Android-ListActivity，添加页眉和页脚视图

Question

I'm using ListActivity, listview.

listView = getListView();

just working perfectly. I added footer view as

LayoutInflater inflater = getLayoutInflater();
listView.addFooterView( inflater.inflate( R.layout.footer, null ), null, false);

and everything was shiny but ugly, so i wanted to add this footer view (which contains only 1 edittext and only 1 button ) to header of listView as

LayoutInflater inflater = getLayoutInflater();
listView.addHeaderView( inflater.inflate( R.layout.footer, null ), null, false);

and suddenly everything goes wrong, and i get RuntimeException immediately.

Suspended(exception RuntimeException)
ActivityThread.performLaunchActivity(ActivityThread$ActivityRecord, Intent)
ActivityThread.handleLaunchActivity(ActivityThread$ActivityRecord, Intent)
ActivityThread.access$2200(ActivityThread, Activity$ActiviyRecord, Intent),
so on..

Why is it throws exception ? What is different between addFooterView and addHeaderView, and how can i add Header to ListActivity ?

UPDATE

So as you can read in comments, my logcat still doesn't work, but i just tried next at this moment:

} catch(Exception e){ 
  Writer result = new StringWriter(); 
  PrintWriter printWriter = new PrintWriter(result);
  e.printStackTrace(printWriter);
  String error = result.toString(); 
}

and afterward i put breakpoint, and i can read error in expressions section. it said :

java.lang.IllegalStateException: Cannot add header view to list -- setAdapter has already been called. 

it was instructive for all of us. After change sort of commands, it works perferctly.

Answer 1

As you log

java.lang.IllegalStateException: Cannot add header view to list -- setAdapter has already been called.

Listview's method addHeaderView or addFooterView must be called before setAdapter .

Answer 2

Create layout xml for header and footer

header_layout.xml

 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" >
    <TextView
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:gravity="center_horizontal"
    android:text="header"
    />
    </RelativeLayout>

footer_layout.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:gravity="center_horizontal"
android:text="footer"
/>
</RelativeLayout>

now in activity java file onCreate() method add

listView = (ListView) findViewById(R.id.listView1);
LayoutInflater inflater = getLayoutInflater();
    ViewGroup header = (ViewGroup) inflater.inflate(R.layout.header, listView,
            false);
    ViewGroup footer = (ViewGroup) inflater.inflate(R.layout.footer, listView,
            false);
    listView.addHeaderView(header, null, false);
    listView.addFooterView(footer, null, false);
    listView.setAdapter(adapter);

Answer 3

因此，如果要将标题视图添加到listView，则应在使用setListAdapter（）之前严格执行此操作，否则会导致IllegalStateException。