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

复制文件至Download目录中

复制代码

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
}

通过查询 DESCRIPTION字段判断文件是否存在

复制代码

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
 }