如何从sd卡文件夹中读取文件名称

最新推荐文章于 2021-05-25 23:42:06 发布

翻译最新推荐文章于 2021-05-25 23:42:06 发布 · 1.1k 阅读

文章标签：

#android #read write

本文介绍了如何检查SD卡是否存在并可用，创建新文件夹，读取文件夹中文件名，以及通过文件过滤器筛选特定类型的文件。

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private boolean isExternalStoragePresent() {

        boolean mExternalStorageAvailable = false;
        boolean mExternalStorageWriteable = false;
        String state = Environment.getExternalStorageState();

        if (Environment.MEDIA_MOUNTED.equals(state)) {
            // We can read and write the media
            mExternalStorageAvailable = mExternalStorageWriteable = true;
        } else if (Environment.MEDIA_MOUNTED_READ_ONLY.equals(state)) {
            // We can only read the media
            mExternalStorageAvailable = true;
            mExternalStorageWriteable = false;
        } else {
            // Something else is wrong. It may be one of many other states, but
            // all we need
            // to know is we can neither read nor write
            mExternalStorageAvailable = mExternalStorageWriteable = false;
        }
        if (!((mExternalStorageAvailable) && (mExternalStorageWriteable))) {
            Toast.makeText(context, "SD card not present", Toast.LENGTH_LONG)
                    .show();

        }
        return (mExternalStorageAvailable) && (mExternalStorageWriteable);
    }

建立新文件夹

public static boolean createDirIfNotExists(String path) {
    boolean ret = true;

    File file = new File(Environment.getExternalStorageDirectory(), path);
    if (!file.exists()) {
        if (!file.mkdirs()) {
            Log.e("TravellerLog :: ", "Problem creating Image folder");
            ret = false;
        }
    }
    return ret;
}

读取文件夹中文件名字

File sdCardRoot = Environment.getExternalStorageDirectory();
File yourDir = new File(sdCardRoot, "yourpath");
for (File f : yourDir.listFiles()) {
    if (f.isFile())
        String name = f.getName();
        // make something with the name
}

使用filefitter

/**
 * Return list of files from path. <FileName, FilePath>
 *
 * @param path - The path to directory with images
 * @return Files name and path all files in a directory, that have ext = "jpeg", "jpg","png", "bmp", "gif"  
 */
private List<String> getListOfFiles(String path) {

    File files = new File(path);

    FileFilter filter = new FileFilter() {

        private final List<String> exts = Arrays.asList("jpeg", "jpg",
                "png", "bmp", "gif");

        @Override
        public boolean accept(File pathname) {
            String ext;
            String path = pathname.getPath();
            ext = path.substring(path.lastIndexOf(".") + 1);
            return exts.contains(ext);
        }
    };

    final File [] filesFound = files.listFiles(filter);
    List<String> list = new ArrayList<String>();
    if (filesFound != null && filesFound.length > 0) {
        for (File file : filesFound) {
           list.add(file.getName());
        }
    }

    return list;
}