22_Android中的本地音乐播放器和网络音乐播放器的编写，本地视频播放器和网络视频播放器，照相机案例，偷拍案例实现

1 编写以下案例：

当点击了”播放”之后，在手机上的/mnt/sdcard2/natural.mp3就会播放。

2 编写布局文件activity_main.xml

<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"

android:orientation="vertical"

tools:context=".MainActivity" >

<EditText

android:id="@+id/et_path"

android:layout_width="fill_parent"

android:layout_height="wrap_content"

        android:hint="请输入要播放文件的路径" />

<LinearLayout

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:orientation="horizontal" >

<Button

android:id="@+id/bt_play"

android:onClick="play"

android:layout_width="0dip"

android:layout_height="wrap_content"

android:layout_weight="1"

            android:text="播放" />

<Button

android:id="@+id/bt_pause"

android:onClick="pause"

android:layout_width="0dip"

android:layout_height="wrap_content"

android:layout_weight="1"

            android:text="暂停" />

<Button

android:id="@+id/bt_stop"

android:onClick="stop"

android:layout_width="0dip"

android:layout_height="wrap_content"

android:layout_weight="1"

            android:text="停止" />

<Button

android:id="@+id/bt_replay"

android:onClick="replay"

android:layout_width="0dip"

android:layout_height="wrap_content"

android:layout_weight="1"

            android:text="重播" />

</LinearLayout>

</LinearLayout>

3 编写MainActivity

package com.itheima.musicplayer;

import java.io.File;

import java.io.IOException;

import android.app.Activity;

import android.media.AudioManager;

import android.media.MediaPlayer;

import android.media.MediaPlayer.OnCompletionListener;

import android.os.Bundle;

import android.view.View;

import android.widget.Button;

import android.widget.EditText;

import android.widget.Toast;

public class MainActivity extends Activity {

private EditText et_path;

private MediaPlayer mediaPlayer;

private Button bt_play,bt_pause,bt_stop,bt_replay;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

et_path = (EditText) findViewById(R.id.et_path);

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

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

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

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

}

/**

* 播放

* @param view

*/

public void play(View view) {

String filepath = et_path.getText().toString().trim();

File file = new File(filepath);

if(file.exists()){

try {

mediaPlayer = new MediaPlayer();

mediaPlayer.setDataSource(filepath);//设置播放的数据源。

mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);

mediaPlayer.prepare();//准备开始播放 播放的逻辑是c代码在新的线程里面执行。

mediaPlayer.start();

bt_play.setEnabled(false);

mediaPlayer.setOnCompletionListener(new OnCompletionListener() {

@Override

public void onCompletion(MediaPlayer mp) {

bt_play.setEnabled(true);

}

});

} catch (Exception e) {

e.printStackTrace();

Toast.makeText(this, "播放失败", 0).show();

}

}else{

Toast.makeText(this, "文件不存在，请检查文件的路径", 0).show();

}

}

/**

* 暂停

* @param view

*/

public void pause(View view) {

if("继续".equals(bt_pause.getText().toString())){

mediaPlayer.start();

bt_pause.setText("暂停");

return;

}

if(mediaPlayer!=null&&mediaPlayer.isPlaying()){

//这里表示的是暂停功能

mediaPlayer.pause();

bt_pause.setText("继续");

}

}

/**

* 停止

* @param view

*/

public void stop(View view) {

if(mediaPlayer!=null&&mediaPlayer.isPlaying()){

//通过stop方法停止播放音乐

mediaPlayer.stop();

mediaPlayer.release();

mediaPlayer = null;

}

bt_pause.setText("暂停");

bt_play.setEnabled(true);

}

/**

* 重播

* @param view

*/

public void replay(View view) {

if(mediaPlayer!=null&&mediaPlayer.isPlaying()){

//通过seekTo方法指定到某个位置播放音乐

mediaPlayer.seekTo(0);

}else{

play(view);

}

bt_pause.setText("暂停");

}

}

如果想播放网络上的音乐，需要把上面的play代码改成：

/**

* 播放

*

* @param view

*/

public void play(View view) {

String filepath = et_path.getText().toString().trim();

// http://

if (filepath.startsWith("http://")) {

try {

mediaPlayer = new MediaPlayer();

mediaPlayer.setDataSource(filepath);// 设置播放的数据源。

mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);

