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Android Fragment实现列表和内容联动

程序员文章站 2022-03-23 13:49:31
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mai...

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:

Android Fragment实现列表和内容联动

以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持。