如何获得Android SD卡上的可用空间?

你必须使用 StatFs 班级。下面是一个如何使用它的例子,从源代码到手机上的设置应用程序。

        if (status.equals(Environment.MEDIA_MOUNTED)) {
        try {
            File path = Environment.getExternalStorageDirectory();
            StatFs stat = new StatFs(path.getPath());
            long blockSize = stat.getBlockSize();
            long totalBlocks = stat.getBlockCount();
            long availableBlocks = stat.getAvailableBlocks();

            mSdSize.setSummary(formatSize(totalBlocks * blockSize));
            mSdAvail.setSummary(formatSize(availableBlocks * blockSize) + readOnly);

            mSdMountToggle.setEnabled(true);
            mSdMountToggle.setTitle(mRes.getString(R.string.sd_eject));
            mSdMountToggle.setSummary(mRes.getString(R.string.sd_eject_summary));

        } catch (IllegalArgumentException e) {
            // this can occur if the SD card is removed, but we haven't received the 
            // ACTION_MEDIA_REMOVED Intent yet.
            status = Environment.MEDIA_REMOVED;
        }

StatFS . 如果您传入 Environment.getExternalStorageDirectory() 到构造函数(转换为 String

您可能需要重新启动才能获得准确的结果:

StatFs stat = new StatFs(Environment.getExternalStorageDirectory().getAbsolutePath());
stat.restat(Environment.getExternalStorageDirectory().getAbsolutePath());
long available = ((long) stat.getAvailableBlocks() * (long) stat.getBlockSize());

自API级别9起可用:

Environment.getExternalStorageDirectory().getUsableSpace();

http://developer.android.com/reference/java/io/File.html#getUsableSpace()