// mediaPlayer.prepare();//同步的准备方法。

mediaPlayer.prepareAsync();// 异步的准备

mediaPlayer.setOnPreparedListener(new OnPreparedListener() {

@Override

public void onPrepared(MediaPlayer mp) {

mediaPlayer.start();

bt_play.setEnabled(false);

}

});

mediaPlayer.setOnCompletionListener(new OnCompletionListener() {

@Override

public void onCompletion(MediaPlayer mp) {

bt_play.setEnabled(true);

}

});

} catch (Exception e) {

e.printStackTrace();

Toast.makeText(this, "播放失败", 0).show();

}

        } else {

Toast.makeText(this, "请检查文件的路径", 0).show();

}

}

==============================================================================

1. 视频播放器，实现”播放”、“暂停”、”停止”、“重播”。案例截图如下：

2. 

1. 播放布局文件

<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"

android:orientation="vertical"

tools:context=".MainActivity" >

<EditText

android:id="@+id/et_path"

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:hint="请输入要播放文件的路径" />

<SeekBar

android:id="@+id/seekBar1"

android:layout_width="match_parent"

android:layout_height="wrap_content" />

<LinearLayout

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:orientation="horizontal" >

<Button

android:id="@+id/bt_play"

android:layout_width="0dip"

android:layout_height="wrap_content"

android:layout_weight="1"

android:onClick="play"

android:text="播放" />

<Button

android:id="@+id/bt_pause"

android:layout_width="0dip"

android:layout_height="wrap_content"

android:layout_weight="1"

android:onClick="pause"

android:text="暂停" />

<Button

android:id="@+id/bt_stop"

android:layout_width="0dip"

android:layout_height="wrap_content"

android:layout_weight="1"

android:onClick="stop"

android:text="停止" />

<Button

android:id="@+id/bt_replay"

android:layout_width="0dip"

android:layout_height="wrap_content"

android:layout_weight="1"

android:onClick="replay"

android:text="重播" />

</LinearLayout>

<SurfaceView

android:id="@+id/sv"

android:layout_width="fill_parent"

android:layout_height="fill_parent" />

</LinearLayout>

1. 编写MainActivity，代码如下：

package com.itheima.musicplayer;

import java.io.File;

import java.io.IOException;

import java.util.Timer;

import java.util.TimerTask;

import android.app.Activity;

import android.media.AudioManager;

import android.media.MediaPlayer;

import android.media.MediaPlayer.OnCompletionListener;

import android.os.Bundle;

import android.view.SurfaceHolder;

import android.view.SurfaceHolder.Callback;

import android.view.SurfaceView;

import android.view.View;

import android.widget.Button;

import android.widget.EditText;

import android.widget.SeekBar;

import android.widget.SeekBar.OnSeekBarChangeListener;

import android.widget.Toast;

public class MainActivity extends Activity {

private EditText et_path;

private MediaPlayer mediaPlayer;

private Button bt_play,bt_pause,bt_stop,bt_replay;

private SurfaceView sv;

private SurfaceHolder holder;

private int position;

private String filepath;

private SeekBar seekBar1;

private Timer timer;

private TimerTask task;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

et_path = (EditText) findViewById(R.id.et_path);

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

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

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

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

seekBar1 = (SeekBar) findViewById(R.id.seekBar1);

seekBar1.setOnSeekBarChangeListener(new OnSeekBarChangeListener() {

@Override

public void onStopTrackingTouch(SeekBar seekBar) {

int postion = seekBar.getProgress();

mediaPlayer.seekTo(postion);

}

@Override

public void onStartTrackingTouch(SeekBar seekBar) {

}

@Override

public void onProgressChanged(SeekBar seekBar, int progress,

boolean fromUser) {

}

});

//得到surfaceview

sv = (SurfaceView) findViewById(R.id.sv);

//得到显示界面内容的容器

holder = sv.getHolder();

