1.手机连接上打印机的wifi后
public void print(final IWebview iWebview, JSONArray array) {
this.mIWebview = iWebview;
this.activity = iWebview.getActivity();
this.mContext = iWebview.getContext();
this.mCallBackID = array.optString(0);
path = array.optString(1);
//申请sd卡权限
ActivityCompat.requestPermissions(activity, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE,
Manifest.permission.READ_EXTERNAL_STORAGE, Manifest.permission.MOUNT_UNMOUNT_FILESYSTEMS},4);
PrintHelper photoPrinter = new PrintHelper(activity