<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >
    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="64dp"
        android:text="添加" />
    <EditText
        android:id="@+id/editText1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:ems="10" >
        <requestFocus />
    </EditText>
</RelativeLayout>

package com.example.codeui;
import android.os.Bundle;
import android.app.Activity;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.View;
import android.view.ViewGroup;
import android.widget.LinearLayout;
import android.widget.TextView;
public class MainActivity extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        LinearLayout layout=new LinearLayout(this);
        layout.setOrientation(LinearLayout.VERTICAL);//显示方向
        //将view对象添加到布局界面
        TextView textView =new TextView(this);
        textView.setText("Hello Code UI");
        ViewGroup.LayoutParams params = new ViewGroup.LayoutParams(
                ViewGroup.LayoutParams.FILL_PARENT,ViewGroup.LayoutParams.WRAP_CONTENT);
        //添加
        layout.addView(textView,params);
        //添加外部xml定义的布局
        View view = getPartView();
        layout.addView(view);  
        ViewGroup.LayoutParams layoutParams = new ViewGroup.LayoutParams(
                ViewGroup.LayoutParams.FILL_PARENT,ViewGroup.LayoutParams.FILL_PARENT);
        setContentView(layout, layoutParams);
        //setContentView(R.layout.activity_main);
        //采用代码编写效率高，但是很难维护
    }
    //通过加载xml文件将view添加到布局中
    public View getPartView() {
        //将xml布局文件生成view对象通过LayoutInflater
        LayoutInflater inflater =(LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        //将view对象挂载到那个父元素上，这里没有就为null
        return inflater.inflate(R.layout.part, null);
    }
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }
}