of PC

Date difference in millisecond between two date, GregorianCalendar, Calendar, after(), befor(), getTimeInMillis().

public class HoriziontalScrollActivity extends Activity {
TextView txtV;
	Context cntx;
	
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        txtV = (TextView)findViewById(R.id.idLabel);
        cntx = this;
        StringBuilder strBuild = new StringBuilder();
        Calendar firstDate = new GregorianCalendar(2011, Calendar.DECEMBER, 31);
        Calendar secondDate = new GregorianCalendar(2012, Calendar.JANUARY, 1);

        
        Boolean bDetermine = firstDate.after(secondDate);            // false
        strBuild.append("Is firsDate after secondDate? " + bDetermine + "

");
        bDetermine = firstDate.before(secondDate);                   // true
        strBuild.append("Is firsDate before secondDate? " + bDetermine + "

");
        
        
        long differenceInMillisecond = 0L;
         differenceInMillisecond = secondDate.getTimeInMillis()-firstDate.getTimeInMillis();
         // second == 1000 millisecond
         long second = differenceInMillisecond / 1000L;
         strBuild.append("Difference between two dates is: " + second + "

");
        
         txtV.setText(strBuild);

    }
  
}

If the app have transparent menu and you do not want this,
try delete @style/AppTheme in application tag in AndroidManifest.xml
and try run module - project. If menu is not transparent , maybe it caused

 <application
        android:allowBackup="true"
        android:icon="@drawable/dicts_ico"
        android:label="@string/app_name" 
        android:theme="@style/AppTheme" // delete this row - run app - try menu
 >

Or try set values\styles.xml into basic Theme

<resources>

    <!--
        Base application theme, dependent on API level. This theme is replaced
        by AppBaseTheme from res/values-vXX/styles.xml on newer devices.
    -->
    <style name="AppBaseTheme" parent="android:Theme.Black">
        <!--
            Theme customizations available in newer API levels can go in
            res/values-vXX/styles.xml, while customizations related to
            backward-compatibility can go here.
        -->
    </style>

    <!-- Application theme. -->
    <style name="AppTheme" parent="AppBaseTheme">
        <!-- All customizations that are NOT specific to a particular API-level can go here. -->
    </style>

</resources>

Try reboot device.
Start device with start button on side of phone.
Screen will go to light black color.
Long press Start button for menu:
Power off
Reboot
Airplane mode

Reboot item is in same level like Start button.
Click on the screen - (Hear a click)
Now find OK button , it is under Reboot item on right side of screen.
Press OK (Hear a click)
Wait a moment.
If device to do nothing , try short press Start button (sreen will black)
and again to press Start button. If screen go to light black color,
try again find Reboot item as written above.