//在低版本模拟器上运行记得加上下面的参数。不自己维护双缓冲区，而是等待多媒体播放框架主动的推送数据。

holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);

holder.addCallback(new Callback() {

@Override

public void surfaceDestroyed(SurfaceHolder holder) {

System.out.println("destoryed");

if(mediaPlayer!=null&&mediaPlayer.isPlaying()){

position = mediaPlayer.getCurrentPosition();

mediaPlayer.stop();

mediaPlayer.release();

mediaPlayer = null;

timer.cancel();

task.cancel();

timer = null;

task = null;

}

}

@Override

public void surfaceCreated(SurfaceHolder holder) {

System.out.println("created");

if(position>0){//记录的有播放进度。

try {

mediaPlayer = new MediaPlayer();

mediaPlayer.setDataSource(filepath);//设置播放的数据源。

mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);

mediaPlayer.setDisplay(holder);

mediaPlayer.prepare();//准备开始播放 播放的逻辑是c代码在新的线程里面执行。

mediaPlayer.start();

mediaPlayer.seekTo(position);

bt_play.setEnabled(false);

mediaPlayer.setOnCompletionListener(new OnCompletionListener() {

@Override

public void onCompletion(MediaPlayer mp) {

bt_play.setEnabled(true);

}

});

int max = mediaPlayer.getDuration();

seekBar1.setMax(max);

timer = new Timer();

task = new TimerTask() {

@Override

public void run() {

seekBar1.setProgress(mediaPlayer.getCurrentPosition());

}

};

timer.schedule(task, 0, 500);

} catch (IOException e) {

e.printStackTrace();

}

}

}

@Override

public void surfaceChanged(SurfaceHolder holder, int format, int width,

int height) {

System.out.println("changed");

}

});

}

/**

* 播放

* @param view

*/

public void play(View view) {

filepath = et_path.getText().toString().trim();

File file = new File(filepath);

if(file.exists()){

try {

mediaPlayer = new MediaPlayer();

mediaPlayer.setDataSource(filepath);//设置播放的数据源。

mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);

mediaPlayer.setDisplay(holder);

mediaPlayer.prepare();//准备开始播放 播放的逻辑是c代码在新的线程里面执行。

mediaPlayer.start();

//设置拖动进度条的最大值

int max = mediaPlayer.getDuration();

seekBar1.setMax(max);

timer = new Timer();

task = new TimerTask() {

@Override

public void run() {

seekBar1.setProgress(mediaPlayer.getCurrentPosition());

}

};

timer.schedule(task, 0, 500);

bt_play.setEnabled(false);

mediaPlayer.setOnCompletionListener(new OnCompletionListener() {

@Override

public void onCompletion(MediaPlayer mp) {

bt_play.setEnabled(true);

}

});

} catch (Exception e) {

e.printStackTrace();

Toast.makeText(this, "播放失败", 0).show();

}

}else{

Toast.makeText(this, "文件不存在，请检查文件的路径", 0).show();

}

}

/**

* 暂停

* @param view

*/

public void pause(View view) {

if("继续".equals(bt_pause.getText().toString())){

mediaPlayer.start();

bt_pause.setText("暂停");

return;

}

if(mediaPlayer!=null&&mediaPlayer.isPlaying()){

mediaPlayer.pause();

bt_pause.setText("继续");

}

}

/**

* 停止

* @param view

*/

public void stop(View view) {

if(mediaPlayer!=null&&mediaPlayer.isPlaying()){

mediaPlayer.stop();

mediaPlayer.release();

mediaPlayer = null;

}

bt_pause.setText("暂停");

bt_play.setEnabled(true);

}

/**

* 重播

* @param view

*/

public void replay(View view) {

if(mediaPlayer!=null&&mediaPlayer.isPlaying()){

mediaPlayer.seekTo(0);

}else{

play(view);

}

bt_pause.setText("暂停");

}

}

网络视频播放器，编写布局文件

<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"

android:orientation="vertical"

tools:context=".MainActivity" >

<EditText

android:id="@+id/et_path"

