MessageDecoder.MsgToString is missing several values defined in `WM_`

[hughbe]

Should be a 1-1 mapping.

[KlausLoeffelmann]

@hughbe: Can you provide more context for this issue?

[hughbe]

#2747 (comment)

Basically some values defined in the User32.WM enum are not handled in MessageDecoder. MsgToString

[Marmalade118]

Hi. I'd like to pick this one up if that's OK?

[RussKie]

Sure thing, thanks! Holler if you get stuck.

[Marmalade118]

Hi, I'm just after a bit of advice on how to proceed with something...

The first comment mentions that this should be a 1-2-1 mapping, but a number of the enum values in User32.WM have the same integer value when cast, causing problems with the case statement. How should these items be handled?

Thanks in advance.

[weltkante]

If these duplicates are in the control-specific range (1024 resp. 0x400 or above) they should not be translated to strings, unless the caller passes a parameter (e.g. an internal enum) which specifies for which control type they are.

(Even if you don't have duplicates, any message at WM_USER or above is control or application specific and doesn't have a fixed symbol or meaning. Messages in the application range must not be used by WinForms beacuse WinForms is a framework and not an application.)

If this is just for internal debugging and the control type is unknown a compromise would be to list all known meanings when translating to a string.

[elachlan]

@RussKie the existing code uses a switch case, should we just use a Dictionary instead? I remember reading a switch statement gets converted to a lookup anyway, so it might be easier to maintain in a dictionary?

Based on your previous comment in the PR, I imagine we just loop the User32.WM enum values and populate them into the dictionary using a prefix?