BeaconNetwork.downloadDFU(parameter).apply {
    if (Utils.isExternalStorageLegacy()) {
        // 分区存储
        val contentUri = MediaStore.Downloads.getContentUri("external")

        val contentValues = ContentValues()
        contentValues.put(
            MediaStore.Downloads.RELATIVE_PATH,
            Environment.DIRECTORY_DOWNLOADS
        )
        contentValues.put(
            MediaStore.Downloads.DISPLAY_NAME,
            "${fileName}.dfu"
        )
        contentResolver.insert(contentUri, contentValues)?.let {
            launch(Dispatchers.IO){
                val readBytes = byteStream().readBytes()
                contentResolver.openOutputStream(it)?.use {out ->
                    out.write(readBytes)
                }
                fileNameLiveData.postValue("${fileName}")
                fileByteLiveData.postValue(readBytes)
                fileSizeLiveData.postValue(readBytes.size)

                handler.sendEmptyMessage(0x0002)
            }
        }?: let {
            Log.e(TAG, "downloadDfu: null" )

            handler.sendEmptyMessage(0x0002)
        }

        return@coroutineScope
  }
}

同一份代码，有些文件无法保存。控制台打印 

E/SQLiteDatabase: Error inserting UNIQUE constraint failed: files._data (Sqlite code 2067 SQLITE_CONSTRAINT_UNIQUE), (OS error - 2:No such file or directory)   

downloadDfu: null

但是是修改文件名之后就能正常保存。不知道是什么原因，有大神知道吗