Check if GUICTRL exists.

[MrBeatnik]

Hi folks.

I create some controls on a form dynamically, depending on what is returned from a sepcific function.

I want to delete all existing controls first, and then recreate (there could be different number of controls each time).

This is generally fine - a For...Next loop can loop through the control array and do a GUICTRLDelete.

However, there is no control created until the data is passed for the first time.

This means that the GUICTRLDelete errors out and kills the program.

Is there a way to check if a GUIcontrol exists?

An example code may help demonstrate what I am trying to achieve:

Dim $controlArray[1]

Func _displayData($myData)
    
    ;First clean out data
    For $myCount = 0 to UBound($controlArray)-1 Step +1
        GUICtrlDelete ( $controlArray[$myCount] )   ;FAILS HERE THE FIRST TIME AS CONTROL HAS NOT BEEN CREATED YET
    Next

    ;Now set data
    ReDim $controlArray[UBound($myData)]
    $topInc = 0
    For $myCount = 0 to UBound($myData)-1 Step +1
        $controlArray[$myCount] = GUICtrlCreateLabel($myData[$myCount], 56, 136 + $topInc, 81, 22, -1, 0)
        $topInc += 31
    Next
EndFunc

Note this example code of course doesn't work on its own.

It requires the GUI to be created etc, and the function to be called with data passed.

Thanks!

[wakillon]

Try a GUICtrlGetState before delete ctrl ...

[KaFu]

The code shouldn't fail because of GUICtrlDelete(), as it returns 0 if the function fails and does not crash. Maybe they arrays do not exist?

Global $controlArray

Func _displayData($myData)

    ;First clean out data
    If IsArray($controlArray) Then
        For $myCount = 0 To UBound($controlArray) - 1
            GUICtrlDelete($controlArray[$myCount]) ;FAILS HERE THE FIRST TIME AS CONTROL HAS NOT BEEN CREATED YET
        Next
    EndIf

    ;Now set data
    If IsArray($myData) Then
        Dim $controlArray[UBound($myData)]
        $topInc = 0
        For $myCount = 0 To UBound($myData) - 1
            $controlArray[$myCount] = GUICtrlCreateLabel($myData[$myCount], 56, 136 + $topInc, 81, 22, -1, 0)
            $topInc += 31
        Next
    EndIf
EndFunc   ;==>_displayData

Edited November 18, 2010 by KaFu

[MrBeatnik]

The code shouldn't fail because of GUICtrlDelete(), as it returns 0 if the function fails and does not crash. Maybe they arrays do not exist?

Have it sorted, although slightly strange behaviour I think.

The array does exist, but I actually have a 2d array.

I should have mentioned this the first time.

Although I expected GUICtrlDelete() to return 0 (as per the help), it was actually crashing because, when trying to check the control, it found an array.

Doesn't work:

GUICtrlDelete($controlArray[$myCount])

Does work:

GUICtrlDelete($controlArray[$myCount])[0]

So GUICtrlDelete() fails and crashes if the object is an array.

I feel that GUICtrlDelete() should have error control to return -1 or something if an expect object wasn't found, rather than crashing out.

Of course, had this not have crashed out, the control would not have been deleted if it did exist as I wasn't referencing the control directly, but the first array in which the second array of controls is held. It was invalid code.

Thanks for the pointer KaFu!

[BrewManNH]

What EXACTLY is the error message you receive when it fails? Also, please post an example script that actually "works" to demonstrate the error so that we can see what is happening and where. Trying to trouble shoot this problem with a small snippet of code isn't going to help much and not knowing what error message you receive makes any attempts at helping a guess and nothing more.

[MrBeatnik]

What EXACTLY is the error message you receive when it fails? Also, please post an example script that actually "works" to demonstrate the error so that we can see what is happening and where. Trying to trouble shoot this problem with a small snippet of code isn't going to help much and not knowing what error message you receive makes any attempts at helping a guess and nothing more.

As per my last post, it is fixed.