如何在Blackberry 10本机中获取ListView位置

Question

I am trying to load data from web-services into list-view and i am successfully able to load that particular data into my list-view.

But the problem i am facing is i am getting 10 data per page in list-view and when user scroll down it tries to load more data and when it loads more data into list-view, list-view start showing data from 1st data itself, instead of 1st data i want to show current data.

Ex. When user scrolls for more data that is page - 2 it will load another 10 data and now list-view contains 20 data, so currently user is at 10th position and loading more data so list-view should show from 11th data but instead of that it again start from 1st data itself, also when user loads 30 data then it should start showing data from 21 data but again it starting from 1st position.

So basically my question is how can i know the position of list-item and directly moves user to that particular position so directly user can see the current data.

The code i am trying is.

onScrollingChanged: {
              if (atEnd && scrolling == false
                   if (_app.powerDivert == 1) {
                          _app.powerDivert += 1;
                    }
                    if (connInfo.isConnected()) {
                              getPagewisePromotionList(_app.powerDivert);
                    }
                 }
             }

where powerDivert will increment the page-count and getPagewisePromotionList this is the function i am calling to add more data into the list-view.

i have also tried.

  onFirstVisibleItemChanged: {
            if (position < firstVisibleItem) {
             console.log("Scrolling Down")
             var size = _app.dataModel.size();
             var percent = firstVisibleItem / size * 100;
             console.log("Percent: " + percent);
                  if (percent > 60) {
                            if (_app.powerDivert == 1) {
                            _app.powerDivert += 1;
                           }
                           if (connInfo.isConnected()) {
                               console.log("inside percentage");
                               getPagewisePromotionList(_app.powerDivert);
                           }
                       }
                      } else if (position > firstVisibleItem) {
                       console.log("Scrolling Up");
                    }
                   position = parseInt(firstVisibleItem);
                }

and also with this code

onScrollingChanged: {
        if (ListItem.indexInSection + 5 == ListItem.indexPath) {
               if (_app.powerDivert == 1) {
                      _app.powerDivert += 1;
                }
               if (connInfo.isConnected()) {
                       getPagewisePromotionList(_app.powerDivert);
              }
         }
}

but it's giving me error like

Error: Accessing ListItem.indexInSection on a node that is not the root node in a list item visual. Try prefixing with the id of the item visual root node.
Error: Accessing ListItem.indexPath on a node that is not the root node in a list item visual. Try prefixing with the id of the item visual root node.

Please let me know if you need anything else.

Thank you in advance.

Answer 1

That Depends on you.How you are loading the data from services.If you are getting the data page wise then you can use this:

var indexPosition = (_app.powerDivert - 1) * 10;
lstPromotionListOnline.scrollToItem([ indexPosition ], ScrollAnimation.None);

Where powerdivert is your page_number and lstPromotionListOnline is your listview id

check this link for reference.