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:hint="请输入要播放文件的路径"/>

<LinearLayout

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:orientation="horizontal" >

<Button

android:id="@+id/bt_play"

android:layout_width="0dip"

android:layout_height="wrap_content"

android:layout_weight="1"

android:onClick="play"

android:text="播放" />

<Button

android:id="@+id/bt_pause"

android:layout_width="0dip"

android:layout_height="wrap_content"

android:layout_weight="1"

android:onClick="pause"

android:text="暂停" />

<Button

android:id="@+id/bt_stop"

android:layout_width="0dip"

android:layout_height="wrap_content"

android:layout_weight="1"

android:onClick="stop"

android:text="停止" />

<Button

android:id="@+id/bt_replay"

android:layout_width="0dip"

android:layout_height="wrap_content"

android:layout_weight="1"

android:onClick="replay"

android:text="重播" />

</LinearLayout>

<SurfaceView

android:id="@+id/sv"

android:layout_width="fill_parent"

android:layout_height="fill_parent" />

</LinearLayout>

编写MainActivity

package com.itheima.musicplayer;

import java.io.File;

import java.io.IOException;

import android.app.Activity;

import android.media.AudioManager;

import android.media.MediaPlayer;

import android.media.MediaPlayer.OnCompletionListener;

import android.os.Bundle;

import android.view.SurfaceHolder;

import android.view.SurfaceHolder.Callback;

import android.view.SurfaceView;

import android.view.View;

import android.widget.Button;

import android.widget.EditText;

import android.widget.Toast;

public class MainActivity extends Activity {

private EditText et_path;

private MediaPlayer mediaPlayer;

private Button bt_play,bt_pause,bt_stop,bt_replay;

private SurfaceView sv;

private SurfaceHolder holder;

private int position;

private String filepath;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

et_path = (EditText) findViewById(R.id.et_path);

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

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

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

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

//得到surfaceview

sv = (SurfaceView) findViewById(R.id.sv);

//得到显示界面内容的容器

holder = sv.getHolder();

//在低版本模拟器上运行记得加上下面的参数。不自己维护双缓冲区，而是等待多媒体播放框架主动的推送数据。

holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);

holder.addCallback(new Callback() {

@Override

public void surfaceDestroyed(SurfaceHolder holder) {

System.out.println("destoryed");

if(mediaPlayer!=null&&mediaPlayer.isPlaying()){

position = mediaPlayer.getCurrentPosition();

mediaPlayer.stop();

mediaPlayer.release();

mediaPlayer = null;

}

}

@Override

public void surfaceCreated(SurfaceHolder holder) {

System.out.println("created");

if(position>0){//记录的有播放进度。

try {

mediaPlayer = new MediaPlayer();

mediaPlayer.setDataSource(filepath);//设置播放的数据源。

mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);

mediaPlayer.setDisplay(holder);

mediaPlayer.prepare();//准备开始播放 播放的逻辑是c代码在新的线程里面执行。

mediaPlayer.start();

mediaPlayer.seekTo(position);

bt_play.setEnabled(false);

mediaPlayer.setOnCompletionListener(new OnCompletionListener() {

@Override

public void onCompletion(MediaPlayer mp) {

bt_play.setEnabled(true);

}

});

} catch (IOException e) {

e.printStackTrace();

}

}

}

@Override

public void surfaceChanged(SurfaceHolder holder, int format, int width,

int height) {

System.out.println("changed");

}

});

}

/**

* 播放

* @param view

*/

public void play(View view) {

filepath = et_path.getText().toString().trim();

//File file = new File(filepath);

if(filepath.startsWith("http://")){

try {

mediaPlayer = new MediaPlayer();

mediaPlayer.setDataSource(filepath);//设置播放的数据源。

mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);

mediaPlayer.setDisplay(holder);

mediaPlayer.prepare();//准备开始播放 播放的逻辑是c代码在新的线程里面执行。

mediaPlayer.start();

bt_play.setEnabled(false);

mediaPlayer.setOnCompletionListener(new OnCompletionListener() {

@Override

public void onCompletion(MediaPlayer mp) {

bt_play.setEnabled(true);

}

});

} catch (Exception e) {

e.printStackTrace();

Toast.makeText(this, "播放失败", 0).show();

}

}else{

Toast.makeText(this, "文件不存在，请检查文件的路径", 0).show();

}

}

/**

* 暂停

* @param view

*/

public void pause(View view) {

if("继续".equals(bt_pause.getText().toString())){

mediaPlayer.start();

bt_pause.setText("暂停");

return;

}

if(mediaPlayer!=null&&mediaPlayer.isPlaying()){

mediaPlayer.pause();

bt_pause.setText("继续");

