判断SD卡的剩余容量

   /**
     * 判断SD卡的剩余容量
     * 
     */
    public long isAvaiableSpace(int sizeMb) {
        long availableSpare = 0;
        if (android.os.Environment.getExternalStorageState().equals(android.os.Environment.MEDIA_MOUNTED)) {
            String sdcard = Environment.getExternalStorageDirectory().getPath();
            StatFs statFs = new StatFs(sdcard);
            long blockSize = statFs.getBlockSize();
            long blocks = statFs.getAvailableBlocks();
            availableSpare = (blocks * blockSize) / (1024 * 1024);
            Log.d("剩余空间", "availableSpare = " + availableSpare);
        }
        return availableSpare;
    }