这听起来很傻.该表单显然是正在进行的工作的副本，并且构建操作设置为无.将其设置为 Compile 会使设计器正常运行.

This will sound silly. The form is apparently a duplicate for a work in progress and the build action was set to None. Setting it to Compile caused the designer to act as normal.

如果设计师至少能指出您正确的方向就好了.问题解决了.

It would be nice if the designer would at least point you in the right direction. Problem solved.