问题1: 直接从Apple官网下载下来的示例代码Command+R构建运行，XCode报错。错误信息为“Signing for “Scrumdinger” requires a development team. Select a development team in the Signing & Capabilities editor.”

解决:找到Targets->[Project Name]->Signing & Capabilities->Team选项，选择对应的开发者身份来签名；

问题2:When your XCode told you that it failed to prepare device for deployment.

解决:I will give you an advise：Restart your device.

问题2相关链接：failed to prepare device for deployment