I am trying to load a form class from a program running as a tray icon that originally used
FileList frmFileList = new FileList();
Now instead of a filelist I want to use a custom form but I get the error:
Error 1 'System.Windows.Forms.Control.ControlCollection' does not contain a definition for 'Cast' and no extension method 'Cast' accepting a first argument of type 'System.Windows.Forms.Control.ControlCollection' could be found (are you missing a using directive or an assembly reference?)
Any ideas?
It sounds like you forgot using System.Linq;
at the top of your source file. But since you didn't post the sources, I can't say for sure. Posting the line of code that causes the error message, and the using
directives that are in that same file would help.
Are you sure you are not trying something like this?
FileList frmFileList = new SomethingDifferent();
If so, change the FileList on the left side to SomethingDifferent.
来源:https://stackoverflow.com/questions/4568815/c-how-to-call-a-form-object-from-a-tray-based-application