最近做了一个搜索本地文件功能，搜索文件范围包括日志，apk，pdf，txt，jpg，zip，mp3，mp4等各种文件。使用了contentResolver访问本地文件数据，效果如下：

文件实体类FileBean：

data class FileBean(val fileName: String, val path: String)

文件搜索管理类SearchFileProvider：
查询的uri为MediaStore.Files.getContentUri("external")，查询条件为各位类型文件。

object SearchFileProvider {
    private const val MAX_FILE_COUNT = 30

    /**
     * 模糊查询本地文件
     */
    fun searchLocalFile(context: Context, key: String): ArrayList<FileBean> {
        var list = ArrayList<FileBean>()
        val volumeName = "external"
        val columns = arrayOf(MediaStore.Files.FileColumns.DATA)
        val selection = MediaStore.Files.FileColumns.DATA + " LIKE '%$key%.mp3' OR " +
                MediaStore.Files.FileColumns.DATA + " LIKE '%$key%.json' OR " +
                MediaStore.Files.FileColumns.DATA + " LIKE '%$key%.log' OR " +
                MediaStore.Files.FileColumns.DATA + " LIKE '%$key%.apk' OR " +
                MediaStore.Files.FileColumns.DATA + " LIKE '%$key%.mp4' OR " +
                MediaStore.Files.FileColumns.DATA + " LIKE '%$key%.pdf' OR " +
                MediaStore.Files.FileColumns.DATA + " LIKE '%$key%.txt' OR " +
                MediaStore.Files.FileColumns.DATA + " LIKE '%$key%.jpg' OR " +
                MediaStore.Files.FileColumns.DATA + " LIKE '%$key%.zip'"
        var cursor: Cursor? = null
        try {
            cursor = context.contentResolver.query(
                MediaStore.Files.getContentUri(volumeName),
                columns,
                selection,
                null,
                null
            )
            if (cursor != null) {
                while (cursor.moveToNext()) {
                    if (list.size < MAX_FILE_COUNT) {
                        val absolutePath = cursor.getString(0)
                        File(absolutePath).apply {
                            if (exists() && !TextUtils.isEmpty(name) && name.contains(".")) {
                                if (!TextUtils.isEmpty(name)) {
                                    var bean = FileBean(name, path)
                                    list.add(bean)
                                }
                            }
                        }
                    } else {
                        return list
                    }
                }
            }
        } catch (e: java.lang.Exception) {
            e.printStackTrace()
        } finally {
            try {
                if (cursor != null) {
                    cursor.close()
                    cursor = null
                }
            } catch (e: java.lang.Exception) {
            }
        }
        return list
    }
}

这里是列表adapter：

class FileAdapter(val context: Context): RecyclerView.Adapter<FileAdapter.FileViewHolder>() {
    private var datas = ArrayList<FileBean>()

    fun setDatas(datas: ArrayList<FileBean>) {
        this.datas = datas
        notifyDataSetChanged()
    }

    class FileViewHolder(itemView: View): RecyclerView.ViewHolder(itemView) {
        var ivIcon: ImageView?= null
        var tvName: TextView?= null

        init {
            ivIcon = itemView.findViewById(R.id.iv_icon)
            tvName = itemView.findViewById(R.id.tv_file_name)
        }
    }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): FileViewHolder {
        return FileViewHolder(LayoutInflater.from(context).inflate(R.layout.item_file, parent, false))
    }

    override fun onBindViewHolder(holder: FileViewHolder, position: Int) {
        holder.tvName?.text = datas[position].fileName
        setFileIcon(holder.ivIcon!!, datas[position].fileName)

        holder.itemView.setOnClickListener {

        }
    }

    override fun getItemCount(): Int {
        return datas.size
    }

    /**
     * 根据文件后缀类型设置对应类型图标
     */
    private fun setFileIcon(imageView: ImageView, fileName: String) {
        if (fileName.endsWith(".jpg") || fileName.endsWith(".mp4")) {
            imageView.background = context.resources.getDrawable(R.drawable.category_file_icon_pic_phone)
        } else {
            var drawableId = 0
            if (fileName.endsWith(".txt") || fileName.endsWith(".pdf")) {
                drawableId = R.drawable.category_file_icon_doc_phone
            } else if (fileName.endsWith(".zip")) {
                drawableId = R.drawable.category_file_icon_zip_phone
            } else if (fileName.endsWith(".mp3")) {
                drawableId = R.drawable.category_file_icon_music_phone
            } else if (fileName.endsWith(".apk")) {
                drawableId = R.drawable.category_file_icon_apk_phone
            } else {
                drawableId = R.drawable.ic_local_file
            }
            imageView.background = context.resources.getDrawable(drawableId)
        }
    }
}

然后，需要能够访问文件，别忘了加上6.0访问权限里的WRITE_EXTERNAL_STORAGE权限，获取本地文件访问的权限。并且注意，在targetsdk 29及以下，可以访问所有问题，高于29，则只能够访问到图片，视频，音乐这样的多媒体文件。