Question

I’m new to android programming and doing the first steps with Adapters (for a ListView).

Overriding the Adapter.getView I often see things like this:

public View getView(int position, View convertView, ViewGroup parent) {

    View itemView = null;

    if (convertView == null) {
        LayoutInflater inflater = (LayoutInflater) parent.getContext()
            .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        itemView = inflater.inflate(R.layout.table_row, null);
    } else {
        itemView = convertView;
    }

    // play with itemView

    return itemView;
}

My question is what speaks against this:

public View getView(int position, View convertView, ViewGroup parent) {

    View itemView = super(position, convertView, parent);

    // play with itemView

    return itemView;
}

This seems to work for me but I’m sure there’s a big point I’m missing 😀

Thanks for reading and sorry for my bad english …

Answer 1

You can use

View itemView = super(position, convertView, parent);

if only you are deriving from “ready to use” adapters (not BaseAdapter), like SimpleAdapter, or ArrayAdapter, as they already have their implementation for the getView().

Have a look at them: http://grepcode.com/file/repository.grepcode.com/java/ext/com.google.android/android/4.0.4_r2.1/android/widget/ArrayAdapter.java#361 for the ArrayAdapter, and
http://grepcode.com/file/repository.grepcode.com/java/ext/com.google.android/android/4.0.4_r2.1/android/widget/SimpleAdapter.java#113 for SimpleAdapter.

If you derive from BaseAdapter, you will have to manualy implement the whole method, as you’ve described in the first example, because it does not have it out of the box: http://grepcode.com/file/repository.grepcode.com/java/ext/com.google.android/android/4.0.4_r2.1/android/widget/BaseAdapter.java#BaseAdapter