这是第一行代码里面的一个项目,运行后崩溃:
MainActivity.java
package com.example.newsapp;
import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.Window;
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.activity_main);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.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();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
News.java
package com.example.newsapp;
public class News {
private String title;
private String content;
public String getTitle()
{
return title;
}
public void setTitle(String title)
{
this.title=title;
}
public String getContent()
{
return content;
}
public void setContent(String content)
{
this.content=content;
}
}
NewsAdapter.java
package com.example.newsapp;
import java.util.List;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.TextView;
public class NewsAdapter extends ArrayAdapter<News>
{
private int resourceId;
public NewsAdapter(Context context,int textViewResourceId,List<News> objects)
{
super(context,textViewResourceId,objects);
resourceId=textViewResourceId;
}
@Override
public View getView(int position,View convertView,ViewGroup parent)
{
News news=getItem(position);
View view;
if (convertView==null)
{
view=LayoutInflater.from(getContext()).inflate(resourceId,null);
}
else
{
view=convertView;
}
TextView newsTitleText=(TextView)view.findViewById(R.id.news_title);
newsTitleText.setText(news.getTitle());
return view;
}
}
NewsContentActivity.java
package com.example.newsapp;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.view.Window;
public class NewsContentActivity extends FragmentActivity
{
public static void actionStart(Context context,String newsTitle,String newsContent)
{
Intent intent=new Intent(context,NewsContentActivity.class );
intent.putExtra("news_title",newsTitle);
intent.putExtra("news_content",newsContent);
context.startActivity(intent);
}
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.news_content);
FragmentManager fragmentManager=getSupportFragmentManager();
String newsTitle=getIntent().getStringExtra("news_title");
String newsContent=getIntent().getStringExtra("news_content");
NewsContentFragment newsContentFragment=(NewsContentFragment)fragmentManager.findFragmentById(R.id.news_content_fragment);
newsContentFragment.refresh(newsTitle,newsContent);
}
}
NewsContentFragment.java
package com.example.newsapp;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
public class NewsContentFragment extends Fragment
{
private View view;
@Override
public View onCreateView(LayoutInflater inflater,ViewGroup container,Bundle savedInstanceState)
{
view=inflater.inflate(R.layout.news_content_frag,container,false );
return view;
}
public void refresh(String newsTitle,String newsContent)
{
View visibilityLayout=view.findViewById(R.id.visibility_layout);
visibilityLayout.setVisibility(View.VISIBLE);
TextView newsTitleText=(TextView)view.findViewById(R.id.news_title);
TextView newsContentText=(TextView)view.findViewById(R.id.news_content);
newsTitleText.setText(newsTitle);
newsContentText.setText(newsContent);
}
}
NewsTitleFragment.java
package com.example.newsapp;
import java.util.ArrayList;
import java.util.List;
import android.app.Activity;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListView;
public class NewsTitleFragment extends Fragment implements OnItemClickListener
{
private ListView newsTitleListView;
private List<News> newsList;
private NewsAdapter adapter;
private boolean isTwoPane;
@Override
public void onAttach(Activity activity)
{
super.onAttach(activity);
newsList=getNews();
adapter=new NewsAdapter(activity,R.layout.news_item,newsList);
}
@Override
public View onCreateView(LayoutInflater inflater,ViewGroup container,Bundle savedInstanceState)
{
View view=inflater.inflate(R.layout.news_title_frag,container,false );
newsTitleListView=(ListView)view.findViewById(R.id.news_title_list_view);
newsTitleListView.setAdapter(adapter);
newsTitleListView.setOnItemClickListener(this );
return view;
}
@Override
public void onActivityCreated(Bundle savedInstanceState)
{
super.onActivityCreated(savedInstanceState);
if (getActivity().findViewById(R.id.news_content_layout)!=null )
isTwoPane=true;
else
isTwoPane=false;
}
@Override
public void onItemClick(AdapterView<?> parent,View view,int position,long id)
{
News news=newsList.get(position);
if (isTwoPane)
{
NewsContentFragment newsContentFragment=(NewsContentFragment)getFragmentManager().findFragmentById(R.id.news_content_fragment);
newsContentFragment.refresh(news.getTitle(),news.getContent());
}
else
{
NewsContentActivity.actionStart(getActivity(),news.getTitle(),news.getContent());
}
}
private List<News> getNews()
{
List<News> newsList=new ArrayList<News>();
News news1=new News();
news1.setTitle("标题");
news1.setContent("内容");
newsList.add(news1);
News news2=new News();
news2.setTitle("日记");
news2.setContent("去旅游");
newsList.add(news2);
return newsList;
}
}