因为网站的验证码功能用到了System.Drawing.Common，需要在服务器中安装libgdiplus。
命令如下
yum install autoconf automake libtool
yum install freetype-devel fontconfig libXft-devel
yum install libjpeg-turbo-devel libpng-devel giflib-devel libtiff-devel libexif-devel
yum install glib2-devel cairo-devel
git clone https://github.com/mono/libgdiplus
cd libgdiplus
./autogen.sh
make
make install
cd /usr/lib64/
ln -s /usr/local/lib/libgdiplus.so gdiplus.dll
Git libgdiplus库时报错，提示“RPC failed; result=18, HTTP code = 200iB | 23.00 KiB/s”
原因：默认git库太小 不够用 需要重新配置
解决方法：
输入命令：
git config --global http.postBuffer 24288000
查看
git config --list
参考链接：
https://www.cnblogs.com/calvinK/p/8119112.html
https://blog.csdn.net/cooken/article/details/50903169
安装完之后 运行网站还是报错。
An unhandled exception has occurred while executing the request.
System.TypeInitializationException: The type initializer for 'System.DrawingCore.GDIPlus' threw an exception.
---> System.DllNotFoundException: Unable to load shared library 'gdiplus' or one of its dependencies. In order to help diagnose loading problems, consider setting the LD_DEBUG environment variable: libgdiplus: cannot open shared object file: No such file or directory
at System.DrawingCore.GDIPlus.GdiplusStartup(UInt64& token, GdiplusStartupInput& input, GdiplusStartupOutput& output)
at System.DrawingCore.GDIPlus..cctor()
--- End of inner exception stack trace ---
在另一篇文章上看到，
在centos上安装libgdiplus-devel；
命令如下：yum install libgdiplus-devel 安装完成后即可解决上面问题
运行后确实解决了，不知道是不是只要安装libgdiplus-devel就可以了，下次有机会再验证