UI Android

package app.test;
import android.app.Activity;
import android.os.Bundle;
import android.view.ViewGroup.LayoutParams;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.TextView;
public class Test extends Activity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //setContentView(R.layout.main);
        LayoutParams params = 
            new LinearLayout.LayoutParams(
                LayoutParams.FILL_PARENT,
                LayoutParams.WRAP_CONTENT);
        LinearLayout layout = new LinearLayout(this);
        layout.setOrientation(LinearLayout.VERTICAL);
        TextView tv = new TextView(this);
        tv.setText("This is a TextView");
        tv.setLayoutParams(params);
        
        Button btn = new Button(this);
        btn.setText("This is a Button");
        btn.setLayoutParams(params);
                        
        layout.addView(tv);
        layout.addView(btn);
        LinearLayout.LayoutParams layoutParam = 
            new LinearLayout.LayoutParams(
                    LayoutParams.FILL_PARENT,
                    LayoutParams.WRAP_CONTENT );
                       
        this.addContentView(layout, layoutParam);    
    }
}
//main.xml

    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="@string/hello"
    />