Tengo una aplicación que contiene una vista de lista. Cada elemento de la vista de lista contiene grandes párrafos de texto. Por lo tanto, quiero colocar el texto en un archivo .txt, guardarlo en parse.ccom y usar los archivos de texto para recibir texto en mi vista de texto de los elementos de la vista de lista. Pero cuando presiono el elemento de vista de lista no se muestra texto del archivo de texto. Solo se muestra la página en blanco.

Por favor, ayúdame Aquí está mi código

actividad principal.java

package com.mycompany.myapp;

import android.app.*;
import android.os.*;
import com.parse.*;
import android.widget.*;
import java.util.*;
import android.util.*;

public class MainActivity extends Activity 
{
ListView listview;
List<ParseObject> ob;
ProgressDialog mProgressDialog;
ListViewAdapter adapter;
private List<Textfile> textfilelist = null;

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

    // Add your initialization code here
    Parse.initialize(this, "Hwq4ExtHsfHimcHFO3596nYv4dcwd6MX2hdIC7wN", "x7iF0nUMRS1T1boXBOAHhwNI8HUkhGuGapJFksI6");

    ParseUser.enableAutomaticUser();
    ParseACL defaultACL = new ParseACL();

    // If you would like all objects to be private by default, remove this line.
    defaultACL.setPublicReadAccess(true);

    ParseACL.setDefaultACL(defaultACL, true);

    new RemoteDataTask().execute();
}

private class RemoteDataTask extends AsyncTask<Void, Void, Void> {
    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        // Create a progressdialog
        mProgressDialog = new ProgressDialog(MainActivity.this);
        // Set progressdialog title
        mProgressDialog.setTitle("loading");
        // Set progressdialog message
        mProgressDialog.setMessage("Loading...");
        mProgressDialog.setIndeterminate(false);
        // Show progressdialog
        mProgressDialog.show();
    }

    @Override
    protected Void doInBackground(Void... params) {
        // Create the array
        textfilelist = new ArrayList<Textfile>();
        try {
            // Locate the class table named "TestText" in Parse.com
            ParseQuery<ParseObject> query = new ParseQuery<ParseObject>(
                "TestText");

            query.orderByDescending("_created_at");
            ob= query.find();

            for (ParseObject txtobject : ob) {
                // Locate images in flag column
                ParseFile image = (ParseFile) txtobject.get("image");

                Textfile map = new Textfile();
                map.setText((String) txtobject.get("text"));
                map.setTxtview((String) txtobject.get("textfile"));
                map.setImage(image.getUrl());
                textfilelist.add(map);
            }
        } catch (ParseException e) {
            Log.e("Error", e.getMessage());
            e.printStackTrace();
        }
        return null;
    }

    @Override
    protected void onPostExecute(Void result) {
        // Locate the listview in listview_main.xml
        listview = (ListView) findViewById(R.id.listview);
        // Pass the results into ListViewAdapter.java
        adapter = new ListViewAdapter(MainActivity.this,
                                      textfilelist);
        // Binds the Adapter to the ListView
        listview.setAdapter(adapter);
        // Close the progressdialog
        mProgressDialog.dismiss();
        }
        }



}

archivo de texto.java

package com.mycompany.myapp;

public class Textfile

{

private String text;
private String image;
private String txtview;

public void setTxtview(String txtview)
{
    this.txtview = txtview;
}

public String getTxtview()
{
    return txtview;
}

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

public String getImage()
{
    return image;
}



public void setText(String text)
{
    this.text = text;
}

public String getText()
{
    return text;
}}

listview adapter.java

package com.mycompany.myapp;
import android.widget.*;
import android.view.*;
import android.content.*;
import java.util.*;
import android.view.View.*;

public class ListViewAdapter extends BaseAdapter
{

// Declare Variables
Context context;
LayoutInflater inflater;
ImageLoader imageLoader;
private List<Textfile> textfilelist = null;
private ArrayList<Textfile> arraylist;

public ListViewAdapter(Context context,
                       List<Textfile> textfilelist) {
    this.context = context;
    this.textfilelist = textfilelist;
    inflater = LayoutInflater.from(context);
    this.arraylist = new ArrayList<Textfile>();
    this.arraylist.addAll(textfilelist);
    imageLoader = new ImageLoader(context);

    }

public class ViewHolder {
    TextView heading;
    ImageView mainimage;
}

@Override
public int getCount()
{
    // TODO: Implement this method
    return textfilelist.size();
}

@Override
public Object getItem(int position)
{
    // TODO: Implement this method
    return textfilelist.get(position);
}

@Override
public long getItemId(int position)
{
    // TODO: Implement this method
    return position;
}

@Override
public View getView(final int position, View view, ViewGroup parent)
{
    final ViewHolder holder;
    if (view == null) {
        holder = new ViewHolder();
    view = inflater.inflate(R.layout.listview_item, null);
    holder.heading = (TextView) view.findViewById(R.id.listview_itemTextView);
    holder.mainimage = (ImageView) view.findViewById(R.id.listview_itemImageView);
    view.setTag(holder);
    }
    else{
        holder = (ViewHolder) view.getTag();
        }

        holder.heading.setText(textfilelist.get(position).getText());

    imageLoader.DisplayImage(textfilelist.get(position).getImage(),
                             holder.mainimage);


    view.setOnClickListener(new OnClickListener(){

            @Override
            public void onClick(View arg0) {
                Intent intent = new Intent(context, SingleItemView.class);
                intent.putExtra("text",
                                (textfilelist.get(position).getText()));
                // Pass all data flag
                intent.putExtra("image",
                                (textfilelist.get(position).getImage()));
                // Start SingleItemView Class

                context.startActivity(intent);
                }
                });



    // TODO: Implement this method
    return view;
 }

}

singleitemview.java

package com.mycompany.myapp;
import android.app.*;
import android.os.*;
import android.content.*;
import android.widget.*;

public class SingleItemView extends Activity
{
String text;

@Override
protected void onCreate(Bundle savedInstanceState)
{
    // TODO: Implement this method
    super.onCreate(savedInstanceState);
    setContentView(R.layout.singleitemview);

    Intent i = getIntent();

    text= i.getStringExtra("textfile");

    TextView txt= (TextView) findViewById(R.id.singleitemviewTextView);

    txt.setText(text);
}

}