class surface extends SurfaceView implements SurfaceHolder.Callback {

         SurfaceHolder sfholder;

         Camera camera;

         Bitmap bitmap;

         public surface(Context context) {
             super(context);
             // TODO Auto-generated constructor stub

             sfholder = getHolder();
             sfholder.addCallback(this);
             sfholder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
         }

         public void surfaceChanged(SurfaceHolder holder, int format, int width,
                 int height) {
             // TODO Auto-generated method stub
              Camera.Parameters parameters = camera.getParameters();
             parameters.setPictureFormat(PixelFormat.JPEG);
             parameters.setPreviewSize(320, 480);
             parameters.setPictureSize(320, 480);
             camera.setParameters(parameters);
              camera.startPreview();
         }

         public void surfaceCreated(SurfaceHolder holder) {
             // TODO Auto-generated method stub

             try {
                 camera = Camera.open();
                 camera.setPreviewDisplay(sfholder);
             } catch (Exception e) {
                 camera.release();
                 camera = null;
             }
         }

         public void surfaceDestroyed(SurfaceHolder holder) {
             // TODO Auto-generated method stub
              camera.stopPreview();
             camera = null;

         }
         //拍照
         public void takePicture()
         {
             if (camera != null)
             {
                 camera.takePicture(null, null, jpegCallback);
             }
         }

         //拍照并且保存的回調函數

         private PictureCallback jpegCallback = new PictureCallback() {

             public void onPictureTaken(byte[] data, Camera camera) {
                 // TODO Auto-generated method stub
                 try
                 {
                 bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);
                 File file = new File("/sdcard/camera1.jpg");
                 BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(file));
                 bitmap.compress(Bitmap.CompressFormat.JPEG, 80, bos);
                 bos.flush();
                 bos.close();
                 Canvas  canvas= sfholder.lockCanvas();
                 canvas.drawBitmap(bitmap, 0,0, null);
                 sfholder.unlockCanvasAndPost(canvas);
                 }
                 catch(Exception e)
                 {
                     e.printStackTrace();
                 }
             }
         }
     }

@Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        // TODO Auto-generated method stub
        if (keyCode == KeyEvent.KEYCODE_DPAD_CENTER)
            sf.takePicture();
        return super.onKeyDown(keyCode, event);
    }

android:name="Android.permission.WRITE_EXTERNAL_STORAGE">

if (Environment.getExternalStorageState().equals(android.os.Environment.MEDIA_MOUNTED)) {
         File    sdcardPath = Environment.getExternalStorageDirectory();
            setTitle(sdcardPath.getName()); //將SD卡路徑名字設置為標題，只是為了讓大家看的更明白些
        } else {
            Toast.makeText(RecordTest.this, "沒有SD卡", 1000).show();
        }