Spacing not working between Views in Android

Question

I am trying to create views at runtime and I want to have the main layout view which is blank and then at runtime add a view that is a dotted line box (a group view) and then add other views inside that view (item views). I have that working, but I am currently testing it with two group views, but when they are added, they are added straight after each other and there is no spacing between the dotted line views. I don't really understand why this is, because I have tried every combination of margin and padding to try and do this, but nothing works. Please can someone help me with this. Thank you in advance.

Here is my code for the group layout view:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:background="@drawable/group_box"
    android:layout_marginBottom="@dimen/activity_vertical_margin"
    android:id="@+id/pvGroupContainerLayout" >

<TextView
    android:id="@+id/groupBoxTextView1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:paddingLeft="8dp"
    android:paddingTop="4dp"
    android:paddingBottom="@dimen/activity_vertical_margin" />

</LinearLayout>

Here is the code that adds the views:

public void createView()
{
    deviceInfoContainer = new DeviceInfoContainer(activity);
    TextView deviceInfoTextView1 = deviceInfoContainer.getDeviceInfoTextView1();
    TextView deviceInfoTextView2 = deviceInfoContainer.getDeviceInfoTextView2();
    TextView deviceInfoTextView3 = deviceInfoContainer.getDeviceInfoTextView3();
    View deviceInfoView = deviceInfoContainer.getDeviceInfoView();

    deviceInfoTextView1.setText(deviceInfo.getDeviceTypeName());
    deviceInfoTextView2.setText(String.valueOf(deviceInfo.getDeviceTypeCode()));
    deviceInfoTextView3.setText(String.valueOf(deviceInfo.getSensorTypeObject()));

    pvContainerLayout.addView(deviceInfoView);

    System.out.println("Page test: " + page.getAttributeName());
    ArrayList<Group> groups = page.returnGroups();
    System.out.println("Groups test: " + groups.size());

    for(Group g : groups)
    {
        groupContainer = new PVGroupContainer(activity);
        groupContainerList.add(groupContainer);
        TextView groupTextView = groupContainer.getGroupTextView();
        View groupView = groupContainer.getGroupView();
        groupTextView.setText(g.getAttributeName());
        pvContainerLayout.addView(groupView);

        for(Item i : g.returnItems())
        {
            DataObject dataObject = i.getDataObject();

            if(dataObject.getClass().equals(StringDataObject.class))
            {
                StringDataObject stringDataObject = (StringDataObject) dataObject;

                itemContainer = new PVItemContainer(activity); // Declares new object in the array list
                itemContainerList.add(itemContainer);

                TextView progressBarTextView1 = itemContainer.getProgressBarTextView1();
                TextView progressBarTextView2 = itemContainer.getProgressBarTextView2();
                ProgressBar progressBarProgressBar1 = itemContainer.getProgressBarProgressBar1();
                View progressBarView = itemContainer.getProgressBarView();
                ImageButton progressBarImageButton1 = itemContainer.getProgressBarImageButton1();

                progressBarTextView1.setText(i.getAttributeName());
                progressBarTextView2.setText(stringDataObject.getValue());
                progressBarProgressBar1.setProgress(0); //TODO: String will be "" which is invalid. May need to change the view.
                ((ViewGroup) groupView).addView(progressBarView); // Adds the view to the current layout
                progressBarView.setOnLongClickListener(new OnLongClickListener() 
                {
                    @Override
                    public boolean onLongClick(View v) {
                        Vibrator vibrator = (Vibrator)activity.getSystemService(Context.VIBRATOR_SERVICE);
                        vibrator.vibrate(1500);
                        popupFirmware.createDialog();
                        return true;
                    }   
                });

                progressBarImageButton1.setOnClickListener(new OnClickListener() 
                {
                    @Override
                    public void onClick(View v) {
                        Fragment fragment = new Fragment_3();
                        FragmentTransaction transaction = ((FragmentActivity) activity).getSupportFragmentManager().beginTransaction();
                        transaction.replace(R.layout.fragment_diag, fragment);
                        transaction.addToBackStack(null);
                        transaction.commit();
                    }
                });
            }
       }
}