android 摄像头的调用

这几天一直在看关于android调用摄像头的事情。其中一种是直接调用系统的摄像头，还有就是利用camera api来实现摄像头的调用。
（1） 直接调用系统的摄像头：主要就是这三句话：
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
intent.putExtra(MediaStore.EXTRA_OUTPUT,uri);
startActivityForResult(intent,SystemCapture);

public class MainActivity extends Activity {    private Button button;//拍摄按钮    protected int SystemCapture;    private ImageView imageView;    String imgPath = "/storage/sdcard0/mahc/image/img.jpg";    //固定的存储文件的路径    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        button = (Button)findViewById(R.id.button);        imageView = (ImageView)findViewById(R.id.imageView1);        button.setOnClickListener(new OnClickListener() {            @Override            public void onClick(View v) {                // TODO Auto-generated method stub                File file = new File(imgPath);                //如果文件不存在，则会自动创建文件用于存错照片，但是当这张照片有了之后，就不能进行存储别的照片了（）                if(!file.exists()){                    File vFile = file.getParentFile();                    vFile.mkdirs();                    Uri uri = Uri.fromFile(vFile);                    Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);                    intent.putExtra(MediaStore.EXTRA_OUTPUT, uri);                    //startActivityForResult(intent, CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE);                    startActivityForResult(intent, SystemCapture);            }        }        });    }//重载onActivityResult()函数，用于当在次进行拍照的时候显示前一次拍摄的照片的内容。    @Override    protected void onActivityResult(int requestCode, int resultCode, Intent data) {        // TODO Auto-generated method stub        super.onActivityResult(requestCode, resultCode, data);        if(resultCode == RESULT_OK){            imageView.setImageURI(Uri.fromFile(new File(imgPath)));        }    }    @Override    public boolean onCreateOptionsMenu(Menu menu) {        // Inflate the menu; this adds items to the action bar if it is present.        getMenuInflater().inflate(R.menu.main, menu);        return true;    }    @Override    public boolean onOptionsItemSelected(MenuItem item) {        // Handle action bar item clicks here. The action bar will        // automatically handle clicks on the Home/Up button, so long        // as you specify a parent activity in AndroidManifest.xml.        int id = item.getItemId();        if (id == R.id.action_settings) {            return true;        }        return super.onOptionsItemSelected(item);    }}

（2 ）调用camera api，自己实现拍照功能。
主要就是预览，拍照，然后在回到预览。
主要用到的有控件有surfaceView ,surfaceHolder，
主要代码为：
.xml文件：

<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:background="#FFFFFF"    tools:context=".CameraActivity" >    <LinearLayout        android:layout_width="match_parent"        android:layout_height="match_parent" >        <SurfaceView            android:id="@+id/camera_preview"            android:layout_width="match_parent"            android:layout_height="match_parent"            android:layout_gravity="center_vertical|center_horizontal" />    </LinearLayout>    <LinearLayout        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:layout_alignParentBottom="true">        <Button            android:id="@+id/camera_save"            android:layout_width="match_parent"            android:layout_height="wrap_content"            android:text="拍照" />    </LinearLayout></RelativeLayout>

主要的实现代码：

public class CameraActivity01 extends Activity{    private SurfaceView surfaceView;//用于预览时显示    private Button saveButton;//拍摄按钮    private Camera camera;    private SurfaceHolder surfaceHolder;//容器    @Override    protected void onCreate(Bundle savedInstanceState) {        // TODO Auto-generated method stub        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_camera);        saveButton = (Button)findViewById(R.id.camera_save);        surfaceView = (SurfaceView)findViewById(R.id.camera_preview);        //访问surfaceView的底层图形是通过surfaceHolder接口来实现的，通过getHolder（）方法可以得到这个surfaceHolder对象        surfaceHolder = surfaceView.getHolder();        //通过surfaceHolder.addCallback()方法来实现图像的预览与修改        surfaceHolder.addCallback(callback);        //进行点击事件的监听        saveButton.setOnClickListener(new OnClickListener() {            @Override            public void onClick(View view) {                // TODO Auto-generated method stub                //进行拍摄                camera.takePicture(null, null, pictureCallback);            }        });    }    SurfaceHolder.Callback callback = new SurfaceHolder.Callback() {        @Override        public void surfaceDestroyed(SurfaceHolder surfaceholder) {            // TODO Auto-generated method stub            //停止预览，释放camera            camera.stopPreview();            camera.release();            camera = null;        }        @Override        public void surfaceCreated(SurfaceHolder surfaceholder) {            // TODO Auto-generated method stub            //打开摄像头准备进行预。            camera = Camera.open();            try {            } catch (Exception e) {                // TODO: handle exception                camera.release();                camera = null;            }        }        @Override        public void surfaceChanged(SurfaceHolder surfaceholder, int i, int j, int k) {            // TODO Auto-generated method stub            //对摄像头进行参数的设置。            Camera.Parameters parameters = camera.getParameters();            parameters.setPictureFormat(ImageFormat.JPEG);            camera.setParameters(parameters);            try {                camera.setPreviewDisplay(surfaceholder);            } catch (IOException e) {                // TODO Auto-generated catch block                e.printStackTrace();                camera.release();                camera = null;            }            //开始预览            camera.startPreview();        }    };    //拍摄回调    private Camera.PictureCallback pictureCallback = new Camera.PictureCallback() {        @Override        public void onPictureTaken(byte[] data, Camera camera) {            // TODO Auto-generated method stub            //存储文件            new SavePictureTask().execute(data);            //回到预览设置            camera.startPreview();        }    };    //异步存储文件    class SavePictureTask extends AsyncTask<byte[], String, String>{        @Override        protected String doInBackground(byte[]... params) {            // TODO Auto-generated method stub            //手机不同，存储的文件路径可能也不同，可以按照自己的手机存储路径进行文件的存储。            File picture = new File("/storage/sdcard0/mhc.jpg");            try {                FileOutputStream filo = new FileOutputStream(picture.getPath());                //filo.write(params[0]);                filo.write(params[0]);                filo.close();            } catch (Exception e) {                // TODO: handle exception                e.printStackTrace();            }            CameraActivity01.this.finish();            return null;        }    }}

接着就是对文件的androidManifest.xml文件进行权限的设置：

 <uses-permission android:name="android.permission.CAMERA" />    <!--存储权限                    SD卡读写权限 -->    <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" />    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>    <!--Camera Feature 声明对camera feature的使用 -->    <uses-feature android:name="android.hardware.camera" />    <uses-feature        android:name="android.hardware.camera.autofocus"        android:required="false" />

这里有个从别人哪里下载下来的完整的拍照和摄影的demo,http://download.csdn.net/detail/duolezengjie/9310685