我注意到文档中的这一段BackgroundTransferService ：
This property allows applications to request that background transfers proceed when only a cellular connection is available and when the device is on battery power. This is only a preference setting. It does not guarantee that transfers will take place under these conditions. The default value is None, which indicates that transfers should occur only when a Wi-Fi connection is available and when the device is connected to external power.
http://msdn.microsoft.com/en-us/library/windowsphone/develop/hh286419(v=vs.105).aspx
我不是以英语为母语的人，但这是否意味着 API 将掷骰子来选择上传是否有效，无论我选择什么首选项，传输可能会暂停或失败？
我想和你验证一下，乍一看，依赖随机性是没有意义的。