没有警告的设置器/字段Firebase数据库检索数据填充Listview [英] No setter/field for warning Firebase Database Retrieve Data Populate Listview
问题描述
我只是试图将Firebase数据库中的数据填充到我的列表视图中.日志显示正在检索数据，但是适配器不会将值设置为列表中单个列表项中的文本吗?它只说没有插入值的设置器/字段".这让我认为我没有正确地创建设置器，但是Android Studio自动生成了这些设置器.我不知道我在这里想念的是什么.任何帮助表示赞赏.
I'm simply just trying to populate data from Firebase Database into my listview. The logs are showing the data is being retrieved, but the adapter won't set the values to the text in a single list item in the list? All it says is "No setter/field for INSERT VALUE". Which makes me think that I didn't have my setters made correctly but there were auto generated by Android Studio. I don't know what I am missing here. Any help is appreciated.
节点对象
package com.megliosolutions.ipd.Objects;
import android.graphics.Bitmap;
/**
* Created by Meglio on 6/13/16.
*/
public class NodeObject {
public String mStaticAddress;
public String mLat;
public String mLong;
public NodeObject(){
//needed for firebase
}
public NodeObject(String address, String lat, String Long){
this.mStaticAddress = address;
this.mLat = lat;
this.mLong = Long;
}
public String getmStaticAddress() {
return mStaticAddress;
}
public void setmStaticAddress(String mStaticAddress) {
this.mStaticAddress = mStaticAddress;
}
public String getmLat() {
return mLat;
}
public void setmLat(String mLat) {
this.mLat = mLat;
}
public String getmLong() {
return mLong;
}
public void setmLong(String mLong) {
this.mLong = mLong;
}
}
静态列表适配器
/**
* Created by Meglio on 6/14/16.
*/
public class StaticListAdapter extends ArrayAdapter<NodeObject> {
public static String TAG = StaticListAdapter.class.getSimpleName();
public Context mContext;
public List<NodeObject> mNodes;
public class ViewHolder {
TextView mStaticAddress;
TextView mLAT;
TextView mLONG;
}
@Override
public int getCount() {
return mNodes.size();
}
public StaticListAdapter(Context context, List<NodeObject> objects) {
super(context, R.layout.activity_main, objects);
this.mContext = context;
this.mNodes = objects;
}
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder = new ViewHolder();
NodeObject node = mNodes.get(position);
if (convertView == null) {
convertView = LayoutInflater.from(this.mContext).inflate(R.layout.node_item, null);
holder.mLONG = (TextView) convertView.findViewById(R.id.node_item_LONG);
holder.mStaticAddress = (TextView) convertView.findViewById(R.id.node_item_IP);
holder.mLAT = (TextView) convertView.findViewById(R.id.node_item_LAT);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
holder.mStaticAddress.setText(node.getStaticAddress());
holder.mLONG.setText(node.getLongitude());
holder.mLAT.setText(node.getLatitude());
return convertView;
}
}
维护性
public class MainActivity extends AppCompatActivity {
public static String TAG = MainActivity.class.getSimpleName();
public ListView main_ListView;
public FirebaseAuth mAuth;
public FirebaseUser mUser;
public DatabaseReference mDatabase;
//Strings
public String static_ip;
public String lat = "5.0";
public String mLong = "4.0";
public String currentUser;
//Adapters
public StaticListAdapter listAdapter;
//Node Object
NodeObject node;
public List<NodeObject> nodesList;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//Instances
mAuth = FirebaseAuth.getInstance();
mUser = mAuth.getCurrentUser();
mDatabase = FirebaseDatabase.getInstance().getReference();
currentUser = mUser.getUid();
main_ListView = (ListView)findViewById(R.id.Main_listview);
//Toolbar
if (getSupportActionBar() != null) {
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
}
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
//[End of Toolbar]
nodesList = new ArrayList<>();
retrieveData();
listAdapter = new StaticListAdapter(getApplicationContext(),nodesList);
main_ListView.setAdapter(listAdapter);
Log.i(TAG, "USER: " + currentUser);
}
private void retrieveData() {
mDatabase.child("nodes").child(mUser.getUid())
.addChildEventListener(new ChildEventListener() {
@Override
public void onChildAdded(DataSnapshot dataSnapshot, String s) {
Log.d(TAG, "onChildAdded:" + dataSnapshot.getKey());
