简单播放视频，使用摄像头拍照

1.要使用MediaPlayer播放视频，需要编写一个可以用于视频显示的空间，而这块空间要求可以快速进行GUI更新，而且可以在渲染代码时对GUI进行无阻塞的渲染，要实现该功能需要android.view.SurfaceView组件。SurfaceView组件封装了一个Surface对象，使用Surface可以完成对后台线程的控制，对于视频、3D图形等需要快速更新或者高帧率的对象有很大用处。
在SurfaceView类中，getHolder()方法最常用，该方法返回一个android.view.SurfaceHolder接口的实例化对象，使用SurfaceHolder接口可以控制显示的大小、像素等。
2.播放sdcard中的视频文件：

public class MyVideoPlayerDemo extends Activity {    private ImageButton play = null ;    private ImageButton stop = null ;    private MediaPlayer media = null ;    private SurfaceView surfaceView = null ;    private SurfaceHolder surfaceHolder = null ;    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        super.setContentView(R.layout.main);        this.play = (ImageButton) super.findViewById(R.id.play) ;        this.stop = (ImageButton) super.findViewById(R.id.stop) ;        this.surfaceView = (SurfaceView) super.findViewById(R.id.surfaceView) ;        this.surfaceHolder = this.surfaceView.getHolder() ;//取得SurfaceHolder//设置SurfaceView的类型        this.surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);        this.media = new MediaPlayer() ;//创建MediaPlayer对象        try {            this.media.setDataSource("/sdcard/mldn.3gp") ;  //设置播放文件的路径        } catch (Exception e) {            e.printStackTrace();        }        this.play.setOnClickListener(new PlayOnClickListenerImpl()) ;        this.stop.setOnClickListener(new StopOnClickListenerImpl()) ;    }    private class PlayOnClickListenerImpl implements OnClickListener {        @Override        public void onClick(View v) {        //设置音频类型    MyVideoPlayerDemo.this.media.setAudioStreamType(AudioManager.STREAM_MUSIC) ;        //设置显示区域    MyVideoPlayerDemo.this.media.setDisplay(MyVideoPlayerDemo.this.surfaceHolder) ;            try {                MyVideoPlayerDemo.this.media.prepare() ;//预备状态            } catch (Exception e) {            }            MyVideoPlayerDemo.this.media.start() ;//播放视频        }    }    private class StopOnClickListenerImpl implements OnClickListener {        @Override        public void onClick(View v) {            MyVideoPlayerDemo.this.media.stop() ;//停止播放        }    }}

使用摄像头拍照
1.想实现拍照功能，需要手工实现android.view.SurfaceHolder.Callback操作接口。调用摄像头的操作类android.hardware.Camera，此类主要负责完成拍照的参数设置及保存。
2.捕获图像：

public class MyCameraDemo extends Activity {    private SurfaceView surface = null ;    private Button but = null ;    private SurfaceHolder holder = null ;    private Camera cam = null ;    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        super.setContentView(R.layout.main);        this.but = (Button) super.findViewById(R.id.but) ;        this.surface = (SurfaceView) super.findViewById(R.id.surface) ;        this.holder = this.surface.getHolder() ;        this.holder.addCallback(new MySurfaceViewCallback()) ;        this.holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS) ;        this.holder.setFixedSize(800, 480);        this.but.setOnClickListener(new OnClickListenerImpl()) ;    }    private class OnClickListenerImpl implements OnClickListener {        @Override        public void onClick(View v) {        }    }    private class MySurfaceViewCallback implements SurfaceHolder.Callback {        @Override        public void surfaceChanged(SurfaceHolder holder, int format, int width,                int height) {        }        @Override        public void surfaceCreated(SurfaceHolder holder) {            MyCameraDemo.this.cam = Camera.open(0) ;    // 取得第一个摄像头            WindowManager manager = (WindowManager) MyCameraDemo.this                    .getSystemService(Context.WINDOW_SERVICE);            Display display = manager.getDefaultDisplay() ;            Parameters param = MyCameraDemo.this.cam.getParameters() ;            param.setPreviewSize(display.getWidth(), display.getHeight()) ;            param.setPreviewFrameRate(5) ;  // 一秒5帧            param.setPictureFormat(PixelFormat.JPEG) ;  // 图片形式            param.set("jpen-quality", 85) ;            MyCameraDemo.this.cam.setParameters(param) ;            try {                MyCameraDemo.this.cam.setPreviewDisplay(MyCameraDemo.this.holder) ;            } catch (IOException e) {            }            MyCameraDemo.this.cam.startPreview() ;  // 进行预览        }        @Override        public void surfaceDestroyed(SurfaceHolder holder) {        }    }}

3.实现拍照

public class MyCameraDemo extends Activity {    private SurfaceView surface = null ;//主要用于取得SurfaceHolder对象    private Button but = null ;    private SurfaceHolder holder = null ;//主要用来设置图片的类型、分辨率等参数以及//指定SurfaceHolder.Callback    private Camera cam = null ;//负责具体的拍照操作    private boolean previewRunning =  true ;//保存现在是否是预览状态    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        super.setContentView(R.layout.main);super.requestWindowFeature(Window.FEATURE_NO_TITLE);//不显示标题super.getWindow.setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN);//全屏显示super.getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);//高亮显示        this.but = (Button) super.findViewById(R.id.but) ;        this.surface = (SurfaceView) super.findViewById(R.id.surface) ;        this.holder = this.surface.getHolder() ;//调用Holder        this.holder.addCallback(new MySurfaceViewCallback()) ;//加入回调    this.holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS) ;//设置缓冲类型        this.holder.setFixedSize(500, 350);//设置分辨率        this.but.setOnClickListener(new OnClickListenerImpl()) ;    }    private class OnClickListenerImpl implements OnClickListener {        @Override        public void onClick(View v) {            if(MyCameraDemo.this.cam != null) {//存在Camera对象        MyCameraDemo.this.cam.autoFocus(new AutoFocusCallbackImpl()) ;//自动对焦            }        }    }    //接口SurfaceHolder.Callback被用来接收摄像头预览界面变化的信息    private class MySurfaceViewCallback implements SurfaceHolder.Callback {        @Override        public void surfaceChanged(SurfaceHolder holder, int format, int width,                int height) {//当预览界面的格式和大小发生改变时，该方法被调用        }        @Override        public void surfaceCreated(SurfaceHolder holder) {//初次实例化预览界面调用            MyCameraDemo.this.cam = Camera.open(0) ;    // 取得第一个摄像头            WindowManager manager = (WindowManager) MyCameraDemo.this                    .getSystemService(Context.WINDOW_SERVICE);//取得服务            Display display = manager.getDefaultDisplay() ;//取得Display对象        Parameters param = MyCameraDemo.this.cam.getParameters() ;//取得相机参数    param.setPreviewSize(display.getWidth(), display.getHeight()) ;//设置预览大小            param.setPreviewFrameRate(5) ;  // 一秒5帧            param.setPictureFormat(PixelFormat.JPEG) ;  // 图片形式            param.set("jpen-quality", 80) ;//设置图片质量，最高为100            MyCameraDemo.this.cam.setParameters(param) ;//设置参数            try {//通过SurfaceView显示                MyCameraDemo.this.cam.setPreviewDisplay(MyCameraDemo.this.holder) ;            } catch (IOException e) {            }            MyCameraDemo.this.cam.startPreview() ;  // 进行预览            MyCameraDemo.this.previewRunning = true ;   // 修改预览标记，已经开始预览        }        @Overridepublic void surfaceDestroyed(SurfaceHolder holder) {//当预览界面被关闭时方法被调用            if(MyCameraDemo.this.cam != null) {                if(MyCameraDemo.this.previewRunning) {//如果正在预览                    MyCameraDemo.this.cam.stopPreview() ;   // 停止预览                    MyCameraDemo.this.previewRunning = false ;//修改标记                }//摄像头只能被一个Activity程序使用，所有要释放摄像头                MyCameraDemo.this.cam.release() ;//释放摄像头            }        }    }    private class AutoFocusCallbackImpl implements AutoFocusCallback {        @Override        public void onAutoFocus(boolean success, Camera camera) {            if(success) {   // 对焦成功                MyCameraDemo.this.cam.takePicture(sc, pc, jpgcall) ;//获取图片MyCameraDemo.this.cam.stopPreview();//停止预览            }        }    }    private PictureCallback jpgcall = new PictureCallback() {        @Override        public void onPictureTaken(byte[] data, Camera camera) {    // 保存图片的操作            Bitmap bmp = BitmapFactory.decodeByteArray(data, 0, data.length);            String fileName = Environment.getExternalStorageDirectory()                    .toString()                    + File.separator                    + "mldnphoto"                    + File.separator                    + "MLDN_" + System.currentTimeMillis() + ".jpg";//输出文件名称            File file = new File(fileName) ;//定义File对象            if (!file.getParentFile().exists()) {//父文件夹不存在                file.getParentFile().mkdirs() ; // 创建文件夹            }            try {                BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(file)) ;//使用字节缓存流                bmp.compress(Bitmap.CompressFormat.JPEG, 80, bos) ; // 向缓冲区之中压缩图片                bos.flush() ;//清空缓存                bos.close() ;//关闭                Toast.makeText(MyCameraDemo.this,                        "拍照成功，照片已保存在" + fileName + "文件之中！", Toast.LENGTH_SHORT)                        .show();//显示Toast            } catch (Exception e) {                Toast.makeText(MyCameraDemo.this,                        "拍照失败！", Toast.LENGTH_SHORT)                        .show();            }            MyCameraDemo.this.cam.stopPreview() ;//停止预览            MyCameraDemo.this.cam.startPreview() ;//开始预览        }    } ;    private ShutterCallback sc = new ShutterCallback(){        @Override        public void onShutter() {            // 按下快门之后进行的操作        }    } ;    private PictureCallback pc = new PictureCallback() {        @Override        public void onPictureTaken(byte[] data, Camera camera) {            //保存的源图片数据        }    } ;}

配置权限文件：

<uses-feature android:name="android.hardware.camera" />    <uses-feature android:name="android.hardware.camera.autofocus" />    <uses-permission android:name="android.permission.CAMERA" />    <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" />    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />