What is the purpose of `convertView` in ListView adapter?
android, java
Solution
From the documentation,
convertView - The old view to reuse, if possible. Note: You should check that this view is non-null and of an appropriate type before using. If it is not possible to convert this view to display the correct data, this method can create a new view.
In other words, this parameter is used strictly to increase the performance of your `Adapter`. When a `ListView` uses an `Adapter` to fill its rows with `View`s, the adapter populates each list item with a `View` object by calling `getView()` on each row. The Adapter uses the `convertView` as a way of recycling old `View` objects that are no longer being used. In this way, the `ListView` can send the Adapter old, "recycled" view objects that are no longer being displayed instead of instantiating an entirely new object each time the Adapter wants to display a new list item. This is the purpose of the `convertView` parameter.
Problem
In android, I usually use `MyAdapter extends ArrayAdapter` to create view for the `ListView`, and as a result, I have to override the function ``` public View getView(int position, View convertView, ViewGroup parent) { // somecode here } ``` However, i don't know exactly what `convertView` and `parent` do! Does anyone have a suggestion? More detail, more help! Thanks!