The program previously developed based on arcgis 10.1+vs2013 is now taken out to be modified, but the current version is arcgis10.7+vs2017/vs2019. After opening, no matter how to replace the reference version, an error is reported.
(For specific version correspondence, you can see this: ArcGIS Engine and Visual Studio version comparison table_What version of arcgis does vs2019 correspond to_QQ359677345's blog-CSDN blog )
Later, it was analyzed that the introduction error was caused by the incompatibility of three major versions: arcigs, vs, and program.net framework. It was found that the .net framework corresponding to arcgis 10.7 is already above 4.5. But the program is still 4.0. So I changed the running framework and it runs perfectly.
