android - listview get item view by position

痞子三分冷 提交于 2019-11-26 00:33:11

问题


I have listview with custom adapter (base adapter). I want to get view from listview by position. I tried mListView.getChildAt(position) , but it is not working. How can i get item view by position?


回答1:


Use this :

public View getViewByPosition(int pos, ListView listView) {
    final int firstListItemPosition = listView.getFirstVisiblePosition();
    final int lastListItemPosition = firstListItemPosition + listView.getChildCount() - 1;

    if (pos < firstListItemPosition || pos > lastListItemPosition ) {
        return listView.getAdapter().getView(pos, null, listView);
    } else {
        final int childIndex = pos - firstListItemPosition;
        return listView.getChildAt(childIndex);
    }
}



回答2:


You can get only visible View from ListView because row views in ListView are reuseable. If you use mListView.getChildAt(0) you get first visible view. This view is associated with item from adapter at position mListView.getFirstVisiblePosition().




回答3:


Preferred way to change the appearance/whatever of row views once the ListView is drawn is to change something in the data ListView draws from (the array of objects that is passed into your Adapter) and make sure to account for that in your getView() function, then redraw the ListView by calling

notifyDataSetChanged();

EDIT: while there is a way to do this, if you need to do this chances are doing something wrong. While are few edge cases I can think about, generally using notifyDataSetChanged() and other built in mechanisms is a way to go.

EDIT 2: One of the common mistakes people make is trying to come up with their own way to respond to user clicking/selecting a row in the ListView, as in one of the comments to this post. There is an existing way to do this. Here's how:

mListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
    /* Parameters
    parent:     The AdapterView where the click happened.
    view:       The view within the AdapterView that was clicked (this will be a view provided by the adapter)
    position:   The position of the view in the adapter.
    id:         The row id of the item that was clicked. */
    @Override
    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
        //your code here
    }
});

ListView has a lot of build-in functionality and there is no need to reinvent the wheel for simpler cases. Since ListView extends AdapterView, you can set the same Listeners, such as OnItemClickListener as in the example above.




回答4:


workignHoursListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
    @Override
    public void onItemClick(AdapterView<?> parent,View view, int position, long id) {
        viewtype yourview=yourListViewId.getChildAt(position).findViewById(R.id.viewid);
    }
});



回答5:


Listview lv = (ListView) findViewById(R.id.previewlist);

    final BaseAdapter adapter = new PreviewAdapter(this, name, age);

    confirm.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub


            View view = null;

            String value;
            for (int i = 0; i < adapter.getCount(); i++) {

                view = adapter.getView(i, view, lv);

                Textview et = (TextView) view.findViewById(R.id.passfare);


                value=et.getText().toString();

                 Toast.makeText(getApplicationContext(), value,
                 Toast.LENGTH_SHORT).show();
            }



        }
    });


来源:https://stackoverflow.com/questions/24811536/android-listview-get-item-view-by-position

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