adding cardviews to scroll view dynamically, not showing

Question

I am attempting to add card views to a scroll view dynamically. so I am adding these cardviews to a linear layout which is situated inside a scrollview in my xml. However when I press the fab button I don't see anything. I don't know why. Is it something to do with layoutparams?

This is my create.java

public class create extends AppCompatActivity {

    Button button;
    Context context;
    CardView cardview;
    LayoutParams layoutparams;
    TextView textview;
    LinearLayout linearLayout;
    ScrollView scrollView;

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

        button = (Button)findViewById(R.id.button);

        context = getApplicationContext();

        linearLayout = (LinearLayout) findViewById(R.id.linearlayout1);

        scrollView = (ScrollView)findViewById(R.id.scrollView1);

        //TODO FAB BUTTON
        FloatingActionButton floatingActionButton =
                (FloatingActionButton) findViewById(R.id.fab);


        floatingActionButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {

                createCardViewProgrammatically();

            }
        });
    }

    public void createCardViewProgrammatically(){


        CardView card = new CardView(context);

        // Set the CardView layoutParams
        LayoutParams params = new LayoutParams(
                LayoutParams.WRAP_CONTENT,
                LayoutParams.WRAP_CONTENT
        );
        card.setLayoutParams(params);

        // Set CardView corner radius
        card.setRadius(9);

        // Set cardView content padding
        card.setContentPadding(15, 15, 15, 15);

        // Set a background color for CardView
        card.setCardBackgroundColor(Color.parseColor("#FFC6D6C3"));

        // Set the CardView maximum elevation
        card.setMaxCardElevation(15);

        // Set CardView elevation
        card.setCardElevation(9);

        // Initialize a new TextView to put in CardView
        TextView tv = new TextView(context);
        tv.setLayoutParams(params);
        tv.setText("CardView\nProgrammatically");
        tv.setTextSize(TypedValue.COMPLEX_UNIT_DIP, 30);
        tv.setTextColor(Color.RED);

        // Put the TextView in CardView
        card.addView(tv);

        // Finally, add the CardView in root layout
        linearLayout.addView(card);


    }

}

and this is my xml file

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout 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:background="@color/colorBackground"
    android:minHeight="170dp"
    tools:context=".create"
    tools:layout_editor_absoluteY="81dp"
    >




    <ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/scrollView1"
        android:layout_width="match_parent"
        android:layout_height="438dp"
        android:fillViewport="true"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="1.0"
        app:layout_constraintStart_toStartOf="parent"
        tools:layout_editor_absoluteY="0dp">

        <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
            xmlns:tools="http://schemas.android.com/tools"
            android:layout_width="match_parent"
            android:layout_height="match_parent"

            tools:context="com.android_examples.cardviewprogrammatically_android_examplescom.MainActivity"
            android:id="@+id/linearlayout1">


        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Click here to Create CardView programmatically on Button click"
            android:id="@+id/button"
            android:layout_centerVertical="true"
            android:layout_centerHorizontal="true" />
        </LinearLayout>
    </ScrollView>








    <android.support.design.widget.FloatingActionButton
        android:id="@+id/fab"
        android:layout_width="60dp"
        android:layout_height="70dp"
        android:layout_gravity="bottom|end"
        android:layout_marginBottom="16dp"
        android:layout_marginEnd="16dp"
        android:layout_marginLeft="8dp"
        android:layout_marginRight="16dp"
        android:layout_marginStart="8dp"
        android:src="@android:drawable/ic_input_add"
        app:backgroundTint="@color/colorCreate"
        app:elevation="6dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="1.0"
        app:layout_constraintStart_toStartOf="parent"
        app:pressedTranslationZ="12dp"
        android:tint="@color/colorBackground"/>



    <View
        android:id="@+id/subheading"
        android:layout_width="match_parent"
        android:layout_height="83dp"
        android:layout_marginBottom="8dp"
        android:layout_marginEnd="1dp"
        android:layout_marginLeft="1dp"
        android:layout_marginRight="1dp"
        android:layout_marginStart="1dp"
        android:layout_marginTop="2dp"
        android:background="@color/colorBackground"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.0"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.0"
        />

    <View
        android:id="@+id/view"
        android:layout_width="320dp"
        android:layout_height="1dp"
        android:layout_marginEnd="8dp"
        android:layout_marginLeft="8dp"
        android:layout_marginRight="8dp"
        android:layout_marginStart="8dp"
        android:layout_marginTop="76dp"
        android:background="@color/colorText"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <View
        android:id="@+id/view2"
        android:layout_width="320dp"
        android:layout_height="1dp"
        android:layout_marginEnd="8dp"
        android:layout_marginLeft="8dp"
        android:layout_marginRight="8dp"
        android:layout_marginStart="8dp"
        android:layout_marginTop="28dp"
        android:background="@color/colorText"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginEnd="8dp"
        android:layout_marginLeft="8dp"
        android:layout_marginRight="8dp"
        android:layout_marginStart="8dp"

        android:layout_marginTop="12dp"
        android:text="@string/done_label"
        android:textColor="@color/colorText"
        android:textSize="20sp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toEndOf="@+id/textView4"
        app:layout_constraintTop_toBottomOf="@+id/view2" />

    <TextView
        android:id="@+id/textView4"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="8dp"
        android:layout_marginEnd="128dp"
        android:layout_marginRight="128dp"
        android:layout_marginTop="8dp"
        android:text="@string/aisle_label"
        android:textColor="@color/colorText"
        android:textSize="20sp"
        app:layout_constraintBottom_toTopOf="@+id/view"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/view2"
        app:layout_constraintVertical_bias="1.0" />

    <TextView
        android:id="@+id/textView3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="5dp"
        android:layout_marginEnd="32dp"
        android:layout_marginRight="32dp"
        android:layout_marginTop="5dp"
        android:text="@string/qty_label"
        android:textColor="@color/colorText"
        android:textSize="20sp"
        app:layout_constraintBottom_toTopOf="@+id/view"
        app:layout_constraintEnd_toStartOf="@+id/textView4"
        app:layout_constraintTop_toBottomOf="@+id/view2"
        app:layout_constraintVertical_bias="0.7" />

    <TextView
        android:id="@+id/textView2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginLeft="8dp"
        android:layout_marginRight="8dp"
        android:layout_marginStart="8dp"
        android:layout_marginTop="8dp"
        android:text="@string/item_label"
        android:textColor="@color/colorText"
        android:textSize="20sp"
        app:layout_constraintBottom_toTopOf="@+id/view"
        app:layout_constraintEnd_toStartOf="@+id/textView3"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/view2"
        app:layout_constraintVertical_bias="1.0" />






</android.support.constraint.ConstraintLayout>

Answer 1

You need to specify the Orientation of your LinearLayout as VERTICAL

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"
        tools:context="com.android_examples.cardviewprogrammatically_android_examplescom.MainActivity"
        android:id="@+id/linearlayout1">