Android-如何获取ListView项目在绝对位置？

Question

So ListView Adapter has the getView method and it's called everytime the display of the listview is changed... so the 0th element becomes the 1st element in the viewport. I think...

How do i basically access the 0TH element in the Listview? Not the 1st element in the viewport? First element in the entire ListView? I want tot access elements by an absolute index so it doesn't matter which one is visible, i want to access them based on their index in the ListView.

How do i do this?

Answer 1

You can't access any View in the ListView by index, because it's recycling them and essentially there are no views other than you see plus some cache.

And actually you shouldn't want to do this. If you want to manipulate with the ListView 's data, change the underlying collection via Adapter , so in overriden getView() of your adapter you can decide how to render the particular view (what background color to set in your case).

So you'll have something like this:

private class Item {
     Color getBgColor {...}
}

private class MyAdapter extends BaseAdapter { // or WhateverAdapter you have
    Item getItem(int id) {...}

    public View getView(int position, View convertView, ViewGroup parent) {
        ...
        convertView.setBackgroundColor(getItem(position).getBgColor());
        return convertView;
    }
}