Question

I stumbled about a strange problem with ListViews.

In the emulator the ListView shows no feedback, when an item is pressed for selection. I think I have seen that in the real thing, but I am not sure. I would expect that the list item gets selected (darker background) when it is pressed, so that the user can see, which item he pressed.

Do I have to code that?

RG

After seeing the comments, I tried the following:

I created a file res/color/backgroundstate.xml

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_selected="true"
          android:color="#888"/>
    <item android:state_pressed="true"
          android:color="#888"/>
    <item android:color="#eee"/>
</selector>

Then I use this in listitem.xml as a background color

<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:textColor="@color/helptextcolor"
    android:background="@color/backgroundstate"
    android:padding="10dp"
    android:textSize="16sp" >
</TextView>

When I display the ListView with

    ArrayAdapter adapter=new ArrayAdapter<String>(this,R.layout.listitem,names);
    LV.setAdapter(adapter);
    LV.invalidate();

the program crashes.

There are three exceptions connected with this. But the problem seems to be the last one XMLPullParserException:

<item> tag needs a drawable.

Now?

Answer 1

<item> indeed needs a drawable, not a color. You need a color drawable for that, like this:

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
  <solid android:color="#FFFF0000" />
</shape>

…and then put that into your item list.
Furthermore, this is a drawable and as such, it has to be in a /res/drawable-* directory, not in the /res/color/ directory.

To sum it up:

• (optional) put your colors in the /res/values/color.xml file with a name
• Create two shape drawables in xml, in the /res/drawable directory, one for the neutral color, one for the pressed color, in the fashion shown above
• Create a state list drawable like you did, but in the /res/drawable directory
• Use that as the background of your list item