我想使用 json 将 Listview 数据发送到 Android 中的另一个 Activity

Posted 2023-05-07

【中文标题】我想使用 json 将 Listview 数据发送到 Android 中的另一个 Activity

【英文标题】：i want to send Listview Data to Another Activity in Android using json

【发布时间】：2015-12-01 10:09:17

【问题描述】：

我想将Listview 数据发送给另一个Activity。

检查我的代码：

ActorAdapter.java

package anyname;

import java.io.InputStream;
import java.util.ArrayList;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.TextView;

public class ActorAdapter extends ArrayAdapter<Actors> 
    ArrayList<Actors> actorList;
    LayoutInflater vi;
    int Resource;
    ViewHolder holder;

    public ActorAdapter(Context context, int resource, ArrayList<Actors> objects) 
        super(context, resource, objects);
        vi = (LayoutInflater) context
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        Resource = resource;
        actorList = objects;
    


    @Override
    public View getView(int position, View convertView, ViewGroup parent) 
        // convert view = design
        View v = convertView;
        if (v == null) 
            holder = new ViewHolder();
            v = vi.inflate(Resource, null);
            holder.imageview = (ImageView) v.findViewById(R.id.ivImage);
            holder.tvName = (TextView) v.findViewById(R.id.tvName);
            holder.tvDescription = (TextView) v.findViewById(R.id.tvDescriptionn);
            holder.tvDOB = (TextView) v.findViewById(R.id.tvDateOfBirth);
            holder.tvCountry = (TextView) v.findViewById(R.id.tvCountry);
            holder.tvHeight = (TextView) v.findViewById(R.id.tvHeight);
            holder.tvSpouse = (TextView) v.findViewById(R.id.tvSpouse);
            holder.tvChildren = (TextView) v.findViewById(R.id.tvChildren);
            v.setTag(holder);
         else 
            holder = (ViewHolder) v.getTag();
        
        holder.imageview.setImageResource(R.drawable.ic_launcher);
        new DownloadImageTask(holder.imageview).execute(actorList.get(position).getImage());
        holder.tvName.setText(actorList.get(position).getName());
        holder.tvDescription.setText(actorList.get(position).getDescription());
        holder.tvDOB.setText("B'day: " + actorList.get(position).getDob());
        holder.tvCountry.setText(actorList.get(position).getCountry());
        holder.tvHeight.setText("Height: " + actorList.get(position).getHeight());
        holder.tvSpouse.setText("Spouse: " + actorList.get(position).getSpouse());
        holder.tvChildren.setText("Children: " + actorList.get(position).getChildren());
        return v;

    

    static class ViewHolder 
        public ImageView imageview;
        public TextView tvName;
        public TextView tvDescription;
        public TextView tvDOB;
        public TextView tvCountry;
        public TextView tvHeight;
        public TextView tvSpouse;
        public TextView tvChildren;

    

    private class DownloadImageTask extends AsyncTask<String, Void, Bitmap> 
        ImageView bmImage;

        public DownloadImageTask(ImageView bmImage) 
            this.bmImage = bmImage;
        

        protected Bitmap doInBackground(String... urls) 
            String urldisplay = urls[0];
            Bitmap mIcon11 = null;
            try 
                InputStream in = new java.net.URL(urldisplay).openStream();
                mIcon11 = BitmapFactory.decodeStream(in);
             catch (Exception e) 
                Log.e("Error", e.getMessage());
                e.printStackTrace();
            
            return mIcon11;
        

        protected void onPostExecute(Bitmap result) 
            bmImage.setImageBitmap(result);
        

    

