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:
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< 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):
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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:
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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:
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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:
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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:
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服务器之家。
原文链接:https://blog.csdn.net/qq_33022345/article/details/52864205