如何在 Android Studio 中设置 FirebaseAdapter？

Question

我正在尝试将数据从 Firebase 实时读取到自定义 ArrayAdapter。根据我的研究，FirebaseListAdapter 似乎内置了处理此问题的功能。但是，我无法让我的代码识别 FirebaseListAdapter 类。如何让 FirebaseListAdapter 工作？

Gradle 文件

    apply plugin: 'com.android.application'

android {
    compileSdkVersion 24
    buildToolsVersion "24.0.0"

    defaultConfig {
        applicationId "com.example.quizzingcompanion"
        minSdkVersion 15
        targetSdkVersion 24
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(include: ['*.jar'], dir: 'libs')
    testCompile 'junit:junit:4.12'
    compile 'com.google.firebase:firebase-database:9.6.0'
    compile 'com.google.firebase:firebase-core:9.6.0'
    compile 'com.google.firebase:firebase-auth:9.6.0'
    compile 'com.android.support:appcompat-v7:24.1.1'
    compile 'com.android.support:design:24.1.1'
    compile 'com.android.support:support-v4:24.1.1'
    compile 'com.firebase:firebase-client-android:2.3.1'
    compile 'com.firebaseui:firebase-ui:0.6.0'
    compile 'com.firebaseui:firebase-ui-storage:0.6.0'
    compile 'com.firebaseui:firebase-ui-database:0.6.0'
}

apply plugin: 'com.google.gms.google-services'

FirebaseAdapter 初始化

FirebaseListAdapter<Participant> adapter = new FirebaseListAdapter;

错误信息

Failed to resolve: com.google.firebase:firebase-auth:9.6.0
Failed to resolve: com.google.firebase:firebase-storage:9.6.0
Failed to resolve: com.google.firebase:firebase-database:9.6.0
Failed to resolve: com.google.android.gms:play-services-auth:9.6.0
Cannot resolve symbol FirebaseListAdapter

带列表的片段

import android.content.Intent;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ListView;

import java.util.ArrayList;

/**
 * A simple {@link Fragment} subclass.
 */
public class ParticipantFragment extends Fragment {
    private DataSource data;
    DatabaseReference database;
    ArrayList<Participant> participants = new ArrayList<>();

    public ParticipantFragment() {
        data = new DummyDataSource();
        database = FirebaseDatabase.getInstance().getReference();
    }


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {

        final View rootView = inflater.inflate(R.layout.content_participants_fragment, container, false);

        FirebaseListAdapter<Participant> adapter = new FirebaseListAdapter;
        ListView listView = (ListView) rootView.findViewById(R.id.participants_list);
        ParticipantAdapter adapter = new ParticipantAdapter(getActivity(), data.getParticipants());
        listView.setAdapter(adapter);

        FloatingActionButton fab = (FloatingActionButton) rootView.findViewById(R.id.participants_fab);
        fab.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                Intent intent = new Intent(getContext(), NewParticipant.class);
                startActivity(intent);
            }
        });}

自定义适配器

import android.app.Activity;
import android.media.Image;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.TextView;

import java.util.ArrayList;

/**
 * Created by Tim on 9/10/2016.
 */
public class ParticipantAdapter extends ArrayAdapter {
    public ParticipantAdapter(Activity context, ArrayList<Participant> participant) {
        super(context, 0, participant);
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        View listItemView = convertView;
        if(listItemView == null){
            listItemView = LayoutInflater.from(getContext()).inflate(R.layout.participants_list_item, parent, false);
        }

        Participant currentParticipant = (Participant) getItem(position);

        ImageView participantImage = (ImageView) listItemView.findViewById(R.id.participant_image);
        if(currentParticipant.hasImageValue()){
            participantImage.setImageResource(currentParticipant.getImageID());
        }else{
            participantImage.setImageResource(R.drawable.ic_my_profile);
        }

        TextView name = (TextView) listItemView.findViewById(R.id.participant_name);
        name.setText(currentParticipant.getDisplayName());

        ImageView image = (ImageView) listItemView.findViewById(R.id.participant_role);
        switch (currentParticipant.getRole()){
            case "Official": image.setImageResource(R.drawable.ic_official);
            case "Spectator": image.setImageResource(R.drawable.ic_spectator);
            case "Quizzer": image.setImageResource(R.mipmap.ic_quizzer);
            default: image.setVisibility(View.GONE);
        }

        return listItemView;
    }
}

添加值的位置

Button okBtn = (Button) findViewById(R.id.add_participant);
        okBtn.setOnClickListener(new View.OnClickListener() {
            @Override

            public void onClick(View view) {
                DatabaseReference ref = database.child("participants");
                EditText firstName = (EditText)  findViewById(R.id.first_name);
                EditText lastName = (EditText)  findViewById(R.id.last_name);
                Participant newParticipant = new Participant(firstName.getText().toString(),
                                                                lastName.getText().toString(),
                                                                sp.getSelectedItem().toString(),
                                                                sp2.getSelectedItem().toString());
                Map<String, Object> participantValues = newParticipant.toMap();
                ref.push().setValue(participantValues);
            }
        });

Answer 1

FirebaseUI readme 有这个方便的compatibility table：

FirebaseUI  Firebase/Play 
 Version    Services Version
   1.2.0       10.2.0
   1.1.1       10.0.0 or 10.0.1
   1.0.1       10.0.0 or 10.0.1
   1.0.0       9.8.0
   0.6.2       9.8.0
   0.6.1       9.6.1
   0.6.0       9.6.0
   0.5.3       9.4.0
   0.4.4       9.4.0
   0.4.3       9.2.1
   0.4.2       9.2.0
   0.4.1       9.0.2
   0.4.0       9.0.0

因此，要使用 FirebaseUI 0.6，您必须使用 Firebase/Play Services SDK 9.6。如果您想使用 Firebase/Play Services SDK 9.4，则必须使用 FirebaseUI 0.5。

此外，您还缺少列表适配器的导入语句：

import com.firebase.ui.database.FirebaseListAdapter;

Android Studio 应该已经为您提供了有关此导入的提示。

Answer 2

也许您可以将 Firebase 依赖项更改为最新版本。

compile 'com.google.firebase:firebase-database:9.6.0'
compile 'com.google.firebase:firebase-core:9.6.0'
compile 'com.google.firebase:firebase-auth:9.6.0'