}

}

/**

* 停止

* @param view

*/

public void stop(View view) {

if(mediaPlayer!=null&&mediaPlayer.isPlaying()){

mediaPlayer.stop();

mediaPlayer.release();

mediaPlayer = null;

}

bt_pause.setText("暂停");

bt_play.setEnabled(true);

}

/**

* 重播

* @param view

*/

public void replay(View view) {

if(mediaPlayer!=null&&mediaPlayer.isPlaying()){

mediaPlayer.seekTo(0);

}else{

play(view);

}

bt_pause.setText("暂停");

}

}

AndroidManifest.xml

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

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

package="com.itheima.musicplayer"

android:versionCode="1"

android:versionName="1.0" >

<uses-sdk

android:minSdkVersion="8"

android:targetSdkVersion="19" />

<!-- 注意如果涉及到网络的都要添加上下面的一句 -->

<uses-permission android:name="android.permission.INTERNET"/>

<application

android:allowBackup="true"

android:icon="@drawable/ic_launcher"

android:label="@string/app_name"

android:theme="@style/AppTheme" >

<activity

android:name="com.itheima.musicplayer.MainActivity"

android:label="@string/app_name" >

<intent-filter>

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

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

</intent-filter>

</activity>

</application>

</manifest>

照相机引用，如果想使用模拟器进行拍照，需要制定模拟器的一个设置，设置如下图：

编写以下案例，当点击”拍照”之后弹出权限提示框。

1 编写布局文件activity_main.xml，代码如下：

<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"

android:orientation="vertical"

tools:context=".MainActivity" >

<Button

android:onClick="click"

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:text="拍照" />

<ImageView

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:id="@+id/iv"/>

</LinearLayout>

1 MainActivity的代码如下：

package com.itheima.camera;

import java.io.File;

import android.app.Activity;

import android.content.Intent;

import android.net.Uri;

import android.os.Bundle;

import android.os.Environment;

import android.provider.MediaStore;

import android.util.Log;

import android.view.View;

import android.widget.ImageView;

/**

* 拍照的实例代码

* @author toto

*/

public class MainActivity extends Activity {

private ImageView iv;

private File file;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

iv = (ImageView) findViewById(R.id.iv);

}

/**

* 当点击之后的效果

* @param view

*/

public void click(View view) {

Intent intent = new Intent();

//指定拍照的意图ACTION_IMAGE_CAPTURE,如果是录像的可以用ACTION_VIDEO_CAPTURE,并且将文件后缀改成.3gp

intent.setAction(MediaStore.ACTION_IMAGE_CAPTURE);

Log.i("FILE-PATH", Environment.getExternalStorageDirectory().toString());

//第一个参数是文件路径，第二个参数表示的是文件名称

file =  new File(Environment.getExternalStorageDirectory(),System.currentTimeMillis()+".jpg");

//指定保存文件的路径

intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(file));

//开启一个新的action，并且获得其返回值

startActivityForResult(intent, 100);

}

/**

* 当startActivityForResult返回结果的时候会执行下面的函数

*/

@Override

protected void onActivityResult(int requestCode, int resultCode, Intent data) {

if (resultCode == 100) {

iv.setImageURI(Uri.fromFile(file));

}

super.onActivityResult(requestCode, resultCode, data);

}

}

若是手机，例如我的手机，存储在/sdcard/emulated/0中。

===============================================================================

偷拍的案例，编写如下案例（将下面的图片显示区域变得很小可以实现偷拍功能）：

1 编写布局文件activity_main.xml

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

xmlns:tools="http://schemas.android.com/tools"

android:layout_width="match_parent"

android:orientation="vertical"

android:layout_height="match_parent"

tools:context=".MainActivity" >

<Button

android:onClick="click"

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:text="拍照"/>

<FrameLayout

android:id="@+id/camera_preview"

android:layout_width="100dip"

android:layout_height="100dip"/>

<ImageView

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:id="@+id/iv"/>

</LinearLayout>

2 CameraPreview的代码如下：

package com.itheima.camera2;

import java.io.IOException;

import android.content.Context;

import android.hardware.Camera;

import android.util.Log;

import android.view.SurfaceHolder;

import android.view.SurfaceView;