Actors.java

public class Actors 

    private String name;
    private String description;
    private String dob;
    private String country;
    private String height;
    private String spouse;
    private String children;
    private String image;

    public Actors() 
        // TODO Auto-generated constructor stub
    

    public Actors(String name, String description, String dob, String country,
            String height, String spouse, String children, String image) 
        super();
        this.name = name;
        this.description = description;
        this.dob = dob;
        this.country = country;
        this.height = height;
        this.spouse = spouse;
        this.children = children;
        this.image = image;
    


    public String getName() 
        return name;
    

    public void setName(String name) 
        this.name = name;
    

    public String getDescription() 
        return description;
    

    public void setDescription(String description) 
        this.description = description;
    

    public String getDob() 
        return dob;
    

    public void setDob(String dob) 
        this.dob = dob;
    

    public String getCountry() 
        return country;
    

    public void setCountry(String country) 
        this.country = country;
    

    public String getHeight() 
        return height;
    

    public void setHeight(String height) 
        this.height = height;
    

    public String getSpouse() 
        return spouse;
    

    public void setSpouse(String spouse) 
        this.spouse = spouse;
    

    public String getChildren() 
        return children;
    

    public void setChildren(String children) 
        this.children = children;
    

    public String getImage() 
        return image;
    

    public void setImage(String image) 
        this.image = image;
    

MainActivity.java

package ANYNAME;

import java.io.IOException;
import java.util.ArrayList;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Intent;
import android.net.ParseException;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.Toast;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListView;

public class MainActivity extends Activity 

    ArrayList<Actors> actorsList;

    ActorAdapter adapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) 
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        actorsList = new ArrayList<Actors>();
        new JSONAsyncTask().execute("json link here.xml");

        ListView listview = (ListView)findViewById(R.id.list);
        adapter = new ActorAdapter(getApplicationContext(), R.layout.row, actorsList);

        listview.setAdapter(adapter);

        listview.setOnItemClickListener(new OnItemClickListener() 

            @Override
            public void onItemClick(AdapterView<?> arg0, View arg1, int position,
                    long id) 
                // TODO Auto-generated method stub
                Toast.makeText(getApplicationContext(), actorsList.get(position).getName(), Toast.LENGTH_LONG).show();              
            
        );
    


    class JSONAsyncTask extends AsyncTask<String, Void, Boolean> 

        ProgressDialog dialog;

        @Override
        protected void onPreExecute() 
            super.onPreExecute();
            dialog = new ProgressDialog(MainActivity.this);
            dialog.setMessage("Loading, please wait");
            dialog.setTitle("Connecting server");
            dialog.show();
            dialog.setCancelable(false);
        

        @Override
        protected Boolean doInBackground(String... urls) 
            try 

                //------------------>>
                HttpGet httppost = new HttpGet(urls[0]);
                HttpClient httpclient = new DefaultHttpClient();
                HttpResponse response = httpclient.execute(httppost);

                // StatusLine stat = response.getStatusLine();
                int status = response.getStatusLine().getStatusCode();

                if (status == 200) 
                    HttpEntity entity = response.getEntity();
                    String data = EntityUtils.toString(entity);


                    JSONObject jsono = new JSONObject(data);
                    JSONArray jarray = jsono.getJSONArray("actors");

                    for (int i = 0; i < jarray.length(); i++) 
                        JSONObject object = jarray.getJSONObject(i);

                        Actors actor = new Actors();

                        actor.setName(object.getString("name"));
                        actor.setDescription(object.getString("description"));
                        actor.setDob(object.getString("dob"));
                        actor.setCountry(object.getString("country"));
                        actor.setHeight(object.getString("height"));
                        actor.setSpouse(object.getString("spouse"));
                        actor.setChildren(object.getString("children"));
                        actor.setImage(object.getString("image"));

                        actorsList.add(actor);
                    
                    return true;
                

                //------------------>>

             catch (ParseException e1) 
                e1.printStackTrace();
             catch (IOException e) 
                e.printStackTrace();
             catch (JSONException e) 
                e.printStackTrace();
            
            return false;
        

        protected void onPostExecute(Boolean result) 
            dialog.cancel();
            adapter.notifyDataSetChanged();
            if(result == false)
                Toast.makeText(getApplicationContext(), "Unable to fetch data from server", Toast.LENGTH_LONG).show();

        
    

