这是有关表单协作的常见问题.最健壮的解决方案是在Form类中实现适当的接口，并传递接口引用而不是对Form的整个实例"的引用.请查看我过去的解决方案以获取更多详细信息:如何以两种形式在列表框之间复制所有项目 [ http://en.wikipedia.org/wiki/Accidental_complexity [ http://en.wikipedia.org/wiki/Loose_coupling [

This is the popular question about form collaboration. The most robust solution is implementation of an appropriate interface in form class and passing the interface reference instead of reference to a "whole instance" of a Form. Please see my past solution for more detail: How to copy all the items between listboxes in two forms[^].

Please also see other solutions in this discussion. If the application is simple enough, the solution could be as simple as declaring of some internal property in one form and passing a reference to the instance of one form to the instance of another form. For more complex projects, such violation of strictly encapsulated style and loose coupling could add up the the accidental complexity of the code and invite mistakes, so the well-encapsulated solution would be preferable.

Please see also:
http://en.wikipedia.org/wiki/Accidental_complexity[^],
http://en.wikipedia.org/wiki/Loose_coupling[^].

—SA