一个基于RSS的新闻应用

【实例截图】

【核心代码】

package com.example.lhhxkj.news_application;
import android.content.DialogInterface;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import java.lang.String;

public class MainActivity extends AppCompatActivity {
    ArrayAdapter<String> adapterMainSubjects;
    ListView myMainListView;

    // NEWS categories 
    String[][] myUrlCaptionMenu = {
            {"http://www.npr.org/rss/rss.php?id=1001", "Arts & Entertainment"},
            {"http://www.npr.org/rss/rss.php?id=1003", "Business"},
            {"http://www.npr.org/rss/rss.php?id=1004", "World News"},
            {"http://www.npr.org/rss/rss.php?id=1006", "U.S. News"},
            {"http://www.npr.org/rss/rss.php?id=1008", "People & Places"},
            {"http://www.npr.org/rss/rss.php?id=1012", "Politics & Society"},
            {"http://www.npr.org/rss/rss.php?id=1021", "Top Stories"},
            {"http://www.npr.org/rss/rss.php?id=1057", "Opinion"}
    };
    //define convenient URL and CAPTIONs arrays
    String[] myUrlCaption = new String[myUrlCaptionMenu.length];
    String[] myUrlAddress = new String[myUrlCaptionMenu.length];
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        toolbar.setLogo(R.mipmap.ic_launcher);//为Toolbar设置Logo
        setSupportActionBar(toolbar);
        for (int i = 0; i < myUrlCaptionMenu.length; i ) {
            myUrlAddress[i] = myUrlCaptionMenu[i][0];
            myUrlCaption[i] = myUrlCaptionMenu[i][1];
        }

        // clicking on a row shows dialogBox with more info about selected item
        myMainListView = (ListView) this.findViewById(R.id.myListView);
        myMainListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            public void onItemClick(AdapterView<?> _av, View _v,
                                    int _index, long _id) {
                String urlAddress = myUrlAddress[_index];
                String urlCaption = myUrlCaption[_index];
                int count = 0;
                count ;
                //create an Intent to talk to activity: ShowHeadlines
                Intent callShowHeadLines = new Intent(MainActivity.this,
                        ShowHeadLines.class);
                //prepare a Bundle and add the input arguments: url & caption
                Bundle myData = new Bundle();
                myData.putString("urlAddress", urlAddress);
                myData.putString("urlCaption", urlCaption);
                callShowHeadLines.putExtras(myData);
                startActivity(callShowHeadLines);
            }//end onItemClick
        });//end setOnItemClickListener

        // fill up the Main‐GUI’s ListView with main news categories
        adapterMainSubjects = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, myUrlCaption);//simple_list_item_1:android default
        myMainListView.setAdapter(adapterMainSubjects);
    }//onCreate

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }
    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        //noinspection SimplifiableIfStatement
        if (id == R.id.action_history) {
            return true;
        }
        else if (id == R.id.action_goBack) {
            Intent intent = new Intent(MainActivity.this, MainActivity.class);
            startActivity(intent);
        }
        else if (id == R.id.action_about) {
            AlertDialog.Builder dialog = new AlertDialog.Builder(MainActivity.this);
            dialog.setTitle("About the News_application");
            dialog.setIcon(R.mipmap.ic_launcher);
            dialog.setMessage("This is a simple News Application. You can read news and learn more details\n"
                    "about the news you are interested in.");
            dialog.setPositiveButton("OK", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                }
            });
            dialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                }
            });
            dialog.show();
        }//end if

       else if (id == R.id.action_exit) {
            android.os.Process.killProcess(android.os.Process.myPid());
        }
        return super.onOptionsItemSelected(item);
    }
}

(6)ShowHeadLines.java

package com.example.lhhxkj.news_application;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.text.Html;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import java.lang.String;
import java.util.ArrayList;
/**
 * Created by lhhxkj on 2016/5/22.
 */
public class ShowHeadLines extends AppCompatActivity {
    
