【问题标题】:How to retrieve the data from firebase into a ListView?如何将数据从 firebase 检索到 ListView?
【发布时间】:2016-12-18 01:19:36
【问题描述】:

我看到了这段代码,但它在 TextView 中检索数据,但我希望将其设置在 ListView 中。
我该怎么做?
这是我试过的代码:

ref.addValueEventListener(new ValueEventListener() {

    @Override
    public void onDataChange(DataSnapshot snapshot) {
        for (DataSnapshot postSnapshot : snapshot.getChildren()) {
            //Getting the data from snapshot 
            Person person = postSnapshot.getValue(Person.class);

            //Adding it to a string 
            String string = "Name: "+person.getName()+"\nAddress: "+person.getAddress()+"\n\n";

            //Displaying it on textview
            textViewPersons.setText(string);
        }
    }

    @Override
    public void onCancelled(FirebaseError firebaseError) {
        System.out.println("The read failed: " + firebaseError.getMessage());
    }

这是我的 ListView 代码:

messageList = (ListView) findViewById(R.id.messageList);
messages = new ArrayList<Message>();
mAdapter = new MyArrayAdapter(this, messages);
messageList.setAdapter((ListAdapter) mAdapter);

【问题讨论】:

标签: android listview firebase firebase-realtime-database


【解决方案1】:

您可以使用FirebaseUI for Android 库。

只需添加依赖项(0.4.4 适用于 firebase 9.4.0 库):

dependencies {
    // Single target that includes all FirebaseUI libraries
    compile 'com.firebaseui:firebase-ui:0.4.4'
}

然后将 ListView 与 Adapter 连接(在本例中为人员列表):

ListView personsView = (ListView) findViewById(R.id.mylist);
DatabaseReference ref = FirebaseDatabase.getInstance().getReference();
mAdapter = new FirebaseListAdapter<Person>(this, Person.class, R.layout.myItemLayout, ref) {
        @Override
        protected void populateView(View view, Person person, int position) {
             //Populate the item           
         }
    };
personsView.setAdapter(mAdapter);

【讨论】:

    【解决方案2】:

    首先,您需要修复对象类型。您的适配器(和支持 ArrayList)具有 Message 对象,但 Firebase 为您提供 Person 对象。

    假设你让 Adapter 接受 Person 对象,只需添加到 Adapter

    ref.addValueEventListener(new ValueEventListener() {
    
         @Override
        public void onDataChange(DataSnapshot snapshot) {
            for (DataSnapshot postSnapshot : snapshot.getChildren()) {
                //Getting the data from snapshot 
                Person person = postSnapshot.getValue(Person.class);
               mAdapter.add(person);
    

    【讨论】:

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