How to get android mobile phone contacts and display them in letters (2)

How to get android mobile phone contacts and display them in letters (2)

The following describes how to categorize and display contacts with the same initials:

In the adapter implement SectionIndexer

In this way, the adapter must implement the following three interfaces:

@ Overridepublic Object [] getSections () {// collection of sections} @ Overridepublic int getPositionForSection (int section) {// location of the current section} @ Overridepublic int getSectionForPosition (int position) {// section information of the current position}

Therefore, we must process the data of the obtained local contact.

Define a section to store information:

 private class SectionTitle{    public String title;    public SectionTitle(){    title = "\";    }        public String toString(){    return title;    }    }

Define the following structure to obtain the information required to implement sectionIndexer: <喎?http: www.bkjia.com kf ware vc " target="_blank" class="keylink"> VcD4KPHA + Signature = "brush: java;"> private class ContactSectionMapper implements SectionIndexer {private SectionTitle [] mSections = null; private SparseIntArray mSectionPositionMap = null; private SparseIntArray Signature = null; public Functions (SectionTitle [] sectionDatas) {mSections = sectionDatas;} public void changeData (SparseIntArray sectionPositionMap, SparseIntArray positionSectionMap) {region = sectionPositionMap; region = positionSectionMap ;} @ Overridepublic Object [] getSections () {return mSections;}/*** locate the position corresponding to this section */@ Overridepublic int getPositionForSection (int section) {if (mSectionPositionMap = null) return-1; if (section = 0) return-1; return mSectionPositionMap. get (section,-1);}/*** locate the section corresponding to this position */@ Overridepublic int getSectionForPosition (int position) {if (mPositionSectionMap = null) return-1; if (position <= 0) return 0; return mPositionSectionMap. get (position,-1);}/*** @ param position * @ return */public boolean isSection (int position) {if (position = 0) return true; int sectionIdx = getSectionForPosition (position); int sectionPosition = getPositionForSection (sectionIdx); if (sectionIdx =-1 & sectionPosition =-1) return false; return (position = sectionPosition);} public String getSection (int position) {if (mSections = null) return NONE_ENGLISH_LETTER_TITLE; int sectionIndex = getSectionForPosition (position ); if (sectionIndex <0 | sectionIndex> = mSections. length) return NONE_ENGLISH_LETTER_TITLE; return mSections [sectionIndex]. toString ();}}
In the adapter, we reload the changeCursor method (called every time the cursor changes) to process and retrieve the initial information of the data.

@ Overridepublic void changeCursor (Cursor c) {processCursor (c); super. changeCursor (c);} private void processCursor (Cursor c) {/** define some variables */SparseIntArray sectionPositionMap = new SparseIntArray (); SparseIntArray positionSectionMap = new SparseIntArray (); for (int I = 0; I <mSectionDatas. length; I ++) {mSectionDatas [I]. title = "\";} if (c = null "| c. getCount () = 0 | c. isClosed () {mSection Mapper. changeData (sectionPositionMap, positionSectionMap); return;} String curtitle = "\"; int I = 0; int position = 0; while (c. moveToNext () {position = c. getPosition (); String curLetter = getTitle (getDisplayName (c); // you can check whether the first name of the current name is the beginning of the section. if (TextUtils. isEmpty (curtitle) "|! TextUtils. equals (curLetter, curtitle) {mSectionDatas [I]. title = curLetter; // The current name is sectionPositionMap at the beginning of section. put (I, position); curtitle = curLetter; I ++;} positionSectionMap. put (position, I-1) ;}for (; I <mSectionDatas. length; I ++) {mSectionDatas [I]. title = curtitle; sectionPositionMap. put (I, position);} mSectionMapper. changeData (sectionPositionMap, positionSectionMap );}

In adapter initialization:

protected final class ContactsAdapter extends ResourceCursorAdapter implements SectionIndexer,OnScrollListener {protected boolean mLoading = true;private ContactSectionMapper mSectionMapper = null;private SectionTitle[] mSectionDatas = null;private static final int SECTION_COUNT = 27;public ContactsAdapter(Context context) {super(context, R.layout.contacts_list_item_photo,null);mSectionDatas = new SectionTitle[SECTION_COUNT];for (int i = 0; i < SECTION_COUNT; i++) {mSectionDatas[i] = new SectionTitle();}mSectionMapper = new ContactSectionMapper(mSectionDatas);}

@Overridepublic Object[] getSections() {return mSectionMapper.getSections();}@Overridepublic int getPositionForSection(int section) {return mSectionMapper.getPositionForSection(section);}@Overridepublic int getSectionForPosition(int position) {return mSectionMapper.getSectionForPosition(position);}

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