我无法使FirebaseListAdapter适用于我的应用程序

Question

根据我在envatotuts+上找到的教程，我正在开发一个Android群组聊天应用程序，除了FirebaseListAdapter之外，一切看起来都很好。该项目拒绝编译，它提供此错误Error:(18, 32) error: package com.firebase.ui.database does not exist，在进行下面建议的更正后，错误消失，此错误弹出Error:(133, 19) error: cannot find symbol constructor (DatabaseReference,Class<ChatMessage>,int,MainActivity)。附件是MainActivity.java文件和我的activityMain.xml文件。

MainActivity.java

package com.abdul.friendsdemo;

import android.content.Intent;
import android.icu.text.DateFormat;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.design.widget.FloatingActionButton;
import android.support.v7.app.AppCompatActivity;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

import com.firebase.ui.auth.AuthUI;
import com.firebase.ui.database.FirebaseListAdapter;
import com.google.android.gms.tasks.OnCompleteListener;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.database.FirebaseDatabase;

import java.util.Calendar;


public class MainActivity extends AppCompatActivity {

    private FirebaseListAdapter<ChatMessage> adapter;
    private static final int SIGN_IN_REQUEST_CODE = 123;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        if(FirebaseAuth.getInstance().getCurrentUser() == null){
            //Start sign in/sign up activity
            startActivityForResult(AuthUI.getInstance()
                    .createSignInIntentBuilder()
                    .build(), SIGN_IN_REQUEST_CODE);
        }else

        {
            // User is already signed in. Therefore, display
            //a welcome Toast
            Toast.makeText(this, "Welcome"
                            + FirebaseAuth.getInstance()
                            .getCurrentUser()
                            .getDisplayName(),
                    Toast.LENGTH_LONG)
                    .show();

            // Load chat room contents
            displayChatMessage();
        }


        FloatingActionButton fab =
                (FloatingActionButton) findViewById(R.id.fab);

        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                EditText input = (EditText) findViewById(R.id.input);

                //Read the input field and push a new instance
                //of ChatMessage to the Firebase database
                FirebaseDatabase.getInstance()
                        .getReference().push()
                        .setValue(new ChatMessage(input.getText().toString(),
                                FirebaseAuth.getInstance()
                                        .getCurrentUser()
                                        .getDisplayName())
                        );

                //Clear the input
                input.setText("");
            }
        });
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode,
                                    Intent data){
        super.onActivityResult(requestCode, resultCode, data);

        if(requestCode == SIGN_IN_REQUEST_CODE){
            if(resultCode ==RESULT_OK){
                Toast.makeText(this, "Successfully signed in. Welcome!",
                        Toast.LENGTH_LONG).show();
                displayChatMessage();
            }else{
                Toast.makeText(this, "We couldn't sign you in. Please try again later.",
                        Toast.LENGTH_LONG).show();
                //Close the app
                finish();
            }
        }
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.main_menu, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        if (item.getItemId() == R.id.sign_out) {
            AuthUI.getInstance().signOut(this)
                    .addOnCompleteListener(new OnCompleteListener<Void>() {
                        public void onComplete(@NonNull Task<void> task) {
                            Toast.makeText(MainActivity.this,
                                    "You have been signed out.",
                                    Toast.LENGTH_LONG).show();
                            startActivity(new Intent(MainActivity.this,
                                    AuthUI.class));
                            // Close activity;
                            finish();
                        }
                    });

        }
        return true;
    }

    private void displayChatMessage() {

        ListView listOfMessages = (ListView) findViewById(R.id.list_of_messages);

        adapter = new FirebaseListAdapter<Chatmessage>(this, ChatMessage.class,
                R.layout.messages, FirebaseDatabase.getInstance().getReference()) {
            @Override
            protected void populateView(View v, ChatMessage model, int position) {
                //Get references to the views of messages.xml
                TextView messageText = (TextView) v.findViewById(R.id.message_body);
                TextView messageUser = (TextView) v.findViewById(R.id.message_user);
                TextView messageTime = (TextView) v.findViewById(R.id.message_time);

                // Set their text
                messageText.setText(model.getMessageText());
                messageUser.setText(model.getMessageUser());

