（五）使用代码创建UI

 1 package com.example.codeUI;
 2 
 3 import android.app.Activity;
 4 import android.os.Bundle;
 5 import android.view.Gravity;
 6 import android.widget.LinearLayout;
 7 import android.widget.TextView;
 8 
 9 public class MainActivity extends Activity {
10 
11     @Override
12     protected void onCreate(Bundle savedInstanceState) {
13         super.onCreate(savedInstanceState);
14         LinearLayout  ll=new LinearLayout(this);
15         ll.setGravity(Gravity.CENTER);
16         TextView tv=new TextView(this);
17         tv.setTextSize(20.0f);
18         tv.setText("江西");
19         ll.addView(tv);
20         setContentView(ll);
21      }
22 }