I have seen many customized solutions and answers to this question. I need something very simple, I have a preference activity and all I need is that one of the options will open dialog with a number picker and save the results. Can you please guide me step by step with how to accomplish this?
public class SettingsActivity extends PreferenceActivity
{
    @Override
    protected void onCreate(final Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        getFragmentManager().beginTransaction().replace(android.R.id.content, new MyPreferenceFragment()).commit();
        //requestWindowFeature(Window.FEATURE_NO_TITLE);    
    }
    public static class MyPreferenceFragment extends PreferenceFragment
    {
        @Override
        public void onCreate(final Bundle savedInstanceState)
        {
            super.onCreate(savedInstanceState);
            addPreferencesFromResource(R.xml.prefs);
        }
    }
}
XML:
    <SwitchPreference
        android:key="cross"
        android:summaryOff="Cross is invisible"
        android:summaryOn="Cross is visible"
        android:switchTextOff="OFF"
        android:switchTextOn="ON"
        android:title="Cross" 
        android:defaultValue="true"/>
    <SwitchPreference
        android:key="autoP"
        android:summaryOff="App will go to sleep"
        android:summaryOn="App will not go to sleep"
        android:switchTextOff="OFF"
        android:switchTextOn="ON"
        android:title="Always On" 
        android:defaultValue="true"/>
    <SwitchPreference
        android:key="tempD"
        android:summaryOff="Temprature not displayed"
        android:summaryOn="Temprature displayed"
        android:switchTextOff="OFF"
        android:switchTextOn="ON"
        android:title="Tempature Display" 
        android:defaultValue="true"/>
    <ListPreference
        android:entries="@array/units"
        android:entryValues="@array/lunits"
        android:key="listUnits"
        android:summary="Units schosssing"
        android:title="Units" android:defaultValue="C"/>
     <!--Need to add button to open dialog-->       
</PreferenceScreen>
Number Picker XML:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" >
    <NumberPicker
        android:id="@+id/numberPicker1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="64dp" />
    <Button
        android:id="@+id/button2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/numberPicker1"
        android:layout_marginLeft="20dp"
        android:layout_marginTop="98dp"
        android:layout_toRightOf="@+id/numberPicker1"
        android:text="Cancel" />
    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/button2"
        android:layout_alignBottom="@+id/button2"
        android:layout_marginRight="16dp"
        android:layout_toLeftOf="@+id/numberPicker1"
        android:text="Set" />
</RelativeLayout>
 
     
     
     
     
    