    ArrayList<SingleItem> newsList =new ArrayList<SingleItem>();
    ListView myListView;
    String urlAddress ="";
    String urlCaption ="";
    SingleItem selectedNewsItem;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.storylist);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar2);
        toolbar.setTitle("Story Title");   //set the title
        //toolbar.setLogo(R.drawable.ic_stat_name);  //add the icon
        setSupportActionBar(toolbar);

        //set up an actionbar
        //ActionBar actionBar = getActionBar();
        myListView = (ListView) this.findViewById(R.id.myListView);
        // find out which intent is calling us
        Intent callingIntent = getIntent();
        // grab data bundle holding selected url & caption sent to us
        Bundle myBundle = callingIntent.getExtras();
        urlAddress = myBundle.getString("urlAddress");
        urlCaption = myBundle.getString("urlCaption");
        // update app's top 'TitleBar' (eg. 'NPR ‐ Business Wed April 09, 2014')       
        //this.setTitle("NPR ‐ " urlCaption " \t" );

        // clicking on a row shows dialogBox with more info about selected item
        myListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            public void onItemClick(AdapterView<?> av, View v, int index, long id) {
                selectedNewsItem = newsList.get(index);
                showNiceDialogBox(selectedNewsItem, getApplicationContext());
            }
        });
        // get stories for the selected news option
        DownloadRssFeed downloader = new DownloadRssFeed(ShowHeadLines.this);
        downloader.execute(urlAddress, urlCaption);
        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent intent=new Intent(ShowHeadLines.this,MainActivity.class);
                startActivity(intent);
            }
        });
    }//onCreate

    public void showNiceDialogBox(SingleItem selectedStoryItem,
                                  Context context){
        // make a nice looking dialog box (story summary, btnClose, btnMore)
        // CAUTION: (check)on occasions title and description are the same!
        String title = selectedStoryItem.getTitle();
        String description = selectedStoryItem.getDescription();
        if (title.toLowerCase().equals(description.toLowerCase())){
            description = "";
        }
        try {
                //CAUTION: sometimes TITLE and DESCRIPTION include HTML markers
                final Uri storyLink = Uri.parse(selectedStoryItem.getLink());
                AlertDialog.Builder myBuilder = new AlertDialog.Builder(this);
                myBuilder
                        .setTitle(Html.fromHtml(urlCaption))
                        .setMessage(title "\n\n" Html.fromHtml(description) "\n")
                .setPositiveButton("Close", null)
                .setNegativeButton("More",new DialogInterface.OnClickListener(){
                    public void onClick(DialogInterface dialog,int whichOne){
                        Intent browser = new Intent(Intent.ACTION_VIEW,storyLink);
                        startActivity(browser);
                    }
                })//setNegativeButton
                .show();
            }catch (Exception e) {
                Log.e("Error DialogBox", e.getMessage());
            }
        }//showNiceDialogBox


    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.storylist_menu, menu);
        return true;
    }

        @Override
        public boolean onOptionsItemSelected(MenuItem item) {
            // Handle action bar item clicks here. The action bar will
            // automatically handle clicks on the Home/Up button, so long
            // as you specify a parent activity in AndroidManifest.xml.
            int id = item.getItemId();
            //noinspection SimplifiableIfStatement
            if (id == R.id.action_history) {
                return true;
            }
            if (id == R.id.action_about) {
                AlertDialog.Builder dialog= new AlertDialog.Builder(ShowHeadLines.this);
                dialog.setTitle("About the News_application");
                dialog.setIcon(R.mipmap.ic_launcher);
                dialog.setMessage("This is a simple News Application. You can read news and learn more details\n"
                        "about the news you are interested in.");
                dialog.setPositiveButton("OK", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                    }
                });
                dialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                    }
                });
                dialog.show();
            }
            return super.onOptionsItemSelected(item);
        }
}//ShowHeadLines