首先看看实现的效果
可以看出要实现上面效果，有三个步骤：
1.汉字转化为拼音，并且根据首字母排序
2.用ItemDecoration实现字母行的显示
3.自定义实现右侧的按字母导航栏
当然重点讲讲ItemDecoration的实现。都知道RecyclerView本身都没有分割线，需要分割线都是在item中画一条线或者使用ItemDecoration来实现分割线。在RecyclerView中我们可以给每一个item都添加ItemDecoration，所以可以自定义ItemDecoration来实现各种我们所需要的效果。
ItemDecoration
ItemDecoration是RecyclerView内部的一个抽象类，要实现这个抽象类自然需要实现内部的抽象方法，除了deprecated的方法只有下面三个方法：
1.void getItemOffsets(Rect outRect, View view, RecyclerView parent, State state)
这个方法是用来指定每一个的item对应decoration的大小区域，主要实现方式就是设置outRect的left、top、right、bottom，如果一个item不需要decoration把outRect的上下左右设置为0即可。盗用网上一张图看看outRect具体什么意思
2.void onDraw(Canvas c, RecyclerView parent, State state)
onDraw方法看名字大家都应该很熟悉，这个方法自然是用来画具体的ItemDecoration的，绘制的内容是显示在itemView的下层。下层什么意思，待会来看看。
3.void onDrawOver(Canvas c, RecyclerView parent, State state)
也是一个绘制的方法，不过是绘制在itemView的上层
以上三个方法的调用顺序也就是按照上面的排列的顺序来调用的。
首先来看看用ItemDecoration实现的分割线DividerItemDecoration
public class DividerItemDecoration extends RecyclerView.ItemDecoration { private static final int[] ATTRS = new int[]{android.R.attr.listDivider}; public static final int HORIZONTAL_LIST = LinearLayoutManager.HORIZONTAL; public static final int VERTICAL_LIST = LinearLayoutManager.VERTICAL; private Drawable mDivider; private int mOrientation; public DividerItemDecoration(Context context, int orientation) { //获取系统的divider final TypedArray a = context.obtainStyledAttributes(ATTRS); mDivider = a.getDrawable(0); a.recycle(); setOrientation(orientation); } public void setOrientation(int orientation) { if (orientation != HORIZONTAL_LIST && orientation != VERTICAL_LIST) { throw new IllegalArgumentException("invalid orientation"); } mOrientation = orientation; } @Override public void onDraw(Canvas c, RecyclerView parent, RecyclerView.State state) { super.onDraw(c, parent, state); if (mOrientation == VERTICAL_LIST) { drawVertical(c, parent); } else { drawHorizontal(c, parent); } } //画竖直分割线 public void drawVertical(Canvas c, RecyclerView parent) { //左边缘距离RecyclerView左边的距离 final int left = parent.getPaddingLeft(); //右边缘距离RecyclerView右边边的距离 final int right = parent.getWidth() - parent.getPaddingRight(); final int childCount = parent.getChildCount(); for (int i = 0; i < childCount; i++) { final View child = parent.getChildAt(i); final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child .getLayoutParams(); final int top = child.getBottom() + params.bottomMargin; final int bottom; //去掉最后一条的分割线 if (i == childCount - 1) {//bottom和top相等，即高度为0 不显示 bottom = top; } else { bottom = top + mDivider.getIntrinsicHeight(); } mDivider.setBounds(left, top, right, bottom); mDivider.draw(c); } } //画水平分割线 public void drawHorizontal(Canvas c, RecyclerView parent) { final int top = parent.getPaddingTop(); final int bottom = parent.getHeight() - parent.getPaddingBottom(); final int childCount = parent.getChildCount(); for (int i = 0; i < childCount; i++) { final View child = parent.getChildAt(i); final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child .getLayoutParams(); final int left = child.getRight() + params.rightMargin; final int right = left + mDivider.getIntrinsicHeight(); mDivider.setBounds(left, top, right, bottom); mDivider.draw(c); } } @Override public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) { super.getItemOffsets(outRect, view, parent, state); if (mOrientation == VERTICAL_LIST) { outRect.set(0, 0, 0, mDivider.getIntrinsicHeight()); } else { outRect.set(0, 0, mDivider.getIntrinsicWidth(), 0); } }}
