how to auto select the first index in a sparks List control in flex4

Question

hi

i have a spark List control. it has a dataProvider that shows reply from twitter search.

i have created a function for change handler like this:

protected function list_changeHandler(event:IndexChangeEvent):void { ta.text = coverflow.selectedItem.title; }

so, whenever i select each of the items in the List i will see the message(ta.text) but now, instead of me manually clicking the first time, i want it to automatically click/select the first item and see the first message(ta.text)

how do i do it? ...

newbie to flex ... :p

Answer 1

Actually, in thinking about this, you probably need to subclass the list and override the dataProvider setter.

override public function set dataProvider(data:*) : void {
  super._dataProvider = data;
  // This will be an ArrayCollection or XMLListCollection, so will have a length
  if (data && data.length > 0) {
    this.selectedIndex = 0;
    invalidateDisplayList();
  }
}

Answer 2

Hi, james

How about to try this solution? :)

Your list control also has event name creationComplete (similar to change event). Try to select your first item with this:

protected function list1_creationCompleteHandler(event:FlexEvent):void
{
    if(event.target.dataProvider != null )
    {
        (event.target as List).selectedIndex = 0;
    }
}

You may not need to convert event.target to List. but it may help you access code completion while you are coding.

Answer 3

Set the dataProvider of the list, set the selected item, and then either call your handler function directly with a null parameter, or make the list dispatch an indexChanged event so that your handler function gets executed.