1.Fragment简单用法
建left和right的xml文件：
建立left和right的类：
public class Left extends Fragment {
@Override
public View onCreateView(LayoutInflater inf, ViewGroup container, Bundle savedInstanceState) {
View view = inf.inflate(R.layout.left,container,false);
return view;
}
}
public class Right1 extends Fragment {
@Override
public View onCreateView(LayoutInflater inf, ViewGroup container, Bundle savedInstanceState) {
View view = inf.inflate(R.layout.right1,container,false);
return view;
}
}
修改activity_main.xml：
动态添加Fragment：
建Right1.xml：
建Right1类：
public class Right1 extends Fragment {
@Override
public View onCreateView(LayoutInflater inf, ViewGroup container, Bundle savedInstanceState) {
View view = inf.inflate(R.layout.right1,container,false);
return view;
}
}
修改activity_main.xml：
修改MainActivity:
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button button = (Button) findViewById(R.id.button);
replaceFragment(new Right());
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
replaceFragment(new Right1());
}
});
}
private void replaceFragment(Fragment fra) {
FragmentManager fraMan = getSupportFragmentManager();
FragmentTransaction tra = fraMan.beginTransaction();
tra.replace(R.id.right_layout,fra);
tra.commit();
}
}
完成。
模拟返回栈：
tra.addToBackStack(null);
活动调用碎片中方法：
Right rigFra = (Right) getFragmentManager().findFragmentById(R.id.right);
碎片调用活动中方法：
在碎片中：
MainActivity act = (MainActivity) getActivity();
同时也可以使用这个方法获取Context。
fragment生命周期：onAttach(),onCreate(),onCreateView(),onActivityCreate(),onStart(),onResume(),onPause(),onStop(),onDestroyView(),onDestroy(),onDetach()
根据设备屏幕大小方向动态选择加载哪个布局：
修改activity_main.xml文件：
在res目录下新建layout_large文件夹,新建名为：activity_main.xml的布局：
最小宽度限定符：
新建layout-sw600dp文件夹。
综合应用——新闻应用：
1。build.gradle 中添加recyclerview支持
2.新建新闻类：News
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;
}
}
3.新建内容布局文件news_content_frag.xml
4.新建内容布局类NewsContentFragment，继承Fragment:
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);
}
}
5.对小屏模式支持，新建Activity:NewsContentAcitivty和相应布局文件news_content.xml:
public class NewsContentActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.news_content);
String newsTitle = getIntent().getStringExtra("news_title");
String newsContent = getIntent().getStringExtra("news_content");
NewsContentFragment newsContentFragment = (NewsContentFragment) getSupportFragmentManager().findFragmentById(R.id.news_content_fragment);
newsContentFragment.refresh(newsTitle,newsContent);
}
public static void actionStart(Context context,String newsTitle,String newsContent) {
Intent intent = new Intent(context,NewsContentActivity.class);
intent.putExtra("news_title",newsTitle);
intent.putExtra("new_content",newsContent);
context.startActivity(intent);
}
}
6.新建用于显示新闻列表的布局，news_title_frag.xml:
?xml version="1.0" encoding="utf-8"?>
7.新建news_item.xml作为recyclerview的子布局：
8.新建NewsTitleFragment作为展示新闻列表的碎片：
public class NewsTitleFragment extends Fragment {
private boolean isTwoPane;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.news_title_frag,container,false);
RecyclerView newsTitleRecyclerView = (RecyclerView) view.findViewById(R.id.news_title_recycler_view);
LinearLayoutManager layoutManager = new LinearLayoutManager(getActivity());
newsTitleRecyclerView.setLayoutManager(layoutManager);
NewsAdapter adapter = new NewsAdapter(getNews());
newsTitleRecyclerView.setAdapter(adapter);
return view;
}
private List getNews(){
List newsList = new ArrayList<>();
for(int i=1;i<=50;i++) {
News news = new News();
news.setTitle("This is news title" + i);
news.setContent("content" + i);
newsList.add(news);
}
return newsList;
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
if (getActivity().findViewById(R.id.news_content_layout) != null) {
isTwoPane = true;
} else {
isTwoPane = false;
}
}
class NewsAdapter extends RecyclerView.Adapter {
private List mNewsList;
class ViewHolder extends RecyclerView.ViewHolder {
TextView newsTitleText;
public ViewHolder(View view) {
super(view);
newsTitleText = (TextView)view.findViewById(R.id.news_title);
}
}
public NewsAdapter(List newsList) {
mNewsList = newsList;
}
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent,int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.news_item,parent,false);
final ViewHolder holder = new ViewHolder(view);
view.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
News news = mNewsList.get(holder.getAdapterPosition());
if (isTwoPane) {
NewsContentFragment newsContentFragment = (NewsContentFragment)getFragmentManager().findFragmentById(R.id.news_content_fragment);
newsContentFragment.refresh(news.getTitle(),news.getContent());
news.getContent();
} else {
NewsContentActivity.actionStart(getActivity(),news.getTitle(),news.getContent());
}
}
});
return holder;
}
@Override
public void onBindViewHolder(ViewHolder holder,int position) {
News news = mNewsList.get(position);
holder.newsTitleText.setText(news.getTitle());
}
@Override
public int getItemCount() {
return mNewsList.size();
}
}
}
9.修改activity_main.xml：
10.新建layout-sw600dp支持大屏，在此文件夹下新建activity_main：
2.ViewPager
简单用法，修改activity_main.xml，新建三个滑动页面：page0,page1,page2：
新建MyViewpager类和修改MainActivity：
public class MyViewpagerAdapter extends PagerAdapter {
private List pageList;
public MyViewpagerAdapter(List pageList) {
this.pageList = pageList;
}
@Override
public int getCount() {
return pageList.size();
}
@Override
public boolean isViewFromObject(View view,Object object) {
return view == object;
}
@Override
public Object instantiateItem(ViewGroup container,int position) {
container.addView(pageList.get(position));
return pageList.get(position);
}
@Override
public void destroyItem(ViewGroup container,int position,Object object) {
container.removeView(pageList.get(position));
}
}
public class MainActivity extends AppCompatActivity {
private View page0,page1,page2;
private List pageList;
private ViewPager mViewPager;
private MyViewpagerAdapter mMyViewpagerAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
LayoutInflater inflater = getLayoutInflater();
page0 = inflater.inflate(R.layout.page0,null);
page1 = inflater.inflate(R.layout.page1,null);
page2 = inflater.inflate(R.layout.page2,null);
pageList = new ArrayList<>();
pageList.add(page0);
pageList.add(page1);
pageList.add(page2);
mViewPager = (ViewPager) findViewById(R.id.viewpager);
mMyViewpagerAdapter = new MyViewpagerAdapter(pageList);
mViewPager.setAdapter(mMyViewpagerAdapter);
}
}