android系统联系人分组特效实现(1)---分组导航和挤压动画

1.打开activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:tools="http://schemas.android.com/tools"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    tools:context=".MainActivity" >

    <ListView 

        android:id="@+id/lv"

        android:layout_width="fill_parent"

        android:layout_height="wrap_content"

        android:layout_alignParentTop="true"

        ></ListView>

    <LinearLayout 

        android:layout_width="fill_parent"

        android:layout_height="18dp"

        android:id="@+id/title_layout"

        android:background="#303030"

        android:orientation="vertical"

        >

        <TextView 

            android:layout_width="wrap_content"

            android:layout_height="wrap_content"

            android:id="@+id/title"

            android:textColor="#ffffff"

            />

    </LinearLayout>

</RelativeLayout>

布局文件很简单,一个用来展示联系人信息的ListView,还有一个LinearLayout,里面有一个TextView,它的作用是在头部始终显示一个当前分组.

2.新建item.xml布局,用于展示ListView的子项布局

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:orientation="vertical" >

    

    <LinearLayout 

        android:layout_width="fill_parent"

        android:layout_height="18dp"

        android:orientation="vertical"

        android:background="#303030"

        android:id="@+id/sort_key_layout"

        >

        <TextView 

            android:id="@+id/sort_key"

            android:layout_width="wrap_content"

            android:layout_height="wrap_content"

            android:gravity="center_horizontal"

            android:textColor="#ffffff"

            android:textSize="13sp"

            />

    </LinearLayout>

    

    <LinearLayout 

        android:layout_width="fill_parent"

        android:layout_height="50dp"

        android:orientation="horizontal"

        android:id="@+id/name_layout"

        >

        <ImageView 

            android:layout_width="wrap_content"

            android:layout_height="wrap_content"

            android:layout_gravity="center_vertical"

            android:src="@drawable/icon"

            />

        <TextView 

            android:layout_width="wrap_content"

            android:layout_height="wrap_content"

            android:id="@+id/name"

            />

    </LinearLayout>

</LinearLayout>

在这个布局文件中，首先是放入了一个和前面完成一样的分组布局，因为不仅界面头部需要展示分组，在每个分组内的第一个无素之前都需要展示分组布局。然后是加入一个简单的LinearLayout，里面包含了一个ImageView用于显示联系人头像，还包含一个TextView用于显示联系人姓名。

3.新建一个Contact.java,作为实体类

public class Contact {

    private String name;//联系人姓名

    private String SortKey;  //排序字母

    public String getName() {

        return name;

    }

    public void setName(String name) {

        this.name = name;

    }

    public String getSortKey() {

        return SortKey;

    }

    public void setSortKey(String sortKey) {

        SortKey = sortKey;

    }

}

4.接下来就是联系人列表适配器

public class ContactAdapter extends ArrayAdapter<Contact> {

    //需要渲染的Item布局

    private int resource;

    

    //字母表分组工具

    private SectionIndexer mIndexer;

    

    

    public ContactAdapter(Context context, int textViewResourceId, List<Contact> objects) {

        super(context, textViewResourceId, objects);

        resource = textViewResourceId;

    }

    

    @Override

    public View getView(int position, View convertView, ViewGroup parent) {

        

        Contact contact=getItem(position);

        LinearLayout layout=null;

        if(convertView==null){

            layout=(LinearLayout) LayoutInflater.from(getContext()).inflate(resource,null);

        }

        else{

            layout=(LinearLayout) convertView;

        }

        TextView name=(TextView) layout.findViewById(R.id.name);

        LinearLayout linearKeyLayout=(LinearLayout) layout.findViewById(R.id.sort_key_layout);

        TextView sortKey=(TextView) layout.findViewById(R.id.sort_key);

        name.setText(contact.getName());

        int section=mIndexer.getSectionForPosition(position);

        if(position==mIndexer.getPositionForSection(section)){

            sortKey.setText(contact.getSortKey());

            linearKeyLayout.setVisibility(View.VISIBLE);

        }

        else{

            linearKeyLayout.setVisibility(View.GONE);

        }

        return layout;

    }

    

    public void setIndexer(SectionIndexer mIndexer){

        this.mIndexer=mIndexer;

    }

} 

与往常不同的是,这个适配器不仅要排列联系人信息,还需要加上一个判断是否显示或隐藏当前分组信息.

