CODEWITHSUNDEEP
androidandroid-layoutandroid-listviewandroid-asynctaskandroid-adapter
Renjith
Renjith

Reputation: 3617

Update the same listView on scroll

The purpose of the app is to fetch more data as the user scrolls down and updates existing ListView.

Code snippet handling user scroll is:

public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, 
                     int totalItemCount) {
    int totalVisible = firstVisibleItem + visibleItemCount;

     if (view.getAdapter() != null && 
        (totalVisible >= totalItemCount) && 
        totalItemCount != priorFirst && 
        visibleItemCount != totalItemCount) {
            Log.v("MyActivity", "onListEnd, extending list");
            priorFirst = totalItemCount;

            //params is array of values passed to business layer for data fetch
            String[] params = builder.toString().split("&");

            UIHandler uiHandler = new UIHandler(this, getParent());
            //start async task      
            EnquiriesRunner enquiriesRunner = new EnquiriesRunner(uiHandler);
            enquiriesRunner.execute(params);
    }

In the background, it invokes business layer.

protected ExceptionHandler<Object> doInBackground(String... params) {
    Object obj = enquiriesCaller.getEnquiries(params);
    return new ExceptionHandler<Object>(obj);
}

And pass the resulting data to UI handler which renders it to a listView using a custom adapter.

ListView enquiryView = (ListView) ((Activity) childContext).findViewById(R.id.enquiryListView);
CustomAdapter adapter = new CustomAdapter(childContext, msg.obj);
enquiryView.setAdapter(adapter);

msg.obj is the search result wrapped into an Object. This will be casted to required POJO reference in the adapter.

As you can see, each time listView is replaced with new set of data. Could anyone suggest a possible solution to update existing List?

Thanks in advance!

Upvotes: 0

Views: 4628

Answers (1)

Pankaj Singh
Pankaj Singh

Reputation: 2311

Try this link it will be useful for you.

http://benjii.me/2010/08/endless-scrolling-listview-in-android/

you can update ListView on Scrolling..

Upvotes: 1

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