非静态字段需要对象引用

Question

What am I doing wrong here?

return listBoxKeywords.Items[rnd.Next(0, listBoxKeywords.Items.Count)].ToString();

I get the following error:

Error 1 An object reference is required for the non-static field, method, or property

Answer 1

This error means that the function returning the random item is static.

Either remove the static keyword from the method declaration (and thus make it part of the existing instance), or pass the list box as parameter to the function when calling it.