Question

我不知道Firebase和Arduino .... 但我写了这段代码，指的是David East的视频。所以我收到了错误，请帮我解决。

错误是：

错误：（66,52）错误：找不到适合FirebaseListAdapter（）的构造函数构造函数FirebaseListAdapter.FirebaseListAdapter（Activity，Class，int，Firebase）不适用（实际和正式的参数列表长度不同）构造函数FirebaseListAdapter.FirebaseListAdapter（Activity，Class，int，Query）不适用（实际和正式的参数列表长度不同）

这是MainActivity.java的代码：

package com.example.devashish.sprout;

import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TextView;

import com.firebase.client.ChildEventListener;
import com.firebase.client.DataSnapshot;
import com.firebase.client.Firebase;
import com.firebase.client.FirebaseError;
import com.firebase.client.ValueEventListener;
import com.firebase.ui.FirebaseListAdapter;

import java.util.ArrayList;
import java.util.Map;
import java.util.Objects;

public class MainActivity extends AppCompatActivity {

Firebase mRootRef;
ArrayList<String> mMessages= new ArrayList<>();

TextView mTextView;
ListView mListView;



@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);

    FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
    fab.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                    .setAction("Action", null).show();
        }
    });
}

@Override
protected void onStart(){
    super.onStart();



    mTextView=(TextView)findViewById(R.id.textViewCondition);
    mListView=(ListView)findViewById(R.id.listView);

    mRootRef = new Firebase("https://pleaserun.firebaseio.com");
    Firebase messagesRef=mRootRef.child("condition");
    final FirebaseListAdapter<String> adapter= new FirebaseListAdapter<String>() {
        @Override
        protected void populateView(View view, String s, int i) {
            TextView textView=(TextView)view.findViewById(android.R.id.text1);
            textView.setText(s);
            mListView.setAdapter(adapter);
        }
    };



}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}
}

我将您提到的行更改为：final FirebaseListAdapter adapter = new FirebaseListAdapter（this，String.class，android.R.layout.simple_list_item_1，messagesRef）

现在给出错误：错误：（71,38）错误：变量适配器可能尚未初始化

Answer 1

您缺少FirebaseListAdapter所需的构造函数参数。在你的情况下可能是这样的：

final FirebaseListAdapter<String> adapter= new FirebaseListAdapter<String>(
  this,         /* the activity */
  String.class, /* the data type that you're reading from Firebase */
  android.R.layout.two_line_list_item, /* the layout for each item */
  messagesRef   /* the Query/Firebase location to read the data from */
) {
  ...

请注意，在相关的documented in the FirebaseUI repo或Android Studio的错误消息中，这一切都非常合理FirebaseUI codelab。

Answer 2

问题在于firebaseui依赖关系，请使用此

compile 'com.firebaseui:firebase-ui:0.3.1'

我有同样的问题，一旦我改变了错误就消失了。删除当前的firebaselistadapter代码并重新写入。祝你好运

Android

2 个答案: