啟動照相機
Intent it = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
//假設你要將相片存在 /sdcard/xxx.jpg 中
File f = new File(Environment.getExternalStorageDirectory().getAbsolutePath() + "/xxx.jpg");
it.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(f));
startActivity(it, 0);