XML : Set TableLayout programmatically to content_main.xml

I am new in android developing and have my problems by develop my UI what looks easy but doesn't work. I have a method for my App which should built me a new UI.

It should create a tableLayout with x table rows. I don't know before how many that are so I do it in Code. But I see nothing and get no Errors/Warnings.

Here my Code from MainActivity.java:

  private void buildNewUI(PatientRepository repoPatient, ExternalSystemsRepository repoExtSys){        TableLayout tableLayout = new TableLayout(this);      tableLayout.setLayoutParams(new TableRow.LayoutParams(TableRow.LayoutParams.MATCH_PARENT, TableRow.LayoutParams.MATCH_PARENT));      tableLayout.setStretchAllColumns(true);        Iterator patIterator = repoPatient.getIterator();        while(patIterator.hasNext()){          TableRow row = new TableRow(this);          Patient patient = (Patient) patIterator.next();          TextView outputLeft = new TextView(this);          outputLeft.setText(patient.getSurname());          row.addView(outputLeft);          tableLayout.addView(row);      }    }    

Activity_main.xml:

  <?xml version="1.0" encoding="utf-8"?>  <android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"      xmlns:app="http://schemas.android.com/apk/res-auto"      xmlns:tools="http://schemas.android.com/tools"      android:layout_width="match_parent"      android:layout_height="match_parent"      android:fitsSystemWindows="true"      tools:context="com.patientfinder.MainActivity">        <android.support.design.widget.AppBarLayout          android:layout_width="match_parent"          android:layout_height="wrap_content"          android:theme="@style/AppTheme.AppBarOverlay">            <android.support.v7.widget.Toolbar              android:id="@+id/toolbar"              android:layout_width="match_parent"              android:layout_height="?attr/actionBarSize"              android:background="?attr/colorPrimary"              app:popupTheme="@style/AppTheme.PopupOverlay" />        </android.support.design.widget.AppBarLayout>        <include layout="@layout/content_main" />    </android.support.design.widget.CoordinatorLayout>      and content_main.xml:        <?xml version="1.0" encoding="utf-8"?>      <TableLayout xmlns:android="http://schemas.android.com/apk/res/android"      xmlns:app="http://schemas.android.com/apk/res-auto"      xmlns:tools="http://schemas.android.com/tools"      android:layout_width="match_parent"      android:layout_height="match_parent"      android:paddingBottom="@dimen/activity_vertical_margin"      android:paddingLeft="@dimen/activity_horizontal_margin"      android:paddingRight="@dimen/activity_horizontal_margin"      android:paddingTop="@dimen/activity_vertical_margin"      app:layout_behavior="@string/appbar_scrolling_view_behavior"      tools:context="com.patientfinder.MainActivity"      tools:showIn="@layout/activity_main">  </TableLayout>    

What is my mistake?