通过WiFi连接手机和车机，在车机APP测试上一曲按钮

[lpz191]

Bug Report

通过WiFi连接手机和车机，在车机APP测试上一曲按钮

Reproduction Steps

1 | 正常启动QTHMI程序，并点击Application 2 | 在手机上启动SDL Example APP，输入SDL的IP地址，并点击Connect 3 | 在车机端启动APP 4 | 点击上一曲按钮

Expected Behavior

车机正常启动并显示Application界面：YES 车机显示SDL Example应用: YES 车机端进入SDL Example界面: YES 手机端进入锁屏界面: YES 车机端播放上一曲：YES

Observed Behavior

车机端没有音频播出，也无法切换至上一曲

OS & Version Information

• OS/Version: iOS 11.4
• SDL Core Version: [The version of SDL Core you were using when the bug occurred]
• SDL Proxy Version：[The version of SDL Android/ SDL iOS you were using when the bug occurred]
• Testing Against: [What you tested with to observe this behavior. Proxy, App, HMI etc.]

Test Case, Sample Code, and / or Example App

[Paste a link to a PR, gist, or other code that exemplifies this behavior]

[zenghuan1]

测试app无音乐可切换,点击上一曲之后,log中有上发切换上一曲的消息,但是无切换到上一曲的消息发送回来. 目前分析为测试app无消息返回的问题.