郁闷的错--未判断磁盘剩余空间

public static boolean canSaveTheFileSize(int wantSaveFileSize) {
??? ??? boolean flag = false;
??? ??? String storageDirectory = Environment.getExternalStorageDirectory()
??? ??? ??? ??? .toString();
??? ??? StatFs stat = new StatFs(storageDirectory);
??? ??? int availableSize = stat.getAvailableBlocks()*stat.getBlockSize();
??? ??? if(availableSize > wantSaveFileSize)flag = true;
??? ??? else flag = false;
??? ??? return flag;
??? }