主要实现了getItemOffsets和onDraw方法，因为这两个方法已经能满足了，自然不需要全部方法实现。在getItemOffsets方法中判断是竖直方向还是水平方向的分割线，竖直方向只需要在outRect的bottom加上分割线的宽度即可，当然水平分割线在右边加上就OK。在onDraw方法中具体的画出分割线，不知道大家有没有想过这里的分割线高度和outRect中设置的高度有什么关系，那么下面修改一下代码实验一下。
在上面onDraw画竖直分割线的方法中，把分割线高度加上80px，即：
mDivider.setBounds(left, top, right, bottom+80);
效果没变化？意思是onDraw里面画的区域大小不会超过outRect设置的大小吗？记得之前说过，onDraw方法绘制的内容是在itemView的下层的，会不会是被itemView遮挡而没有显示出来呢，那么下面我们把itemView的背景色改为透明，看看效果
android:background="@android:color/transparent"
这次看到了不同了吧，正是我们所猜想的那样。也就证明了onDraw方法显示的内容实在itemView的下层，同时它绘制的内容并不是不会超过outRect指定的区域，而outRect指定的区域也是实际分配给ItemDecoration的区域，在这个区域绘制才不会影响itemView，所以onDraw绘制的内容我们应该要保持和outRect给定的区域是相同的。
显示字母的ItemDecoration
现在来看看显示字母的ItemDecoration是怎么实现的。看上面的效果可以发现，最上面始终显示了一个ItemDecoration，上面说过onDrawOver方法绘制的内容是显示在最上层，所以用这个方法来绘制最上面再适合不过了。其他itemView显示字母的ItemDecoration也并不是采用onDraw方法绘制，而是用xml实现的，因为采用xml方式来实现可以更方便的来定制ItemDecoration的内容，也可以实现其中的点击事件。
在看ItemDecoration之前，先看看所用到的一个接口和RecyclerView的Adapter
public interface StickyHeaderAdapter<T extends RecyclerView.ViewHolder> { String getHeaderId(int position); T onCreateHeaderViewHolder(ViewGroup parent); void onBindHeaderViewHolder(T viewholder, int position);}
这个接口里面有三个方法，第一个方法是获取headerId，因为在显示是不可能每一个item都要显示decoration，只有每种首字母第一个才显示，所用这里需要一个id来判断是否需要设置ItemDecoration。后面两个方法是仿照RecyclerView.Adapter的写的，因为我们采用ItemDecoration布局用xml实现，如果需要显示的ItemDecoration很多的话，每次都需要去用LayoutInflater去加载布局，显然不够优雅，所用用holder机制来实现复用。下面来看看我们的Adapter
/** * Created by lzy . * Date: 16/11/24 */public class MedicineAdapter extends RecyclerView.Adapter<MedicineAdapter.ViewHolder> implements StickyHeaderAdapter<MedicineAdapter.HeaderHolder> { private Context mContext; private List<MedicineBean> mDatas; private LayoutInflater mInflater; private int i; public MedicineAdapter(Context mContext, List<MedicineBean> mDatas) { this.mContext = mContext; this.mDatas = mDatas; mInflater = LayoutInflater.from(mContext); } @Override public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { return new ViewHolder(mInflater.inflate(R.layout.item_medicine, parent, false)); } @Override public void onBindViewHolder(final ViewHolder holder, final int position) { final MedicineBean MedicineBean = mDatas.get(position); holder.tvName.setText(MedicineBean.getName()); } @Override public int getItemCount() { return mDatas != null ? mDatas.size() : 0; } @Override public String getHeaderId(int position) { return mDatas.get(position).getLetter(); } @Override//生成header的布局 public HeaderHolder onCreateHeaderViewHolder(ViewGroup parent) { return new HeaderHolder(mInflater.inflate(R.layout.item_decoration, parent, false)); } @Override//绑定header的数据 public void onBindHeaderViewHolder(HeaderHolder viewholder, int position) { viewholder.header.setText(mDatas.get(position).getLetter()); } /** * 根据分类的首字母获取其第一次出现该首字母的位置 */ public int getPositionForSection(String section) { for (int i = 0; i < mDatas.size(); i++) { String sortStr = mDatas.get(i).getLetter(); if (sortStr.equals(section)) { return i; } } return -1; } public static class ViewHolder extends RecyclerView.ViewHolder { TextView tvName; public ViewHolder(View itemView) { super(itemView); tvName = (TextView) itemView.findViewById(R.id.name); } } public static class HeaderHolder extends RecyclerView.ViewHolder { public TextView header; public HeaderHolder(View itemView) { super(itemView); header = (TextView) itemView; } }}
