在 .designer.cs 中控制创建

Question

I have some user controls in our app that refer back to the form they're sitting on to get some initialisation values. Depending on the form they're on different behaviours are needed.

So the user controls catch OnLoad and ParentChanged events, and you FindForm to gain access to the form they're sat on... and all has been good for a couple of years.

However, last week we started to have problems with some controls not initialising properly, and after much searching I can see that what's happening is that if the controls are sat on a container rather than directly on the form, then when the ParentChanged event of the control fires, it could be that the container is not yet added to the form and so FindForm does not work.

The odd thing is that this has only just started happening, and it seems that since we upgraded to the latest VS, when a form is saved after editing, the designer is massively changing the order in which controls are created and sometimes this causes a fail.

Does anyone know if/why the VS designer behaviour has changed? And also, if there is anyway to control the create order of form controls in the designer file?

I can manually edit the designer file to fix, but on a resave, VS puts it back the way it wants again.

Answer 1

So while this might have worked for you for some time, the core problem lies in the handy message included in every Designer.cs file.

  /// <summary>
  /// Required method for Designer support - do not modify
  /// the contents of this method with the code editor.
  /// </summary>

In reality this message should really apply to anything in the Designer.cs file. I would gently suggest that you should take a hard look at your code and why you're doing what you're doing, and change it as soon as possible to not rely on Designer.cs file modifications.