The widgets in a new activity not showing up - user-interface

Question

I am working on an application that has a button which will lead to a new activity. I managed to make that work but when I am trying to add a button in the new activity with xml it is not showing up. I tried to make it work with programming but I was only able to make a button big as the whole screen. When I tried to change the size of the button with programming it could not work. Can someone please tell me how can I make that widgets show on the new activity preferably using XML.
This is the code of my first activity:
package com.example.user.myapp;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.MenuInflater;
import android.view.View;
import android.content.Intent;
public class MainActivity extends ActionBarActivity {
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.activity_main_actions, menu);
return super.onCreateOptionsMenu(menu);
}
public void sendButton(View view){
Intent intent = new Intent(this, Ut.class);
startActivity(intent);
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
And this is the code of my second activity:
package com.example.user.myapp;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.widget.Button;
import android.content.Intent;
public class Ut extends ActionBarActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Intent intent = getIntent();
setContentView(R.layout.activity_ut);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.activity_main_actions, menu);
return super.onCreateOptionsMenu(menu);
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
and this is the code that I added after Intent intent = getIntent() when I tried to make it work with programming
Button button2 = new Button(this);
button2.setWidth(10);
button2.setHeight(10);
setContentView(button2);
With this code a button big as the whole screen showed up although I set the size of it.
Can somebody tell me how I can make this work?