可以看到这个Adapter实现了之前上面的接口，接口的实现方式和普通的Adapter的实现都类似在onCreateHeaderViewHolder中加载xml文件，在onBindHeaderViewHolder中加载数据，HeaderHolder也是一样的，headerId是采用的一个letter的，也就是每一条的首字母。下面看看ItemDecoration是怎么实现的。
getItemOffsets方法
首先看看第一个getItemOffsets方法的实现
@Override public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) { super.getItemOffsets(outRect, view, parent, state); //得到该item所在的位置 int position = parent.getChildAdapterPosition(view); int headerHeight = 0; //在使用adapterPosition时最好的加上这个判断 if (position != RecyclerView.NO_POSITION && hasHeader(position)) { //获取到ItemDecoration所需要的高度 View header = getHeader(parent, position).itemView; headerHeight = header.getHeight(); } outRect.set(0, headerHeight, 0, 0); }
很简单，就是判断如果这个item需要ItemDecoration就获取到header的高度，设置给outRect
判断是否需要header
判断是否需要header的方法，之前不是在Adapter里面写了getHeaderId的方法吗，这里就用到了，根据前两个headerId是否相同来判断是否需要设置ItemDecoration
private boolean hasHeader(int position) { if (position == 0) {//第一个位置必然有 return true; } //判断和上一个的id不同则有header int previous = position - 1; return !mAdapter.getHeaderId(position).equals(mAdapter.getHeaderId(previous)); }
获取Header的方法
private RecyclerView.ViewHolder getHeader(RecyclerView parent, int position) { //创建HeaderViewHolder MedicineAdapter.HeaderHolder holder = mAdapter.onCreateHeaderViewHolder(parent); final View header = holder.itemView; //绑定数据 mAdapter.onBindHeaderViewHolder(holder, position); //测量View并且layout int widthSpec = View.MeasureSpec.makeMeasureSpec(parent.getWidth(), View.MeasureSpec.EXACTLY); int heightSpec = View.MeasureSpec.makeMeasureSpec(parent.getHeight(), View.MeasureSpec.UNSPECIFIED); //根据父View的MeasureSpec和子view自身的LayoutParams以及padding来获取子View的MeasureSpec int childWidth = ViewGroup.getChildMeasureSpec(widthSpec, parent.getPaddingLeft() + parent.getPaddingRight(), header.getLayoutParams().width); int childHeight = ViewGroup.getChildMeasureSpec(heightSpec, parent.getPaddingTop() + parent.getPaddingBottom(), header.getLayoutParams().height); //进行测量 header.measure(childWidth, childHeight); //根据测量后的宽高放置位置 header.layout(0, 0, header.getMeasuredWidth(), header.getMeasuredHeight()); return holder; }
在这里面调用了之前Adapter实现接口里面的方法，创建了ViewHolder，绑定了数据。都知道自定义view需要实现onMeasure、onLayout、onDraw方法，所以在这里对它进行了测量和放置，而draw是在onDrawOver里面实现的。对这里熟悉的可以去看看相关的知识点。
onDrawOver方法
@Override public void onDrawOver(Canvas c, RecyclerView parent, RecyclerView.State state) { final int count = parent.getChildCount(); for (int layoutPos = 0; layoutPos < count; layoutPos++) { final View child = parent.getChildAt(layoutPos); final int adapterPos = parent.getChildAdapterPosition(child); //只有在最上面一个item或者有header的item才绘制ItemDecoration if (adapterPos != RecyclerView.NO_POSITION && (layoutPos == 0 || hasHeader(adapterPos))) { View header = getHeader(parent, adapterPos).itemView; c.save(); final int left = child.getLeft(); final int top = getHeaderTop(parent, child, header, adapterPos, layoutPos); c.translate(left, top); header.setTranslationX(left); header.setTranslationY(top); header.draw(c); c.restore(); } } }