5.打开MainActivity.java

public class MainActivity extends Activity {

    //分组的布局

    private LinearLayout titleLayout;

    //分组上显示的字母

    private TextView title;

    //联系人ListView

    private ListView contactListView;

    //适配器

    private ContactAdapter mAdapter;

    //用于字母进行分组

    private AlphabetIndexer indexer;

    //存储卡中所有的联系人

    private List<Contact> contactList=new ArrayList<Contact>();

    //定义字母的排序规则

    private String alphabet = "#ABCDEFGHIJKLMNOPQRSTUVWXYZ";

    

    //上次第一个可见元素

    private int lastFirstVisibleItem=-1;

    

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        mAdapter=new ContactAdapter(this, R.layout.item, contactList);

        titleLayout=(LinearLayout) findViewById(R.id.title_layout);

        title=(TextView) findViewById(R.id.title);

        contactListView=(ListView) findViewById(R.id.lv);

        

        Uri uri=ContactsContract.CommonDataKinds.Phone.CONTENT_URI;

        Cursor cursor = getContentResolver().query(uri,

                new String[] { "display_name", "sort_key" }, null, null, "sort_key");

        if(cursor.moveToFirst()){

            do {

                String name=cursor.getString(0);

                String sort_name=getSortKey(cursor.getString(1));

                Contact contact=new Contact();

                contact.setName(name);

                contact.setSortKey(sort_name);

                contactList.add(contact);

            } while (cursor.moveToNext());

        }

        startManagingCursor(cursor);

        indexer=new AlphabetIndexer(cursor, 1, alphabet);

        mAdapter.setIndexer(indexer);

        if (contactList.size()>0) {

            setupContactListView();

        }

    }

    

    //为联系人ListView设置监听

    private void setupContactListView(){

        contactListView.setAdapter(mAdapter);

        contactListView.setOnScrollListener(new OnScrollListener() {

            @Override

            public void onScrollStateChanged(AbsListView arg0, int arg1) {

                

            }

            

            @Override

            public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {

                int section =indexer.getSectionForPosition(firstVisibleItem);

                int nextSectionPosition=indexer.getPositionForSection(section+1);

                if(firstVisibleItem!=lastFirstVisibleItem){

                    MarginLayoutParams params=(MarginLayoutParams) titleLayout.getLayoutParams();

                    params.topMargin=0;

                    titleLayout.setLayoutParams(params);

                    title.setText(String.valueOf(alphabet.charAt(section)));

                }

                if(nextSectionPosition==firstVisibleItem+1){

                    View viewChild=view.getChildAt(0);

                    if(viewChild!=null){

                        int titleHeight=titleLayout.getHeight();

                        int bottom=viewChild.getBottom();

                        MarginLayoutParams params=(MarginLayoutParams) titleLayout.getLayoutParams();

                        if(bottom<titleHeight){

                            float pushedDistance=bottom-titleHeight;

                            params.topMargin=(int) pushedDistance;

                            titleLayout.setLayoutParams(params);

                        }

                        else{

                            if(params.topMargin!=0){

                                params.topMargin=0;

                                titleLayout.setLayoutParams(params);

                            }

                        }

                    }

                }

                lastFirstVisibleItem=firstVisibleItem;

            }

        });

    }

    

    /**

     * 获取sort key的首个字符，如果是英文字母就直接返回，否则返回#。

     * 

     * @param sortKeyString

     *            数据库中读取出的sort key

     * @return 英文字母或者#

     */

    private String getSortKey(String sortKeyString) {

        String key = sortKeyString.substring(0, 1).toUpperCase();

        if (key.matches("[A-Z]")) {

            return key;

        }

        return "#";

    }

}

 

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