当用户点击 Listview 内容并将 Listview 数据传递给 NewActivity.java

【问题讨论】：

你想发送整个actorsList还是只发送一个选中的？

一个选定的列表视图内容...到另一个活动

使用Intent向其他Activity发送数据

因此，您在 Actors 类中实现 Parceable，将其作为 Extra 放入 Intent 并在目标活动中检索 Extra。这个过程的哪一部分是问题？这里的实际问题是什么？

【参考方案1】：

您可以使用Intent 将数据从一个Activity 传递到另一个。

Intent intent=new Intent(MainActivity.this,NewActivity.class); 
intent.putExtra("key",value);//
......
startActivity(intent);

在您的NewActivity 访问值中：

 variable=getIntent().getXXX("key");

【参考方案2】：

尝试使用GSON 库从您的模型生成 json（字符串）。把它放到Intent 并开始新的Activity。

【参考方案3】：

您可以使用共享的 SharedPrefences

SharedPreferences pref = getSharedPreferences("MYPrefrences", 0);

保存

Editor prefsEditor = pref.edit();

Gson gson = new Gson();

String json = gson.toJson("MyObject");

prefsEditor.putString("MyObject", json);

prefsEditor.commit();

为了得到

Gson gson = new Gson();

String json = mPrefs.getString("MyObject", "");

Actor actor = gson.fromJson(json, Actor.class);

【参考方案4】：

在您的 Actors.java 类中实现 Serializable (http://developer.android.com/reference/java/io/Serializable.html)。在您的 setOnItemClickListener 中，使用以下代码：

Intent newIntent = new Intent(thisActivity.this, NextActivity.class);
newIntent.putExtra("key", value);
startActivity(newIntent);

在您的 NextActivity.class 中，您可以像这样取回对象：

Intent intent = getIntent();
YourClass object = intent.getSerializableExtra("key");

这将为您提供整个对象及其所有属性。

【参考方案5】：

用这个替换你的代码，

    @Override
public void onItemClick(AdapterView<?> arg0, View arg1, int position,
                        long id) 

    Actors myActor = actorsList.get(position);

    // create JSON object from the above object with getter methods
    JSONObject myActorJSON = new JSONObject();
    myActorJSON.put("name", myActor.getName());
    myActorJSON.put("description", myActor.getDescription());
    myActorJSON.put("dob", myActor.getDOB());
    myActorJSON.put("country", myActor.getCountry());
    myActorJSON.put("height", myActor.getHeight());
    myActorJSON.put("spouse", myActor.getSpouse());
    myActorJSON.put("children", myActor.getChildren());
    myActorJSON.put("image", myActor.getImage());

    //you can send the Actors object or JSONObject to the new Activity
    // through intent as
    Intent i = new Intent(this, NewActivity.class);
    i.putExtra("ACTOR_OBJECT", myActor);    //Actors class should extend serializable interface
    i.putExtra("ACTOR_JSON_OBJECT", myActorJSON.toString());
    startActivity(i);

和

    //Now in NewActivity.class extract tha data from intent as
Intent i = getIntent();
Actors receivedActorObject = (Actors)i.getSerializableExtra("ACTOR_OBJECT");
String JSONString = i.getStringExtra("ACTOR_JSON_OBJECT");
try 
    JSONObject receivedActorJSON = new JSONObject(JSONString);
 catch (JSONException e) 
    e.printStackTrace();

让我知道它是否适合您... 并将其标记为答案，以便对其他人有用...

【参考方案6】：

关于你的 onClick 方法

public void onItemClick(AdapterView<?> arg0, View arg1, int position,
                long id) 
            // TODO Auto-generated method stub
            Toast.makeText(getApplicationContext(), actorsList.get(position).getName(), Toast.LENGTH_LONG).show();
            Actor selectedActor = actorsList.get(position);
            JSONObject obj = new JsonObject();
            obj.put("name",selectedActor.getName());
            //add other values of actor like that
            Intent i = new Intent(MainActirity.this,otherActivity.class);
            i.putExtra("Actor",obj.toString());
            startActivity(i);

        

在您的接收活动中

Intent i = getIntent();
JSONObject obj = new JSONObject(i.getStringExtra("Actor"));

也可以看看Intent