I have tried many pits on the Internet, but the
first pit: 
the second pit:
The third pit:
… … … … …
Solution:
Later, I saw that my C++ plug-in has been updating accessories, but it can't be completed, and then I directly searched for an article
based on this problem. The main problem is the C++ plug-in configuration problem:
It may be the C/C++ that you have transferred by yourself, but you can't download the accessories all the time, although the C/C++ plug-in has been installed, the
error is as follows
vscode Downloading package ‘C/C++ language components (Windows)‘ Failed.问题解决
First download the offline installation package on the official website: https://github.com/Microsoft/vscode-cpptools/releases
windows64-bit system, the download content is cpptools-win32.vsix
Then open vscode, open the extension, click the three dots in the upper right corner, select Install form VSIX. Then select the downloaded file. After the installation is complete, restart it.
Reboot and you're done!