NodeObject nodeObject = dataSnapshot.getValue(NodeObject.class);
listAdapter.add(nodeObject);
listAdapter.setNotifyOnChange(true);
}
@Override
public void onChildChanged(DataSnapshot dataSnapshot, String s) {
}
@Override
public void onChildRemoved(DataSnapshot dataSnapshot) {
}
@Override
public void onChildMoved(DataSnapshot dataSnapshot, String s) {
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle item selection
switch (item.getItemId()) {
case R.id.getGPS:
//nothing
return true;
case R.id.addNode:
addNode();
return true;
case R.id.logout:
signOut();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
private void signOut() {
mAuth.signOut();
Intent intent = new Intent(MainActivity.this, Login.class);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
Toast.makeText(getApplicationContext(), "Logging Out.", Toast.LENGTH_SHORT).show();
startActivity(intent);
}
private void addNode() {
//AlertDialog
final AlertDialog.Builder dialogBuilder = new AlertDialog.Builder(this);
dialogBuilder.setTitle("Dude, assign something...");
LayoutInflater inflater = this.getLayoutInflater();
View dialogView = inflater.inflate(R.layout.main_add_node_dialog, null);
dialogBuilder.setView(dialogView);
final EditText editText = (EditText)
dialogView.findViewById(R.id.static_et);
dialogBuilder.setPositiveButton("Assign", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
static_ip = editText.getText().toString();
String ip = static_ip;
node = new NodeObject(ip, lat, mLong);
mDatabase.child("nodes").child(currentUser).push().setValue(node);
Toast.makeText(getApplicationContext(), "Static IP: " + static_ip + " assigned!"
, Toast.LENGTH_SHORT).show();
}
}).
setNegativeButton("Or Not...", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
Toast.makeText(getApplicationContext(), "Fine, nvm then..."
, Toast.LENGTH_SHORT).show();
}
});
dialogBuilder.create().show();
}
}
调试显示我可以得到客户端的所有信息.日志也显示了这一点.
Debugging shows that I am able to get everything client side. Logs show this as well.
06-18 18:25:42.981 12962-12962/com.megliosolutions.ipd D/MainActivity: zHF4TGnRvkeXEbKiLegiUNLGHX12:{-KKLeBAe9pV1Umm3qQMo={mStaticAddress=26161910494949, mLong=3.0, mLat=2.0}, -KKG_ACFvdX7aJOR98-o={mStaticAddress=10.223.22.250, mLong=3.0, mLat=2.0}, -KKWKMZS7WkE_xWbL3rC={mStaticAddress=, mLong=4, mLat=5}, -KKQQLITf9-7iMFlqEWR={mStaticAddress=123123123123, mLong=3.0, mLat=2.0}, -KKG_J6PKwogjBFdk52Z={mStaticAddress=10.333.555.888, mLong=3.0, mLat=2.0}}
更新
对我来说没有意义的部分，但是我相信对那些非常了解它的人是有意义的.正在理解我正在阅读的firebase文档.我读了几次，但我想它只是没有点击.我发现在Firebase中构造数据是 KEY .没有它，您将无法正确编码，因为一切都依赖于此.现在，我发现 Firebase 使它易于使用.我将为此写一篇博客文章，以解释我的麻烦以及如何克服这些麻烦，因此没有人会遇到这种麻烦.下面的代码将使用Firebase后端构建一个功能列表视图！
The part that didn't make sense to me, but I'm sure makes sense to those who know it very well. Is comprehending what I'm reading the firebase documentation. I read over it a few time, but I guess it just wasn't clicking. I figured out that structuring the data in firebase is KEY. Without that you can't code properly because everything relies on that. Firebase makes it easy to use now that I see it working. I will be making a blog post on this to explain my troubles and how to surpass them so no one else runs into this mess. The below code will build a functional listview with firebase backend!
public void onChildAdded(DataSnapshot dataSnapshot, String s) {
Log.d(TAG, "onChildAdded:" + dataSnapshot.getKey());
NodeObject nodeObject = dataSnapshot.getValue(NodeObject.class);
listAdapter.add(nodeObject);
listAdapter.setNotifyOnChange(true);
}
推荐答案
In retrieveData(), you should be using a ChildEventListener, not a ValueEventListener. You are adding Node objects as children of node/$uid with the keys generated by push(). The ValueEventListener is returning a Map<String,Object> containing all of the Nodes. That is shown in the logcat output you posted. You can use the onChildAdded() callback of ChildEventListener to get each Node as it is created and then add it to your adapter.
这篇关于没有警告的设置器/字段Firebase数据库检索数据填充Listview的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
