我必须使用firebase在android中开发一个聊天应用程序，它包含不同的组，可以选择离开和加入组，第一次它不显示已加入和已离开的组，但第二次滚动列表视图或更改视图，然后它显示正确。我必须修复问题，请查看下面的代码，并显示应修复哪些问题。
public class Allgroups extends AppCompatActivity {
private DatabaseReference mDatabaseRef;
private List<ImageUpload> imgList;
private List<groupuserstoken> imgList1;
ListView listView;
private ImageListAdapter adapter;
private DatabaseReference databaseReference;
ProgressDialog progressDialog;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_allgroups);
progressDialog = new ProgressDialog(this);
progressDialog.setMessage("Please wait loading groups...");
listView=(ListView)findViewById(R.id.allgroups11);
mDatabaseRef = FirebaseDatabase.getInstance().getReference();
imgList=new ArrayList<>();
final Query query = mDatabaseRef.child("Groups");
listView.smoothScrollByOffset(10);
query.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
for (DataSnapshot snapshot : dataSnapshot.getChildren()) {
ImageUpload img = snapshot.getValue(ImageUpload.class);
imgList.add(img);
}
adapter = new ImageListAdapter(Allgroups.this, R.layout.custommenu, imgList);
adapter.notifyDataSetChanged();
listView.setAdapter(adapter);
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
String name=imgList.get(i).getName();
String path=imgList.get(i).getUrl();
String topic=imgList.get(i).getTopic();
Intent intent= new Intent(getApplicationContext(),Main4Activity.class);
intent.putExtra("name",name);
intent.putExtra("path",path);
intent.putExtra("topic",topic);
startActivity(intent);
}
});
}
}
public class ImageListAdapter extends ArrayAdapter<ImageUpload> {
private Activity context;
private int resource;
private List<ImageUpload> listImage;
private DatabaseReference mDatabaseRef;
private List<groupuserstoken> imgList1;
ProgressDialog progressDialog;
int pos;
public ImageListAdapter(@NonNull Activity context, @LayoutRes int resource, @NonNull List<ImageUpload> objects) {
super(context, resource, objects);
this.context = context;
this.resource = resource;
listImage = objects;
}
TextView tvName;
TextView tvDes;
TextView statuss;
Button leave;
ImageView img;
@NonNull
@Override
public View getView(final int position, @Nullable View convertView, @NonNull ViewGroup parent) {
View v = convertView;
if (v == null) {
LayoutInflater vi;
vi = LayoutInflater.from(getContext());
v = vi.inflate(R.layout.custommenu, null);
}
// final LayoutInflater inflater = context.getLayoutInflater();
// v = LayoutInflater.from(getContext()).inflate(R.layout.custommenu, parent, false);
ImageUpload listImage1 = getItem(position);
if (listImage1 !=null) {
tvName = (TextView) v.findViewById(R.id.as);
tvDes = (TextView) v.findViewById(R.id.aa);
statuss = (TextView) v.findViewById(R.id.users);
img = (ImageView) v.findViewById(R.id.addgroup1);
leave = (Button) v.findViewById(R.id.leavegroup);
mDatabaseRef = FirebaseDatabase.getInstance().getReference();
final String name = listImage.get(pos).getName();
final Query query1 = mDatabaseRef.child(name + "user");
query1.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
imgList1 = new ArrayList<>();
for (DataSnapshot snapshot : dataSnapshot.getChildren()) {
groupuserstoken img = snapshot.getValue(groupuserstoken.class);
imgList1.add(img);
}
String token = FirebaseInstanceId.getInstance().getToken();
if (!(imgList1.isEmpty())) {
if (!(imgList1.contains(token))) {
leave.setText("Leave Group");
}
}
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
tvName.setText(listImage1.getName());
tvDes.setText(listImage1.getDescription());
statuss.setText(listImage1.getMembers() + " Users ");
Glide.with(context).load(listImage1.getUrl()).into(img);
}
leave.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
String groupname = listImage.get(position).getName();
mDatabaseRef = FirebaseDatabase.getInstance().getReference().child(groupname+"user").child(FirebaseInstanceId.getInstance().getToken());
mDatabaseRef.child("token").setValue(FirebaseInstanceId.getInstance().getToken());
}
});
return v;
}
}
答案 0 :(得分：0)
请在适配器中使用setTag()和getTag()，但为了更好的做法，请使用RecyclerView代替ListView。