神经病啊，安装包不要面子哒！藏这么深
以前记得appleDeveloper上有Xcode各版本dmg下载地址，今天找了半天才找到，小样藏的够深的。
https://developer.apple.com/download/more/
记录一下藏在哪
1.https://developer.apple.com打开苹果开发网页。
2.点击Support
3.点击Development
4.点击Xcode
5.点击页面上蓝色的downloaded here
Downloading and Updating Xcode and SDKs
The current release of Xcode is available as a free download from the Mac App Store. The Mac App Store will notify you when an update is available or you can have macOS update automatically as it becomes available.
The latest beta versions of Xcode can be downloaded from the Downloads page. Previous versions of Xcode can also be downloaded here. To download beta or previous versions of Xcode, simply sign in with your Apple ID. Program membership is not required.
