1. Adding Components to Activity
We have two options:
1- Creating a xml layout file with button in it.
2- Adding button dynamically to your Activity.

2. 1- Creating a xml layout file with button in it.
<LinearLayout xmlns:android="
xmlns:tools=" android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="TableLayout"
/>
</LinearLayout>
and use this layout in your Activity:
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button myTableButton=(Button) findViewById(R.id.button);
myTableButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Log.d("Hi", "hi"); }
});

3. 2- Adding button dynamically to your Activity.
<LinearLayout xmlns:android="
xmlns:tools=" android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="TableLayout"
/>
<LinearLayout
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="fill_parent"></LinearLayout>
</LinearLayout>
*******************************Add this to your main activity.
LinearLayout layout = (LinearLayout) findViewById(R.id.layout1);
layout.setOrientation(LinearLayout.HORIZONTAL);
Button myNew;
myNew = new Button(this);
myNew.setText("Hi");
layout.addView(myNew);
myNew.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Log.d("First","Log"); }
});
Button btn = new Button(this);
btn.setText("OK1");
layout.addView(btn);
...