Question

尝试显示来自firebase的数据列表时，Android应用程序崩溃

public class exercisehowactivity extends Activity {

private DatabaseReference mDatabase;

private Button btnSearch;
private EditText actSearch;
private ListView lvexercise;
Exercise exercise;
String key;

private ArrayList<String> arrayList = new ArrayList <> ();
private ArrayAdapter<String> adapter;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate ( savedInstanceState );
    setContentView ( R.layout.activity_exerciseshow );

    mDatabase = FirebaseDatabase.getInstance ().getReference ().child("Exercise").child(key).child("name");

// DatabaseReference commandsRef = mDatabase.child（＆＃34; Exercise＆＃34;）;

    adapter = new ArrayAdapter <String> ( this, android.R.layout.simple_list_item_1, arrayList );

    btnSearch = (Button) findViewById ( R.id.btnSearch );
    actSearch = (EditText) findViewById ( R.id.actSearch );
    lvexercise = (ListView) findViewById ( R.id.lvexercise );

    mDatabase.addChildEventListener ( new ChildEventListener () {
        @Override
        public void onChildAdded(DataSnapshot dataSnapshot, String s) {

// Map map =（Map）dataSnapshot.getValue（）; // String string = dataSnapshot.getValue（String.class）;

            Exercise latest = dataSnapshot.getValue(Exercise.class);

            arrayList.add ( String.valueOf ( latest ) );

            adapter.notifyDataSetChanged ();
            lvexercise.setAdapter ( adapter );

        }

        @Override
        public void onChildChanged(DataSnapshot dataSnapshot, String s) {

        }

        @Override
        public void onChildRemoved(DataSnapshot dataSnapshot) {

        }

        @Override
        public void onChildMoved(DataSnapshot dataSnapshot, String s) {

        }

        @Override
        public void onCancelled(DatabaseError databaseError) {

        }
    } );
}

}

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Answer 1

您无需添加ChildEventListener。有一个firebase库可用于使用数据库中的数据填充listview。

这是链接，它还有一个指南。

https://github.com/firebase/FirebaseUI-Android/blob/master/database/README.md

android firebase列出来自节点的数据

1 个答案: