How to add a TextView to a LinearLayout dynamically in Android?

LayoutParams lparams = new LayoutParams(
   LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
TextView tv=new TextView(this);
tv.setLayoutParams(lparams);
tv.setText("test");
this.m_vwJokeLayout.addView(tv);

You can change lparams according to your needs

Here is a more general answer for future viewers of this question. The layout we will make is below:

Method 1: Add TextView to existing LinearLayout

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

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

    // Add textview 1
    TextView textView1 = new TextView(this);
    textView1.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT,
            LayoutParams.WRAP_CONTENT));
    textView1.setText("programmatically created TextView1");
    textView1.setBackgroundColor(0xff66ff66); // hex color 0xAARRGGBB
    textView1.setPadding(20, 20, 20, 20);// in pixels (left, top, right, bottom)
    linearLayout.addView(textView1);

    // Add textview 2
    TextView textView2 = new TextView(this);
    LayoutParams layoutParams = new LayoutParams(LayoutParams.WRAP_CONTENT,
            LayoutParams.WRAP_CONTENT);
    layoutParams.gravity = Gravity.RIGHT;
    layoutParams.setMargins(10, 10, 10, 10); // (left, top, right, bottom)
    textView2.setLayoutParams(layoutParams);
    textView2.setText("programmatically created TextView2");
    textView2.setTextSize(TypedValue.COMPLEX_UNIT_SP, 18);
    textView2.setBackgroundColor(0xffffdbdb); // hex color 0xAARRGGBB
    linearLayout.addView(textView2);
}

Note that for LayoutParams you must specify the kind of layout for the import, as in

import android.widget.LinearLayout.LayoutParams;

Otherwise you need to use LinearLayout.LayoutParams in the code.

Here is the xml:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/ll_example"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#ff99ccff"
    android:orientation="vertical" >

</LinearLayout>

Method 2: Create both LinearLayout and TextView programmatically

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    // NOTE: setContentView is below, not here

    // Create new LinearLayout
    LinearLayout linearLayout = new LinearLayout(this);
    linearLayout.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT,
            LayoutParams.MATCH_PARENT));
    linearLayout.setOrientation(LinearLayout.VERTICAL);
    linearLayout.setBackgroundColor(0xff99ccff);

    // Add textviews
    TextView textView1 = new TextView(this);
    textView1.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT,
            LayoutParams.WRAP_CONTENT));
    textView1.setText("programmatically created TextView1");
    textView1.setBackgroundColor(0xff66ff66); // hex color 0xAARRGGBB
    textView1.setPadding(20, 20, 20, 20); // in pixels (left, top, right, bottom)
    linearLayout.addView(textView1);

    TextView textView2 = new TextView(this);
    LayoutParams layoutParams = new LayoutParams(LayoutParams.WRAP_CONTENT,
            LayoutParams.WRAP_CONTENT);
    layoutParams.gravity = Gravity.RIGHT;
    layoutParams.setMargins(10, 10, 10, 10); // (left, top, right, bottom)
    textView2.setLayoutParams(layoutParams);
    textView2.setText("programmatically created TextView2");
    textView2.setTextSize(TypedValue.COMPLEX_UNIT_SP, 18);
    textView2.setBackgroundColor(0xffffdbdb); // hex color 0xAARRGGBB
    linearLayout.addView(textView2);

    // Set context view
    setContentView(linearLayout);
}

Method 3: Programmatically add one xml layout to another xml layout

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

    LayoutInflater inflater = (LayoutInflater) getApplicationContext().getSystemService(
            Context.LAYOUT_INFLATER_SERVICE);
    View view = inflater.inflate(R.layout.dynamic_linearlayout_item, null);
    FrameLayout container = (FrameLayout) findViewById(R.id.flContainer);
    container.addView(view);
}

Here is dynamic_linearlayout.xml:

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/flContainer"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

</FrameLayout>

And here is the dynamic_linearlayout_item.xml to add:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/ll_example"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#ff99ccff"
    android:orientation="vertical" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="#ff66ff66"
        android:padding="20px"
        android:text="programmatically created TextView1" />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="#ffffdbdb"
        android:layout_gravity="right"
        android:layout_margin="10px"
        android:textSize="18sp"
        android:text="programmatically created TextView2" />

</LinearLayout>