嗨jammerDev，

Hi jammerDev,

您能告诉我们有关如何在测试过程中并排调试WebService的详细信息吗?它可以帮助我们尝试重现此问题并检查过程中发生了什么.

Could you tell us the detailed information about how do you debug the WebService side by side with the test process? It could help us try reproduce this issue on our side and check what happened in the process.

根据错误消息，出现此问题的原因是，当您尝试附加此过程时，测试过程正在调试中.因此，请确保测试过程不在调试中.

According to the error message, this issue occurs because the test process is debugging when you try attach this process. So please make sure the test process is not in debugging first.

并且由于您的Web服务托管在IIS上，请检查是否安装了Debug Diagnostics Tool v1.2.如果是，调试诊断服务将自动启动并附加到w3wp进程之一.请尝试关闭并禁用 这项服务.

And since your Web Service is hosted on IIS, please check whether you installed Debug Diagnostics Tool v1.2. If yes, the Debug Diagnostic Service will be started automatically and attached to one of w3wp processes. Please try turn off and disabling this service.

参考:

http://***.com/questions/24605673/visual-studio-2012-unable-attach-the-process-a-debugger-is-aready-attached

***的问候，
Weiwei

Best Regards,
Weiwei