Set a background color to a selected ListView Item in android

Question

I have a listview which displays several items. Now I want to scroll to some specific item (e.g. the 33th item). I know that this can be done via

myList.setSelection(32);

But on the UI the item doesn't receive any highlighting (because it is in touch mode?!). How can I apply a specific background color for this item? I tried

myList.getSelection().getSelectedView().setBackgroundColor(Color.Red);

but i get a NullPointerException because getSelectedView() returns null. Is there a way to achieve this highlighting? I have to notify the user somehow about which item is the "active" one...

Solution 1

Try this, it will work-

myList.getChildAt(myList.getSelectedItemPosition()).setBackgroundColor(Color.RED);

Solution 2

1. To highlight the selected item, you should request focus for the listView and run setSelection() in the UI thread. This worked for me:

runOnUiThread(new Runnable() {
    public void run() {
        myList.requestFocus();
        myList.setSelection(position);
    }
});

2.To apply a specific color to an item. You can use customized listItem.

a. Set customized lisItem for your listView:

ArrayAdapter<String> listAdapter = new ArrayAdapter<String>(this, R.layout.customizedlistitem,arrListView);
myList.setAdapter(listAdapter);

b. In your layout folder, create customizedlistitem.xml

<TextView xmlns:android="http://schemas.android.com/apk/res/android"  
    android:id="@+id/customizedlistitem"   
    android:layout_width="match_parent"   
    android:layout_height="wrap_content"
    android:background="@drawable/customizedbackground"/>   

c. In your drawable folder, create customizedbackground.xml like this:

<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_selected="true" android:state_pressed="false" android:drawable="@color/RED"></item>
    <item android:state_pressed="true" android:drawable="@color/GREEN"></item>      
    <item android:drawable="@color/BLACK"></item>   <!-- for other state -->        
</selector>

d. Make sure color RED, GREEN and BLACK was defined in your project (you can define it in color.xml under values folder):

<?xml version="1.0" encoding="utf-8"?>

<resources>  
     <color name="RED">#FF0000</color>
     <color name="GREEN">#008000</color>
     <color name="BLACK">#000000</color>
</resources>

Solution 3

ListView in xml file:

<ListView android:id="@+id/android:list" android:layout_width="fill_parent"
        android:layout_height="wrap_content" 
        android:layout_below="@+id/Tablayoutdesign"
        android:cacheColorHint="#000000"
        android:dividerHeight="1dip"
        android:layout_marginTop="63dip"
        android:layout_marginBottom="40dip"

        />

Create new xml with listselector name like:

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android"> 

  <!-- Selected --> 
  <item 
    android:state_focused="true" 
    android:state_selected="false" 
    android:drawable="@drawable/focused"/> 

  <!-- Pressed -->
  <item 
    android:state_selected="true" 
    android:state_focused="false"
    android:drawable="@drawable/selected" /> 

</selector>

Create colors.xml file like:

<resources>
    <drawable name="focused">#ff5500</drawable>
    <drawable name="selected">#FF00FF</drawable>
</resources>

In your java code:

ListView lv= (ListView) findViewById(R.id.list);
lv.setSelector( R.drawable.listselector);