我已经用TextView和ImageView创建了一个Place对象，但是当我尝试添加一个place对象时出现此错误

Question

Whenever I try to add an item to the object it gives an error

I tried to switch between android.support.v4.app and the other one but it is not working

Code of Place Object

package com.example.tourguide.ui.main;
public class Place {


/** String resource ID for the name of the place */
private int mDefaultTranslationId;

private int mImageResourceId;

public Place(int defaultTranslationId, int imageResourceId) {
    mDefaultTranslationId = defaultTranslationId;
    mImageResourceId = imageResourceId;
}

/**
 * Get the string resource ID for the name of the place.
 */
public int getPlaceName() {
    return mDefaultTranslationId;
}

/**
 * Return the image resource ID of the place.
 */
public int getImageResourceId() {
    return mImageResourceId;
}

}

Code of Place Adapter

package com.example.tourguide.ui.main;

import android.content.Context;
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 com.example.tourguide.R;

import java.util.ArrayList;

public class PlaceAdapter extends ArrayAdapter<Place> {

public PlaceAdapter(Context context, ArrayList<Place> places) {
    super(context, 0, places);
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    // Check if an existing view is being reused, otherwise inflate the 
view
    View listItemView = convertView;
    if (listItemView == null) {
        listItemView = LayoutInflater.from(getContext()).inflate(
                R.layout.list_item, parent, false);
    }


    Place currentPlace = getItem(position);

    TextView placeName = (TextView) 
listItemView.findViewById(R.id.ImageViewText);

    placeName.setText(currentPlace.getPlaceName ());

    ImageView imageView = (ImageView) 
listItemView.findViewById(R.id.ImageView);

        imageView.setImageResource ( currentPlace.getImageResourceId () );

    return listItemView;
}

}

This is where I am getting an error when I try to add an item in Place object

package com.example.tourguide.ui.main;


import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ListView;

import androidx.fragment.app.Fragment;

import com.example.tourguide.R;

import java.util.ArrayList;

public class MonumentsFragment extends Fragment {

public MonumentsFragment() {
    // Required empty public constructor
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    View rootView = inflater.inflate( R.layout.places_list, container, 
  false);

    final ArrayList<Place> places = new ArrayList<> ();

    places.add(R.string.app_name, R.drawable.google_maps);


    PlaceAdapter adapter = new PlaceAdapter (getActivity(), places);

    ListView listView = (ListView) rootView.findViewById(R.id.list);

    listView.setAdapter(adapter);


    listView.setOnItemClickListener(new AdapterView.OnItemClickListener() 
{
        @Override
        public void onItemClick(AdapterView<?> adapterView, View view, int 
position, long l) {

            Place place = places.get(position);
        }
    });

    return rootView;

    }
}

This is the error message that i am getting

Wrong 2nd argument type. Found: 'int', required: 'com.example.tourguide.ui.main.Place' Inspection info: add (int, com.example.tourguide.ui.main.Place) in ArrayList cannot be applied to (int, int)

Answer 1

You're trying to add name and the image to list directly. What you should do is first create a Place Object and then add this to the list.

ArrayList<Place> places = new ArrayList<> ();
// create a Place Object
Place place = new Place(R.string.app_name, R.drawable.google_maps)
// Then add the object to the list
places.add(place);

EDIT

You can add any type of data to a List, but it has to be the same type as you declare when initializing the array. For example, you are making a List of Places and therefore you can only add Place Object to the array.

The add method takes two parameters, first the index and then the object. If you just use list.add(E element) it will append the Object to the end of the list.

public void add(int index, E element)

Inserts the specified element at the specified position in this list. Shifts the element currently at that position (if any) and any subsequent elements to the right (adds one to their indices).

You can find more about ArrayList from this doc