<?xml version="1.0" encoding="utf-8"?>

<manifest xmlns:android="http://schemas.android.com/apk/res/android"

    package="com.hanqi.test6">

    <application

        android:allowBackup="true"

        android:icon="@mipmap/ic_launcher"

        android:label="@string/app_name"

        android:supportsRtl="true"

        android:theme="@style/AppTheme">

        <activity android:name=".Activity1">

        </activity>

        <activity android:name=".MainActivity">

            <intent-filter>

                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />

            </intent-filter>

        </activity>

    </application>

</manifest>

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout 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"

    tools:context="com.hanqi.test6.MainActivity"

    android:orientation="vertical"><!--orientation改方向   vertical垂直-->

    <Button

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="按钮一"

        />

    <Button

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="按钮二"

        android:id="@+id/button2"

        />

</LinearLayout>

package com.hanqi.test6;

import android.support.v7.app.AppCompatActivity;

import android.os.Bundle;

import android.widget.Button;

public class MainActivity extends AppCompatActivity {

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        //获取文件findViewById

        Button button2 = (Button)findViewById(R.id.button2);

        //设置setText

        button2.setText("新按钮名");

    }

}

package com.hanqi.test6;

import android.os.Bundle;

import android.support.v4.widget.DrawerLayout;

import android.support.v7.app.AppCompatActivity;

import android.view.ViewGroup;

import android.widget.Button;

import android.widget.LinearLayout;

/**

 * Created by Administrator on 2016/3/22.

 */

public class Activity1 extends AppCompatActivity {

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        //创建布局管理器  LinearLayout线性布局

        LinearLayout linearLayout = new LinearLayout(this);

        //setOrientation 布局方向   VERTICAL垂直

        linearLayout.setOrientation(LinearLayout.VERTICAL);

        //setLayoutParams属性   创建属性集合

        linearLayout.setLayoutParams(

                new DrawerLayout.LayoutParams(

                        ViewGroup.LayoutParams.MATCH_PARENT,

                        ViewGroup.LayoutParams.MATCH_PARENT));

        Button button = new Button(this);

        //设置显示的内容

        button.setText("按钮二");

        //setLayoutParams属性   创建属性集合

        button.setLayoutParams(

                new DrawerLayout.LayoutParams(

                    ViewGroup.LayoutParams.WRAP_CONTENT,

                    ViewGroup.LayoutParams.WRAP_CONTENT));

        //把View放到布局里去   addView添加布局

        linearLayout.addView(button);

        button.setText("按钮三");

        //setLayoutParams属性   创建属性集合

        button.setLayoutParams(

                new DrawerLayout.LayoutParams(

                        ViewGroup.LayoutParams.WRAP_CONTENT,

                        ViewGroup.LayoutParams.WRAP_CONTENT));

        //把View放到布局里去   addView添加布局

        linearLayout.addView(button);

        //关联布局管理器  setContentView关联

        setContentView(linearLayout);

    }

}