                //Format the date before showing it
                Calendar c = Calendar.getInstance();
                int hour = c.get(Calendar.HOUR);
                int minute = c.get(Calendar.MINUTE);
                messageTime.setText(hour + ":" + minute);
            }
        };

        listOfMessages.setAdapter(adapter);
    }

}

和activityMain.xml文件

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.abdul.friendsdemo.MainActivity">

    <android.support.design.widget.FloatingActionButton
        android:id="@+id/fab"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_alignParentEnd="true"
        android:layout_alignParentRight="true"
        android:clickable="true"
        android:src="@drawable/ic_send_black_24dp"
        android:tint="@android:color/white"
        app:fabSize="mini" />

    <EditText
        android:id="@+id/input"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        android:layout_toLeftOf="@id/fab" />

    <ListView
        android:id="@+id/list_of_messages"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_above="@id/fab"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        android:layout_alignParentTop="true"
        android:layout_marginBottom="@dimen/activity_horizontal_margin"
        android:divider="@android:color/transparent"
        android:dividerHeight="@dimen/activity_horizontal_margin" />
</RelativeLayout>

app:build gradle

apply plugin: 'com.android.application'

android {
    compileSdkVersion 25
    buildToolsVersion "25.0.0"
    defaultConfig {
        applicationId "com.abdul.friendsdemo"
        minSdkVersion 16
        targetSdkVersion 25
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    compile 'com.android.support:design:25.0.1'
    compile 'com.android.support:appcompat-v7:25.0.1'
    compile 'com.firebaseui:firebase-ui-auth:1.2.0'
    compile 'com.google.firebase:firebase-core:10.2.0'
    compile 'com.firebaseui:firebase-ui:1.2.0'
    compile 'com.google.firebase:firebase-auth:10.2.0'
    compile 'com.google.firebase:firebase-database:10.2.0'
    testCompile 'junit:junit:4.12'
}




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

我已经尝试了很多其他问题，但是对他们有用的解决方案并不适用于我。

Answer 1

您的声明订单有误。这样：

adapter = new FirebaseListAdapter<Chatmessage>(this, ChatMessage.class,
            R.layout.messages, FirebaseDatabase.getInstance().getReference())...

应该是：

adapter = new FirebaseListAdapter<Chatmessage>(FirebaseDatabase.getInstance().getReference(), ChatMessage.class,
            R.layout.messages,this )

这是基于文档here。您可以看到构造函数是：public FirebaseListAdapter(Query mRef, Class<T> mModelClass, int mLayout, Activity activity) {

您在最后一个参数处有参考，而不是第一个参数。活动应该是最后一次。

Answer 2

如果有人仍然遇到此问题，请使用此功能。

Query query = FirebaseDatabase.getInstance().getReference();
FirebaseListOptions<ChatMessage> options = new FirebaseListOptions.Builder<ChatMessage>()
            .setQuery(query, ChatMessage.class)
            .build();
adapter = new FirebaseListAdapter<ChatMessage>(options) {
        @Override
        protected void populateView(View v, ChatMessage model, int position) {

        }
    };

Answer 3

你有没有添加

compile 'com.firebaseui:firebase-ui:x.x.x'

在您的gradle文件中

并同步？

请参阅Firebase UI Installation

Answer 4

以下解决方案对我有帮助。其他人可能会尝试使用它。

 private void displayChatMessage(){
        ListView listOfMessage = (ListView) findViewById ( R.id.list_of_message );
        Query query = FirebaseDatabase.getInstance().getReference().child("chats");

        FirebaseListOptions<ChatMessage> options =
                new FirebaseListOptions.Builder<ChatMessage>()
                        .setQuery(query, ChatMessage.class)
                        .setLayout(android.R.layout.simple_list_item_1)
                        .build();
        adapter = new FirebaseListAdapter<ChatMessage>(options){
            @Override
            protected void populateView(@NonNull View v, @NonNull ChatMessage model, int position) {
                TextView messageText, messageUser, messageTime;
                messageText = v.findViewById ( R.id.message_text );
                messageUser = v.findViewById ( R.id.message_user );
                messageTime = v.findViewById ( R.id.message_time );

                messageText.setText ( model.getMessageText () );
                messageUser.setText ( model.getMessageUser () );
                messageTime.setText ( DateFormat.format("dd-MM-yyyy(HH:mm:ss)", model.getMessageTime ()) );
            }
        };
        listOfMessage.setAdapter ( adapter );
    }