如何从Firebase取消下载任务？每当我点击ProgressDialog的某处时，我想取消下载。这是我的下载ActivityExamesActivity.java所在的部分。看起来像://DownloadtheFileonButton(Download)click:bDownload.setOnClickListener(newView.OnClickListener(){@OverridepublicvoidonClick(Viewv){//InitalizingtehSpinner-to-Stringfunctions:Grade=spClasse.getSelectedItem