Question

dbRef.addValueEventListener(new ValueEventListener() {
        @Override
        public void onDataChange(final DataSnapshot dataSnapshot) {

            for (final DataSnapshot ds : dataSnapshot.getChildren()){
                arr.add(ds.child("name").getValue().toString()+"--"+ds.child("id").getValue().toString());
//ds.child("id").getValue().toString() this is how i get id from database
                lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
                    @Override
                    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                        Toast.makeText(getApplication(),"id :"+ds.getKey(),Toast.LENGTH_SHORT).show();
                    }
                });
            }
            lv.setAdapter(arrayAdapter);
        }
        @Override
        public void onCancelled(DatabaseError databaseError) {

        }
    });

这是我从Firebase获取数据并将其发布到列表视图中的方式。 onItemClick我想在toast中显示用户的id（来自数据库）。

Answer 1

尽量不要在Firebase方法中创建适配器的点击监听器。

lv.setAdapter(arrayAdapter);
lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
    @Override
    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
        String clicked = arrayAdapter.getItem(position).toString();
        Toast.makeText(MainActivity.this,
            "id :" + clicked,
            Toast.LENGTH_SHORT).show();
    }
});


dbRef.addValueEventListener(new ValueEventListener() {
    @Override
    public void onDataChange(final DataSnapshot dataSnapshot) {
        arrayAdapter.clear();
        for (DataSnapshot ds : dataSnapshot.getChildren()){
            arrayAdapter.add(ds.child("name").getValue().toString()+"--"+ds.child("id").getValue().toString());
        }
    }
    @Override
    public void onCancelled(DatabaseError databaseError) {

    }
});

我想在toast中显示用户的id（来自数据库）

然后你可以使用这样的东西

String clicked = arrayAdapter.getItem(position).toString();
String[] parts = clicked.split("--"); // This is because you added "--" on the other string. 
Toast.makeText(MainActivity.this,
    "id :" + parts[1],
    Toast.LENGTH_SHORT).show();

如果将firebase值映射到Java对象

，这会更简单一些

从Firebase检索数据并在listview中填充它们

1 个答案: