Android Q Download文件存储

11 以上 存放 Download 目录中 只能通过uri 进行读取 且只能APP 安装后存放的文件 才有访问权限
APP 卸载之后 数据库中权限会被移除 无法再通过文件名称进行查询
这边通过比较描述字段进行判断是否下载过文件
11 以上APP进行卸载后在安装下载 会出现重复文件

不知是否还有其他解决方案

1. 将文件下载至缓存目录中

2. 复制文件至Download目录中

   fun copyFileToDownload(context:Context, oldPath:String, targetDirName:String) {
       if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
           copyFileToDownloadDir(context, oldPath, targetDirName)
       } else {
           var newPath = FileUtils.getExternalDownloadsPath() + File.separator +targetDirName + File.separator + File(oldPath).name
           var filePara = File(FileUtils.getExternalDownloadsPath() + File.separator + targetDirName)
           if (filePara.exists()) {
               filePara.mkdirs()
           }
           FileUtils.copyFile(oldPath, newPath)
       }
   }
   
    @RequiresApi(Build.VERSION_CODES.Q)
   fun copyFileToDownloadDir(context:Context, oldPath:String, targetDirName:String):Uri? {
       try {
           val oldFile = File(oldPath)
           //设置目标文件的信息
           val values = ContentValues()
           values.put(MediaStore.Images.Media.DESCRIPTION, oldFile.name)
           values.put(MediaStore.Files.FileColumns.DISPLAY_NAME, oldFile.name)
           values.put(MediaStore.Files.FileColumns.TITLE, oldFile.name)
           values.put(MediaStore.Files.FileColumns.MIME_TYPE, oldPath.getMimeType())
           val relativePath = Environment.DIRECTORY_DOWNLOADS + File.separator + targetDirName
           values.put(MediaStore.Images.Media.RELATIVE_PATH, relativePath)
           val downloadUri = MediaStore.Downloads.EXTERNAL_CONTENT_URI
           val resolver = context.contentResolver
           val insertUri = resolver.insert(downloadUri, values)
           if (insertUri != null) {
               val fos = resolver.openOutputStream(insertUri)
               if (fos != null) {
                   val fis = FileInputStream(oldFile)
                   fis.copyTo(fos)
                   fis.close()
                   fos.close()
                   return insertUri
               }
           }
       } catch (e:Exception) {
           e.printStackTrace()
       }
       return null
   }
   
   
   

3. 通过查询 DESCRIPTION字段判断文件是否存在

   fun findDownloadsFile(context:Context,targetDirName:String, description:String):ArrayList<Uri>? {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
            return findDownloadsUri4Description(context,targetDirName, description)
        } else {
            var newPath = FileUtils.getExternalDownloadsPath() + File.separator + targetDirName + File.separator + description
            var file = File(newPath)
            if (file.exists()) {
                var uri = FileUtils.getFile2Uri(file)
                var list = ArrayList<Uri>()
                uri?.let { list.add(it) }
                return list
            } else {
                return null

            }
        }
    }
        /**
     *  通过描述 字段 查询 下载目录中的文件
     * @param context Context
     * @param dirName String?  子目录
     * @param description String  描述字段
     * @return ArrayList<Uri>
     */
    @RequiresApi(Build.VERSION_CODES.Q)
    fun findDownloadsUri4Description(context:Context, dirName:String?, description:String):ArrayList<Uri> {
        val resultList = ArrayList<Uri>()
        try {
            val resolver = context.contentResolver
            val downloadUri = MediaStore.Downloads.EXTERNAL_CONTENT_URI
            var selection:String? = null

            var selectionArgs = mutableListOf<String>()
            if (dirName != null && dirName.isNotEmpty()) {
                selection = MediaStore.Files.FileColumns.BUCKET_DISPLAY_NAME + " = ? AND "
                selectionArgs.add(dirName)
            }
            selection = selection + MediaStore.Images.Media.DESCRIPTION + " = ? "
            selectionArgs.add(description)

            val resultCursor = resolver?.query(downloadUri, null, selection, selectionArgs.toTypedArray(), null)
            if (resultCursor != null) {
                val fileIdIndex = resultCursor.getColumnIndexOrThrow(MediaStore.Files.FileColumns._ID)
                while (resultCursor.moveToNext()) {
                    val fileId = resultCursor.getLong(fileIdIndex)
                    val pathUri = downloadUri.buildUpon().appendPath("$fileId").build()
                    resultList.add(pathUri)
                }
                resultCursor.close()
            }
        } catch (e:Exception) {
            e.printStackTrace()
        }
        return resultList
    }