Android Fragment实现列表和内容联动 Android Fragment实现列表和内容联动

时间:2021-03-30 Knick_Zhang 人气:4

在平板上经常能看到这种的情况：左边是一个列表，右边是列表项对应的内容，当点击某一个列表时，右边内容区也会随之改变。下面使用Fragment简单的demo：

思路：在MainActivity定义一个回调接口，并在列表点击回调该接口，然后在内容区的Fragment设置回调，同时改变Fragment的显示内容。具体代码如下：

主布局：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:orientation="horizontal"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:layout_marginLeft="16dp"
  android:layout_marginRight="16dp"
  android:divider="?android:attr/dividerVertical"
  android:showDividers="middle">

  <ListView
    android:id="@+id/book_list"
    android:layout_width="0dp"
    android:layout_height="match_parent"
    android:layout_weight="1"/>

  <FrameLayout
    android:id="@+id/book_detail_container"
    android:layout_width="0dp"
    android:layout_height="match_parent"
    android:layout_weight="3"/>

</LinearLayout>

ListView的item布局和内容区Fragment的布局都比较简单，分别是一个Textview和两个Textview布局，这里不再贴出。

MainActivity类（内容区的数据是写死的，仅仅做演示作用，一般来说需要从网络上获取数据）：

public class MainActivity extends Activity
{
  private OnChangeListener onchangedListener;
  List<Book> books;
  List<String> book_name = new ArrayList<>();
  ListView listView;
  Adapter adapter;
  @Override
  protected void onCreate(Bundle savedInstanceState)
  {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    books = new ArrayList<>();
    initData();
    for (int i = 0 ; i < books.size() ; i++)
    {
      book_name.add(books.get(i).getName());
    }

    listView = (ListView) findViewById(R.id.book_list);
    adapter = new Adapter(book_name , this);
    listView.setAdapter(adapter);

    MyFragment fragment = new MyFragment();
    FragmentManager fragmentManager = getFragmentManager();
    FragmentTransaction transaction = fragmentManager.beginTransaction();
    transaction.replace(R.id.book_detail_container , fragment);
    transaction.commit();

    listView.setOnItemClickListener(new AdapterView.OnItemClickListener()
    {
      @Override
      public void onItemClick(AdapterView<?> parent, View view, int position, long id)
      {
        adapter.setSelectedPosition(position);
        adapter.notifyDataSetInvalidated();

        if (onchangedListener != null)
        {
          onchangedListener.changeText(books.get(position));
        }
      }
    });
  }

  private void initData()
  {
    Book book1 = new Book();
    book1.setId(1);
    book1.setName("疯狂Java讲义");
    book1.setDesc("一本全面的，深入的Java学习图书，受到广大读者的热烈喜爱，已经被多家高校选为教材，成为国内一线的Java学习素材");
    books.add(book1);

    Book book2 = new Book();
    book2.setId(2);
    book2.setName("疯狂Android讲义");
    book2.setDesc("Android学习者的首选教材，常年占据京东，当当，亚马逊3大网店Android销量排行榜首，是人人可必备的Android入门图书");
    books.add(book2);

    Book book3 = new Book();
    book3.setId(3);
    book3.setName("Java EE企业应用实战");
    book3.setDesc("全面介绍Java EE开发的Struts2 ， Spring 3 ， Hibernate 4 架构，可以通过该书系统学习企业级开发，全面掌握Java学习");
    books.add(book3);

    Book book4 = new Book();
    book4.setId(4);
    book4.setName("HTML5开发");
    book4.setDesc("全面介绍HTML5，CSS ，JavaScript等知识点，通过该书可以系统的学习Web前端开发，通常Javascript脚本设置动态页面");
    books.add(book4);
  }

  public void setOnChangeListener(OnChangeListener onChangeListener)
  {
    this.onchangedListener = onChangeListener;
  }

  interface OnChangeListener
  {
    void changeText(Book book);
  }
}

列表的Adapter类：

public class Adapter extends BaseAdapter
{
  private List<String> mData;
  private LayoutInflater layoutInflater;
  private int selectionPosition = -1;
  public Adapter(List<String> data , Context context)
  {
    this.mData = data;
    this.layoutInflater = LayoutInflater.from(context);
  }

  @Override
  public int getCount()
  {
    return mData.size();
  }

  @Override
  public Object getItem(int position)
  {
    return mData.get(position);
  }

  @Override
  public long getItemId(int position)
  {
    return position;
  }

  @Override
  public View getView(int position, View convertView, ViewGroup viewGroup)
  {
    ViewHolder viewHolder = null;
    if (convertView == null)
    {
      viewHolder = new ViewHolder();
      convertView = layoutInflater.inflate(R.layout.item_layout , null);
      viewHolder.tv = (TextView) convertView.findViewById(R.id.item_text);
      convertView.setTag(viewHolder);
    }
    else
    {
      viewHolder = (ViewHolder) convertView.getTag();
    }

    viewHolder.tv.setText(mData.get(position));
    if (selectionPosition == position)
    {
      viewHolder.tv.setBackgroundColor(Color.YELLOW);
    }
    else
    {
      viewHolder.tv.setBackgroundColor(Color.WHITE);
    }
    return convertView;
  }

  public void setSelectedPosition(int position)
  {
    this.selectionPosition = position;
  }

  class ViewHolder
  {
    TextView tv;
  }
}

内容区的Fragment类：

public class MyFragment extends Fragment
{
  MainActivity activity;
  private TextView title;
  private TextView desc;
  @Nullable
  @Override
  public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
  {
    View view = inflater.inflate(R.layout.fragment_book_detail , null);
    title = (TextView) view.findViewById(R.id.book_title);
    desc = (TextView) view.findViewById(R.id.book_desc);
    Log.d("fragment" , "Created");
    activity = (MainActivity) getActivity();
    activity.setOnChangeListener(new MainActivity.OnChangeListener()
    {
      @Override
      public void changeText(Book book)
      {
        title.setText(book.getName());
        desc.setText(book.getDesc());
      }
    });
    return view;
  }
}

Book实体类：

public class Book
{
  private int id;
  private String name;
  private String desc;
  public Book()
  {
  }

  public Book(int id , String name , String desc)
  {
    this.id = id;
    this.name = name;
    this.desc = desc;
  }

  public void setName(String name) {
    this.name = name;
  }

  public void setId(int id) {
    this.id = id;
  }

  public void setDesc(String desc) {
    this.desc = desc;
  }

  public int getId() {
    return id;
  }

  public String getName() {
    return name;
  }

  public String getDesc() {
    return desc;
  }
}

效果：

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