Problem with choice-box: "Invalid number of items: .."

I have Problem by initializing a choice box:

Skip sl_exportviews = GetViewsOfModule(m)

put(sl_exportviews, USE_CURRENT_VIEW_CONFIG, "")

string s_exportviews[]

s_exportviews = ConvertSkipListKeysToStringArray(sl_exportviews)

delete sl_exportviews

int i_no_of_views = sizeof(s_exportviews)

Line xx:  viewChoiceDBE = choice(exportBox_, LabelExportView, s_exportviews, i_no_of_views, 0, 40, false) //drop down selector

viewChoiceDBE->"left"->"inside"->tabStrip;.

At line 11 I get following error:

-R-E- DXL: <

Line xx:Invalid number of items: 11, maximum is 0

-I- DXL: execution halted.

Does anybody know why this happens?

The passed string-array s_exportviews has valid elements (tested and verified).

Re: Problem with choice-box: "Invalid number of items: .."
thsturm - Wed Jul 26 03:20:58 EDT 2017

- where is the string array defined?

- where are the strings (I asume the name of the view) stored?

- what does 'ConvertSkipListKeysToStringArray()' realy return? An string array, a pointer to a string array?

My assumption is: the string array lives on the call-stack. 'sizeof()'' gives you the size of the array on the stack.

Calling 'choice' overwrites the string array on the stack and therefore the call crashes.

Re: Problem with choice-box: "Invalid number of items: .."
MarcoLuk - Wed Jul 26 04:57:41 EDT 2017

Hello thsturm,

thank you very much for your helpful answer!

Indeed the function "ConvertSkipListKeysToStringArray()" is implemented like follows:

//Converts skiplist to string array.

//Note: Key-Elements of skiplist must be of type string.

string ConvertSkipListKeysToStringArray(Skip sl)[]

{

int i_size = GetSkipListSize(sl)

int i_idx = 0

string s_elements[i_size]

for none in sl do{

string s_key = (string key sl)

s_elements[i_idx] = s_key

i_idx++

}

return s_elements

}

Obviously the variable "s_elements" is being handled on the stack.

I solved the problem by using the type Array instead of string[].