如何在内部和外部存储中获得可用空间

Question

如何在内部和外部存储空间中获得可用空间？我正在开发一个下载ROM的应用程序，我必须检查是否有足够的可用空间来下载它。谁能帮我？提前谢谢！

Answer 1

根据user79758：

这是我正在使用的功能：

public static float megabytesAvailable(File f) {
    StatFs stat = new StatFs(f.getPath());
    long bytesAvailable = (long)stat.getBlockSize() * (long)stat.getAvailableBlocks();
    return bytesAvailable / (1024.f * 1024.f);
}

上述代码自2014年8月13日起引用了一些已弃用的功能。我在下面复制了更新版本：

public static float megabytesAvailable(File f) {
    StatFs stat = new StatFs(f.getPath());
    long bytesAvailable = (long)stat.getBlockSizeLong() * (long)stat.getAvailableBlocksLong();
    return bytesAvailable / (1024.f * 1024.f);
}

Answer 2

这是一种可以在android中检查内存状态的方法。我在我的申请中实施了。

public class AvailableSpaceHandler {

    //*********
    //Variables
    /**
     * Number of bytes in one KB = 2<sup>10</sup>
     */
    private final static long SIZE_KB = 1024L;

    /**
     * Number of bytes in one MB = 2<sup>20</sup>
     */
    private final static long SIZE_MB = SIZE_KB * SIZE_KB;

    /**
     * Number of bytes in one GB = 2<sup>30</sup>
     */
    private final static long SIZE_GB = SIZE_KB * SIZE_KB * SIZE_KB;

    //********
    // Methods

    /**
     * @return Number of bytes available on external storage
     */
    private static long getExternalAvailableSpaceInBytes(int newAndroidAPI) {
        long availableSpace = -1L;
        try {
            StatFs stat = new StatFs(Environment.getExternalStorageDirectory().getPath());
            if (newAndroidAPI >= Build.VERSION_CODES.KITKAT) {
                availableSpace = stat.getAvailableBlocksLong() * stat.getBlockSizeLong();
            } else {
                availableSpace = (long) stat.getAvailableBlocks() * (long) stat.getBlockSize();
            }
        } catch (Exception e) {
            e.printStackTrace();
        }

        return availableSpace;
    }


    /**
     * @return Number of kilo bytes available on external storage
     */
    public static long getExternalAvailableSpaceInKB(int newAndroidAPI) {
        return getExternalAvailableSpaceInBytes(newAndroidAPI) / SIZE_KB;
    }

    /**
     * @return Number of Mega bytes available on external storage
     */
    public static long getExternalAvailableSpaceInMB(int newAndroidAPI) {
        return getExternalAvailableSpaceInBytes(newAndroidAPI) / SIZE_MB;
    }

    /**
     * @return gega bytes of bytes available on external storage
     */
    public static long getExternalAvailableSpaceInGB(int newAndroidAPI) {
        return getExternalAvailableSpaceInBytes(newAndroidAPI) / SIZE_GB;
    }

    /**
     * @return Total number of available blocks on external storage
     */
    public static long getExternalStorageAvailableBlocks(int newAndroidAPI) {
        //newAndroidAPI to check API is < KITKAT
        long availableBlocks = -1L;
        try {
            StatFs stat = new StatFs(Environment.getExternalStorageDirectory().getPath());
            if (newAndroidAPI >= Build.VERSION_CODES.KITKAT) {
                availableBlocks = stat.getAvailableBlocksLong();
            } else {
                availableBlocks = stat.getAvailableBlocks();
            }
        } catch (Exception e) {
            e.printStackTrace();
        }

        return availableBlocks;
    }
}