Should be combobox instead of combo. Also use .F. instead of !.T. for readability.

>hi,
>
>thank you,
>combo not work
>

>ThisForm.SetAll("visible", !.t., "combo")....not ok
>
>ThisForm.SetAll("visible", !.t., "textbox") ...ok
>ThisForm.SetAll("visible", !.t., "label")....ok
>ThisForm.SetAll("visible", !.t., "line").....ok
>

>>>ThisForm.SetAll("visible", !.t., "textbox" + "combo") OR
>>
>>This would set the visible for all "textboxcombo" controls in the container. Unless you've defined one, there is no such control
>>

>ThisForm.SetAll("visible", !.t., "textbox" AND "combo")
>>>

>>AND performs a logical (boolean) comparison. You are trying to perform a boolean operation on character arguements. This will result in a "Function arguement, type, or count is invalid" error.
>>
>>
>>
>>From VFP8 help (it might have changed in VFP9)
>>Container.SetAll(cProperty, Value [, cClass])
>>Use the SetAll method to set a property for all, or a certain class of, controls in a Container
>>
>>There is no option to have a list of controls.
>>

>>>ThisForm.SetAll("visible", !.t., "textbox" , "combo")

gives an error about the number of arguements
>>

>>>ThisForm.SetAll("visible", !.t., "textbox,combo")

does nothing since there is no "textboax,combo" control
>>>
>>
>>You can either have ALL controls made invisible
>>

>ThisForm.SetAll("visible", !.t.)

or use a separate line for each class of controls
>>

ThisForm.SetAll("visible", !.t., "textbox")
>>ThisForm.SetAll("visible", !.t., "combo")

>>
>>I would also recommend using .F. for false rather than !.T. I think it's easier to read and understand, but that's a personal preference unrelated to your real questions here