>>>>>>>>I think there's a simple answer to this but I can't think of it or find it.
>>>>>>>>I want to set the character casing of all textboxes on a form to upper.
>>>>>>>>I get this far and can't access the charactercasing property of the control.
>>>>>>>>Any help appreciated.
>>>>>>>>
>>>>>>>>

>>>>>>>>      foreach (Control c in parentForm.Controls)
>>>>>>>>            {
>>>>>>>>                if (c is TextBox)
>>>>>>>>                {
>>>>>>>>
>>>>>>>>                }
>>>>>>>>            }
>>>>>>>>

>>>>>>>
>>>>>>>Did you try instead (not tested)
>>>>>>>

>>>>>>>var c as TextBox
>>>>>>>
>>>>>>>if (c!=null)
>>>>>>> {
>>>>>>>
>>>>>>>  }

>>>>>>>
>>>>>>>See
>>>>>>>
>>>>>>>https://msdn.microsoft.com/en-us/library/cscsdfbt.aspx?f=255&MSPPError=-2147217396
>>>>>>
>>>>>>
>>>>>>Thanks, Naomi
>>>>>>
>>>>>>I woke up from my trance and this did it
>>>>>>
>>>>>>

>>>>>>
>>>>>> foreach (Control c in parentForm.Controls)
>>>>>>            {
>>>>>>                if (c is TextBox)
>>>>>>                {
>>>>>>                    TextBox tb = c as TextBox;
>>>>>>                    tb.CharacterCasing = CharacterCasing.Upper;
>>>>>>                }
>>>>>>            }
>>>>>>

A Linq way:

foreach (Control c in parentForm.Controls.Where(x=>x is TextBox))
>>>>>            {
>>>>>                ((TextBox)c).CharacterCasing = CharacterCasing.Upper;
>>>>>            }

>>>>
>>>>Thank you, Viv.
>>>>I couldn't think of this syntax.
>>>>

>>>>((TextBox)c).CharacterCasing = CharacterCasing.Upper;
>>>>

>>>>The one I used worked but I prefer this one and I substituted it.
>>>
>>>A better LINQ way:
>>>

foreach (TextBox c in parentForm.Controls.OfType< TextBox>())
>>>            {
>>>                c.CharacterCasing = CharacterCasing.Upper;
>>>            }

>>Good. I'd forgotten about OfType(). Don't know if it's any faster because, internally, I think it does a 'is X' anyway ?
>
>Performance is probably similar, but it cleans up the code by getting rid of the lambda and cast.

I agree that the OfType() version looks cleaner but:
The runtime has to create the specialized type and the cast still has to be done. Source for OfType():

public static IEnumerable<TResult> OfType<TResult>(this IEnumerable source) {
            if (source == null) throw Error.ArgumentNull("source");
            return OfTypeIterator<TResult>(source);
        }
 
        static IEnumerable<TResult> OfTypeIterator<TResult>(IEnumerable source) {
            foreach (object obj in source) {
                if (obj is TResult) yield return (TResult)obj;
            }
        }

Just nit-picking... :-}