判斷設備是否具備攝像頭

 private boolean hasCamera(){
  PackageManager pm = this.getPackageManager();
  return pm.hasSystemFeature(PackageManager.FEATURE_CAMERA)//是否有後置相機
    || pm.hasSystemFeature(PackageManager.FEATURE_CAMERA_FRONT)//是否有前置相機
    || Build.VERSION.SDK_INT < Build.VERSION_CODES.GINGERBREAD
    || Camera.getNumberOfCameras() > 0;
 }