/** A basic Camera preview class */

public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback {

private static final String TAG = "CameraPreview";

private SurfaceHolder mHolder;

private Camera mCamera;

@SuppressWarnings("deprecation")

public CameraPreview(Context context, Camera camera) {

super(context);

mCamera = camera;

// Install a SurfaceHolder.Callback so we get notified when the

// underlying surface is created and destroyed.

mHolder = getHolder();

mHolder.addCallback(this);

// deprecated setting, but required on Android versions prior to 3.0

mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);

}

public void surfaceCreated(SurfaceHolder holder) {

// The Surface has been created, now tell the camera where to draw the preview.

try {

mCamera.setPreviewDisplay(holder);

mCamera.startPreview();

} catch (IOException e) {

Log.d(TAG, "Error setting camera preview: " + e.getMessage());

}

}

public void surfaceDestroyed(SurfaceHolder holder) {

// empty. Take care of releasing the Camera preview in your activity.

}

public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {

// If your preview can change or rotate, take care of those events here.

// Make sure to stop the preview before resizing or reformatting it.

if (mHolder.getSurface() == null){

// preview surface does not exist

return;

}

// stop preview before making changes

try {

mCamera.stopPreview();

} catch (Exception e){

// ignore: tried to stop a non-existent preview

}

// set preview size and make any resize, rotate or

// reformatting changes here

// start preview with new settings

try {

mCamera.setPreviewDisplay(mHolder);

mCamera.startPreview();

} catch (Exception e){

Log.d(TAG, "Error starting camera preview: " + e.getMessage());

}

}

}

1. MainActivity的代码如下：

package com.itheima.camera2;

import java.io.File;

import java.io.FileOutputStream;

import android.app.Activity;

import android.hardware.Camera;

import android.hardware.Camera.AutoFocusCallback;

import android.hardware.Camera.PictureCallback;

import android.os.Bundle;

import android.os.SystemClock;

import android.view.View;

import android.widget.FrameLayout;

import android.widget.ImageView;

import android.widget.Toast;

public class MainActivity extends Activity {

private ImageView iv;

private Camera mCamera;

private CameraPreview mPreview;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

iv = (ImageView) findViewById(R.id.iv);

// Create an instance of Camera

mCamera = getCameraInstance();

// Create our Preview view and set it as the content of our activity.

mPreview = new CameraPreview(this, mCamera);

FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview);

preview.addView(mPreview);

}

public void click(View view){

mCamera.autoFocus(new AutoFocusCallback() {

@Override

public void onAutoFocus(boolean success, Camera camera) {

mCamera.takePicture(null, null, new PictureCallback() {

@Override

public void onPictureTaken(byte[] data, Camera camera) {

try {

//File file = new File(Environment.getExternalStorageDirectory(),SystemClock.uptimeMillis()+".jpg");

File file = new File("/mnt/sdcard2",SystemClock.uptimeMillis()+".jpg");

FileOutputStream fos = new FileOutputStream(file);

fos.write(data);

fos.close();

Toast.makeText(getApplicationContext(), "成功", 0).show();

mCamera.startPreview();

} catch (Exception e) {

e.printStackTrace();

}

}

});

}

});

}

/** 获取一个照相机实例 */

public static Camera getCameraInstance(){

Camera c = null;

try {

c = Camera.open(); // attempt to get a Camera instance

}

catch (Exception e){

// Camera is not available (in use or does not exist)

}

return c; // returns null if camera is unavailable

}

@Override

protected void onDestroy() {

mCamera.stopPreview();

mCamera.release();

mCamera = null;

super.onDestroy();

}

}

1. 编写AndroidManifest.xml的清单文件，代码如下：

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

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

package="com.itheima.camera2"

android:versionCode="1"

android:versionName="1.0" >

<uses-sdk

android:minSdkVersion="8"

android:targetSdkVersion="19" />

<uses-permission android:name="android.permission.CAMERA" />

<uses-feature android:name="android.hardware.camera" />

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

<application

android:allowBackup="true"

android:icon="@drawable/ic_launcher"

android:label="@string/app_name"

android:theme="@style/AppTheme" >

<activity

android:name="com.itheima.camera2.MainActivity"

android:label="@string/app_name" >

<intent-filter>

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

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

</intent-filter>

</activity>

</application>

</manifest>