通过Gridview android传递选中的项目

如何解决通过Gridview android传递选中的项目

我有一个自定义网格适配器，正在尝试使用按钮检查已检查到另一个活动的项目。我试图通过将选中的项目添加到 ArrayList 来做到这一点。

这是我的 MainActivity 中按钮的 onClick 部分：

button.setonClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //String[] URLItem = gridAdapter.getURL();
                for(int i = 0; i < gridAdapter.getCount(); i++){
                    if(gridAdapter.isChecked()){
                        //checkedURL.add(fullURL[i]);
                        checkedURL.add(gridAdapter.getItem(i));
                    }
                }
Intent selIntent = new Intent(getApplicationContext(),SelectedLocations.class);
                    selIntent.putStringArrayListExtra(selKey,checkedURL);
                    //selIntent.putExtra(selKey,selURL);
                    startActivity(selIntent);

这是我的自定义适配器：

package com.example.placesofinterest;

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.graphics.Bitmap;
import android.media.ThumbnailUtils;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.CheckBox;
import android.widget.GridView;
import android.widget.ImageView;

import androidx.recyclerview.widget.RecyclerView;

import com.android.volley.VolleyError;
import com.android.volley.toolBox.ImageLoader;

import java.util.ArrayList;

public class GridAdapter extends BaseAdapter {

    private Context context;
    private String[] url;
    private ArrayList<String> checkedURL;
    private boolean checked;

    public boolean isChecked() {
        return checked;
    }

    public  ArrayList<String> getCheckedURL() { return checkedURL;    }

    public GridAdapter(Context c,String[] url){
        this.context = c;
        this.url = url;
    }

    @Override
    public int getCount() {
        return url.length;
    }

    @Override
    public String getItem(int position) {
        return url[position];
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position,View convertView,ViewGroup parent) {
        LayoutInflater inflater;
        if (convertView == null) {
            inflater = LayoutInflater.from(context);
            ImageLoader imageLoader = MySingleton.getInstance(context.getApplicationContext()).getimageLoader();

            if (context instanceof MainActivity){
                convertView = inflater.inflate(R.layout.places_layout,parent,false);
            }
            else if (context instanceof SelectedLocations){
                convertView = inflater.inflate(R.layout.selected_layout,false);
            }

            final View finalConvertView = convertView;
            imageLoader.get(url[position],new ImageLoader.ImageListener() {
                @Override
                public void onResponse(ImageLoader.ImageContainer response,boolean isImmediate)
                {
                    Bitmap image = response.getBitmap();
                    Bitmap thumbnail = ThumbnailUtils.extractThumbnail(image,250,250);

                    if (context instanceof MainActivity) {
                        ImageView imageView = finalConvertView.findViewById(R.id.imageView);
                        imageView.setimageBitmap(thumbnail);
                        CheckBox checkBox = (CheckBox) finalConvertView.findViewById(R.id.checkBox);
                        checked = checkBox.isChecked();
                        if(checked){
                            checkedURL.add(url[position]);
                            checked = true;
                        }else {
                            //checkedURL.remove(URL[position]);
                            checked = false;

                        }
                    }
                    else if (context instanceof SelectedLocations){
                        ImageView selImg = finalConvertView.findViewById(R.id.selImg);
                        selImg.setimageBitmap(thumbnail);
                    }
                }

                @Override
                public void onErrorResponse(VolleyError error)
                {
                    System.out.println(error.getMessage());
                }
            });
        }


        return convertView;
    }

}

如果您需要其他任何东西，这是我的 MainActivity 的其余部分！

package com.example.placesofinterest;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.graphics.Bitmap;
import android.media.ThumbnailUtils;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.GridView;
import android.widget.Toast;

import com.android.volley.VolleyError;
import com.android.volley.toolBox.ImageLoader;

import java.util.ArrayList;

import static android.provider.Contacts.SettingsColumns.KEY;

public class MainActivity extends AppCompatActivity {
    GridView gridView;
    GridAdapter gridAdapter;
    ArrayList<String> checkedURL = new ArrayList<String>();
    Button button;

    String selKey = "Selected";
    String fullImg = "Image";
    String locName = "Location";

    private String fullURL[] = {"http://192.168.0.105/places/amsterdam.png","http://192.168.0.105/places/bali.png","http://192.168.0.105/places/dubai.png","http://192.168.0.105/places/germany.png","http://192.168.0.105/places/cambodia.png","http://192.168.0.105/places/ireland.png","http://192.168.0.105/places/japan.png","http://192.168.0.105/places/prague.png","http://192.168.0.105/places/sweden.png"};

    private String location[] = { "Amsterdam","Bali","dubai","Germany","Cambodia","Ireland","Japan","Sweden","Prague"};

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

        gridView = findViewById(R.id.grid);
        gridAdapter = new GridAdapter(MainActivity.this,fullURL);
        gridView.setAdapter(gridAdapter);

        button = findViewById(R.id.button);
        button.setonClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //checkGridView(gridView);
                //checkedURL = gridAdapter.getCheckedURL();
                //String[] URLItem = gridAdapter.getURL();
                for(int i = 0; i < gridAdapter.getCount(); i++){
                    if(gridAdapter.isChecked()){
                        //checkedURL.add(fullURL[i]);
                        checkedURL.add(gridAdapter.getItem(i));
                    }
                }
                //checkedURL = gridAdapter.getCheckedURL();
                //String[] selURL = checkedURL.toArray(new String[0]);
                //String[] selURL = fullURL;
                    Intent selIntent = new Intent(getApplicationContext(),selURL);
                    startActivity(selIntent);

            }
        });

        gridView.setonItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent,View view,int position,long id) {
                //String imgLoc = location[gridAdapter.getCount() - position - 1];
                Intent imgIntent = new Intent(MainActivity.this,ImageActivity.class);
                //imgIntent.putExtra(fullImg,clickImg);
                String clickURL = fullURL[position];
                String imgLoc = location[position];
                imgIntent.putExtra(fullImg,clickURL);
                imgIntent.putExtra(locName,imgLoc);
                startActivity(imgIntent);
            }
        });
    }
}