我正在开发一个Android应用程序，当前在MainActivity中显示文章列表并且工作正常，我想通过添加包含文章类别和“主页”的导航抽屉使应用程序更复杂一些“按钮在他们上面。
所以我在Android Studio上开始了一个新项目，我选择了导航抽屉的空白应用程序，然后我手动将我以前的应用程序导入到这个新项目中，并将我以前的MainActivity重命名为HomePage.java，因为这里的MainActivity用于导航抽屉。
我做了很多研究，我认为我必须将我的活动转换成碎片才能使用导航抽屉，但我不知道如何。
这是MainActivity.java：
import android.app.Activity;
import android.content.Intent;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.support.v4.widget.DrawerLayout;
public class MainActivity extends ActionBarActivity
implements NavigationDrawerFragment.NavigationDrawerCallbacks {
/**
* Fragment managing the behaviors, interactions and presentation of the navigation drawer.
*/
private NavigationDrawerFragment mNavigationDrawerFragment;
/**
* Used to store the last screen title. For use in {@link #restoreActionBar()}.
*/
private CharSequence mTitle;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mNavigationDrawerFragment = (NavigationDrawerFragment)
getSupportFragmentManager().findFragmentById(R.id.navigation_drawer);
mTitle = getTitle();
// Set up the drawer.
mNavigationDrawerFragment.setUp(
R.id.navigation_drawer,
(DrawerLayout) findViewById(R.id.drawer_layout));
}
@Override
public void onNavigationDrawerItemSelected(int position) {
// update the main content by replacing fragments
FragmentManager fragmentManager = getSupportFragmentManager();
fragmentManager.beginTransaction()
.replace(R.id.container, PlaceholderFragment.newInstance(position + 1))
.commit();
}
public void onSectionAttached(int number) {
switch (number) {
case 1:
mTitle = getString(R.string.title_section1); //The Home Button
break;
case 2:
mTitle = getString(R.string.title_section2);
break;
case 3:
mTitle = getString(R.string.title_section3);
break;
}
}
public void restoreActionBar() {
ActionBar actionBar = getSupportActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_STANDARD);
actionBar.setDisplayShowTitleEnabled(true);
actionBar.setTitle(mTitle);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
if (!mNavigationDrawerFragment.isDrawerOpen()) {
// Only show items in the action bar relevant to this screen
// if the drawer is not showing. Otherwise, let the drawer
// decide what to show in the action bar.
getMenuInflater().inflate(R.menu.main, menu);
restoreActionBar();
return true;
}
return super.onCreateOptionsMenu(menu);
}
@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_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
/**
* The fragment argument representing the section number for this
* fragment.
*/
private static final String ARG_SECTION_NUMBER = "section_number";
/**
* Returns a new instance of this fragment for the given section
* number.
*/
public static PlaceholderFragment newInstance(int sectionNumber) {
PlaceholderFragment fragment = new PlaceholderFragment();
Bundle args = new Bundle();
args.putInt(ARG_SECTION_NUMBER, sectionNumber);
fragment.setArguments(args);
return fragment;
}
public PlaceholderFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
return rootView;
}
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
((MainActivity) activity).onSectionAttached(
getArguments().getInt(ARG_SECTION_NUMBER));
}
}
}
这是HomePage.java：
import java.util.ArrayList;
import java.util.List;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.ListActivity;
import android.app.ProgressDialog;
import android.content.Context;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.text.Html;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TextView;
public class HomePage extends ListActivity {
//Create a progress dialog instance
private ProgressDialog pDialog;
// JSON Node names
private static final String TAG_ARTICLES = "articles";
private static final String TAG_ID = "id";
private static final String TAG_TITLE = "title";
private static final String TAG_TEASER = "teaser";
private static final String TAG_COVER_PHOTO = "cover_photo";
String call_url = "http://www.ana.fm/api/main/?start=0&count=20";
int start_get = 0;
int count_get = 20;
int lastItemIndex = 0;
ListView lv;
//Articles JSONArray
JSONArray articles = null;
//Defining the articles list with type Article
List<Article> articleList;
Button loadMoreButton;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.home_page);
articleList = new ArrayList<>();
//Getting the ListView
lv = getListView();
//add the footer before adding the adapter, else the footer will not load!
View footerView = ((LayoutInflater) this.getSystemService(Context.LAYOUT_INFLATER_SERVICE)).inflate(R.layout.list_footer, null, false);
lv.addFooterView(footerView);
//Add click listener to the load more button
loadMoreButton = (Button) findViewById(R.id.loadMoreBtn);
loadMoreButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
lastItemIndex = lv.getLastVisiblePosition();
start_get = start_get + 20;
call_url = "http://www.ana.fm/api/main/?start=".concat(String.valueOf(start_get)).concat("&count=20");
// Calling async task to get json
new GetArticles().execute();
}
});
// Listview on item click listener
lv.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
String article_id = ((TextView) view.findViewById(R.id.article_id))
.getText().toString();
// Starting single article activity
Intent in = new Intent(getApplicationContext(),
SingleArticleActivity.class);
in.putExtra(TAG_ID, article_id);
startActivity(in);
}
});
// Calling async task to get json
new GetArticles().execute();
}
/**
* Async task class to get json by making HTTP call
*/
private class GetArticles extends AsyncTask<Void, Void, Void> {
@Override
protected void onPreExecute() {
super.onPreExecute();
// Showing progress dialog
pDialog = new ProgressDialog(HomePage.this);
pDialog.setMessage("Please wait...");
pDialog.setCancelable(false);
pDialog.show();
}
@Override
protected Void doInBackground(Void... arg0) {
// Creating service handler class instance
ServiceHandler sh = new ServiceHandler();
// Making a request to url and getting response
//call_url is defined previously
String jsonStr = sh.makeServiceCall(call_url, ServiceHandler.GET);
if (jsonStr != null) {
try {
JSONObject jsonObj = new JSONObject(jsonStr);
// Getting JSON Array node
articles = jsonObj.getJSONArray(TAG_ARTICLES);
// looping through All Articles
for (int i = 0; i < articles.length(); i++) {
JSONObject c = articles.getJSONObject(i);
String id = c.getString(TAG_ID);
String title = c.getString(TAG_TITLE);
title = Html.fromHtml(title).toString();
String teaser = c.getString(TAG_TEASER);
teaser = Html.fromHtml(teaser).toString();
String cover_photo = "http://www.ana.fm/med_photos/articles/";
cover_photo = cover_photo.concat(c.getString(TAG_COVER_PHOTO));
//Getting an object from the Article class
Article article = new Article();
//Setting the values to the object's variables
article.setId(id);
article.setTitle(title);
article.setTeaser(teaser);
article.setImageUrl(cover_photo);
// adding article to the article list
articleList.add(article);
}
} catch (JSONException e) {
e.printStackTrace();
}
} else {
Log.e("ServiceHandler", "Couldn't get any data from the url");
//new GetContacts().execute();
}
return null;
}
@Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
// Dismiss the progress dialog
if (pDialog.isShowing())
pDialog.dismiss();
/**
* Calling my custom adapter to view the images as well
* */
MyAdapter adapter = new MyAdapter(getApplicationContext(), R.layout.list_item, articleList);
setListAdapter(adapter);
lv.setSelection(lastItemIndex);
}
}
}
现在我想要的是在点击导航抽屉（侧面菜单）上的“主页”按钮后导航到HomePage.java。
任何人都可以提供帮助吗？