今日头条 新闻频道展示

思路：用HorizontalScrollView 来对频道进行展示，用ViewPager + FragmentPagerAdapter + Fragment 方式来展示每个栏目下的新闻列表

一：对频道的添加展示

二：viewPager 新闻列表的展示

一：对频道的添加展示

创建了一个新闻类NewsClassify,进行新闻栏目的存储，之后根据栏目的多少动态创建TextView，并且设置其

setBackgroundResource（）、setTextAppearance（）、setTextColor（）等属性，并添加监听

public class MainActivity extends ActionBarActivity {

private HorizontalScrollView mHorizontalScrollView;
private LinearLayout mRadioGroup_content;
private LinearLayout ll_more_columns;
private ViewPager mViewPager;

/** 屏幕宽度 */
private int mScreenWidth = 0;
/** Item宽度 */
private int mItemWidth = 0;
/*
* 临时数据
*/
private List<NewsClassify> data = new ArrayList<NewsClassify>();

private List<NewsFragment> fragments = new ArrayList<NewsFragment>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);

initView();
initFragment();

}
/*
* 初始化
*/
private void initView(){
mScreenWidth = BaseTools.getWindowsWidth(this);
mItemWidth = mScreenWidth / 7;// 一个Item宽度为屏幕的1/7

mHorizontalScrollView = (HorizontalScrollView) findViewById(R.id.mHorizontalScrollView);
mRadioGroup_content = (LinearLayout) findViewById(R.id.mRadioGroup_content);
ll_more_columns = (LinearLayout) findViewById(R.id.ll_more_columns);
mViewPager = (ViewPager) findViewById(R.id.mViewPager);

addData();//添加数据

int size = data.size();
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(mItemWidth, LayoutParams.WRAP_CONTENT);
params.leftMargin = 5;
params.rightMargin = 5;
/*
* 四个字以上字显示不全的问题
*/
for(int i = 0;i < size;i ++){
final TextView textView = new TextView(this);
textView.setBackgroundResource(R.drawable.title_selected);
//通过ColorStateList得到xml中的配置的颜色的。好多需要xml中配置的都要类似这样的映射xml文件
textView.setTextColor(getResources().getColorStateList(R.drawable.title_color_selected));
textView.setSingleLine(true);
textView.setTextAppearance(this, R.style.TextStyle);
textView.setGravity(Gravity.CENTER);
textView.setPadding(5, 5, 5, 5);
textView.setText(data.get(i).getTitle());
textView.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
int size = data.size();
for(int i = 0;i < size;i ++){
View temp = mRadioGroup_content.getChildAt(i);
if(temp != v){
temp.setSelected(false);
}else{
temp.setSelected(true);
mViewPager.setCurrentItem(i);
}
}
}
});
mRadioGroup_content.addView(textView, params);
}
}

private void selected(int position){
//		for (int i = 0; i < 2; i++) {
View checkView = mRadioGroup_content.getChildAt(position);
int k = checkView.getMeasuredWidth();
int l = checkView.getLeft();
int i2 = l - k / 2 ;

mHorizontalScrollView.scrollTo(i2, 0);
//		}

boolean bool = false;
int size = data.size();
for(int i = 0;i < size;i ++){
View view = mRadioGroup_content.getChildAt(i);
if(i == position){
bool = true;
}else{
bool = false;
}
view.setSelected(bool);
}
}
/*
* 初始化Fragment
*/
private void initFragment(){
int size = data.size();
for(int i = 0;i < size;i ++){
Bundle bundle = new Bundle();
bundle.putString("text", data.get(i).getTitle());
NewsFragment fragment = new NewsFragment();
fragment.setArguments(bundle);
fragments.add(fragment);
}

NewsFragmentPagerAdapter adapter = new NewsFragmentPagerAdapter(getSupportFragmentManager(), fragments);

mViewPager.setAdapter(adapter);

mViewPager.setOnPageChangeListener(new OnPageChangeListener() {

@Override
public void onPageSelected(int arg0) {
// TODO Auto-generated method stub
mViewPager.setCurrentItem(arg0);
selected(arg0);
}

@Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
// TODO Auto-generated method stub
}

@Override
public void onPageScrollStateChanged(int arg0) {
// TODO Auto-generated method stub

}
});

}

private void addData(){
NewsClassify news = new NewsClassify();
news.setId(0);
news.setTitle("头条");
data.add(news);

news = new NewsClassify();
news.setId(1);
news.setTitle("手机");
data.add(news);

news = new NewsClassify();
news.setId(2);
news.setTitle("科技");
data.add(news);

news = new NewsClassify();
news.setId(3);
news.setTitle("数码");
data.add(news);

news = new NewsClassify();
news.setId(4);
news.setTitle("互联网");
data.add(news);

news = new NewsClassify();
news.setId(5);
news.setTitle("娱乐");
data.add(news);

news = new NewsClassify();
news.setId(6);
news.setTitle("智能手机");
data.add(news);

news = new NewsClassify();
news.setId(7);
news.setTitle("财经");
data.add(news);

news = new NewsClassify();
news.setId(8);
news.setTitle("体育");
data.add(news);

news = new NewsClassify();
news.setId(9);
news.setTitle("汽车");
data.add(news);

news = new NewsClassify();
news.setId(10);
news.setTitle("段子");
data.add(news);

news = new NewsClassify();
news.setId(11);
news.setTitle("上海");
data.add(news);

news = new NewsClassify();
news.setId(12);
news.setTitle("图片");
data.add(news);

news = new NewsClassify();
news.setId(13);
news.setTitle("房产");
data.add(news);

news = new NewsClassify();
news.setId(14);
news.setTitle("电台");
data.add(news);

news = new NewsClassify();
news.setId(15);
news.setTitle("原创");
data.add(news);
}

}

二：viewPager 新闻列表的展示

viewpager 适配器为FragmentPagerAdapter，并且用Fragment进行新闻列表展示，当然也可以用

PagerAdapter 这时就不需要Fragment

谷歌官方认为，ViewPager应该和Fragment一起使用时，此时ViewPager的适配器是FragmentPagerAdapter，

当你实现一个FragmentPagerAdapter,你必须至少覆盖以下方法:

getCount()

getItem()

如果ViewPager没有和Fragment一起，ViewPager的适配器是PagerAdapter，它是基类提供适配器来填充页面ViewPager内部，

当你实现一个PagerAdapter,你必须至少覆盖以下方法:

instantiateItem(ViewGroup, int)

destroyItem(ViewGroup, int, Object)

getCount()

isViewFromObject(View, Object)

class NewsFragmentPagerAdapter:：

public class NewsFragmentPagerAdapter extends FragmentPagerAdapter {

private List<NewsFragment> list = null;
public NewsFragmentPagerAdapter(FragmentManager fm, List<NewsFragment> list) {
super(fm);
// TODO Auto-generated constructor stub
this.list = list;
}

@Override
public Fragment getItem(int arg0) {
// TODO Auto-generated method stub
return list.get(arg0);
}

@Override
public int getCount() {
// TODO Auto-generated method stub
return list.size();
}

}

class NewsFragment:：

public class NewsFragment extends Fragment {

private String text = "";
@Override
public void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
Bundle bundle = getArguments();
text = bundle != null ? bundle.getString("text") : "";
}
//新闻列表的展示就是用这个
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// TODO Auto-generated method stub

View view = LayoutInflater.from(getActivity()).inflate(R.layout.fragment_item, null);
TextView textView = (TextView) view.findViewById(R.id.textView);
textView.setText(text);

return view;
}

}