这里就是一个循环，在需要Header的地方进行绘制，当然需要把画布移动到要绘制的位置，主要是确定它距离顶部的大小。
private int getHeaderTop(RecyclerView parent, View child, View header, int adapterPos, int layoutPos) { int headerHeight = header.getHeight(); int top = ((int) child.getY()) - headerHeight; if (layoutPos == 0) {//处理最上面两个ItemDecoration切换时 final int count = parent.getChildCount(); final String currentId = mAdapter.getHeaderId(adapterPos); for (int i = 1; i < count; i++) { int adapterPosHere = parent.getChildAdapterPosition(parent.getChildAt(i)); if (adapterPosHere != RecyclerView.NO_POSITION) { String nextId = mAdapter.getHeaderId(adapterPosHere); if (!nextId.equals(currentId)) {//找到下一个不同类的view final View next = parent.getChildAt(i); //这里计算offset画个图会很清楚 final int offset = ((int) next.getY()) - (headerHeight + getHeader(parent, adapterPosHere).itemView.getHeight()); if (offset < 0) {//如果大于0的话，此时并没有切换 return offset; } else { break; } } } } //top不能小于0，否则最上面的ItemDecoration不会一直存在 top = Math.max(0, top); } return top; }
这里的逻辑是这样的：
1.当此view不是最上面的显示的时候，header距离顶部直接就是此view距离顶部距离减去header的高度即可2.当此view是最上面的view的时候，首先用for循环找到它下一个和它headerId不同的第一个view，利用找到的这个view和它本身来计算出它的header距离顶部的距离，当这个距离大于0时，代表此view的header还全部显示出来，这时直接用上面的方式获取这个距离，当这个距离小于0时就是我们所希望的。OK完成，下面贴出ItemDecoration的所以代码
/** * Created by lzy on 2016/11/23. */public class StickyItemDecoration extends RecyclerView.ItemDecoration { private static final String TAG = "lzy"; private MedicineAdapter mAdapter; public StickyItemDecoration(MedicineAdapter mAdapter) { super(); this.mAdapter = mAdapter; } //最后调用 绘制顶部固定的header @Override public void onDrawOver(Canvas c, RecyclerView parent, RecyclerView.State state) { final int count = parent.getChildCount(); for (int layoutPos = 0; layoutPos < count; layoutPos++) { final View child = parent.getChildAt(layoutPos); final int adapterPos = parent.getChildAdapterPosition(child); //只有在最上面一个item或者有header的item才绘制ItemDecoration if (adapterPos != RecyclerView.NO_POSITION && (layoutPos == 0 || hasHeader(adapterPos))) { View header = getHeader(parent, adapterPos).itemView; c.save(); final int left = child.getLeft(); final int top = getHeaderTop(parent, child, header, adapterPos, layoutPos); c.translate(left, top); header.setTranslationX(left); header.setTranslationY(top); header.draw(c); c.restore(); } } } @Override public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) { super.getItemOffsets(outRect, view, parent, state); //得到该item所在的位置 int position = parent.getChildAdapterPosition(view); int headerHeight = 0; //在使用adapterPosition时最好的加上这个判断 if (position != RecyclerView.NO_POSITION && hasHeader(position)) { //获取到ItemDecoration所需要的高度 View header = getHeader(parent, position).itemView; headerHeight = header.getHeight(); } outRect.set(0, headerHeight, 0, 0); } /** * 判断是否有header * * @param position * @return */ private boolean hasHeader(int position) { if (position == 0) {//第一个位置必然有 return true; } //判断和上一个的id不同则有header int previous = position - 1; return !mAdapter.getHeaderId(position).equals(mAdapter.getHeaderId(previous)); } /** * 获得自定义的Header * * @param parent * @param position * @return */ private RecyclerView.ViewHolder getHeader(RecyclerView parent, int position) { //创建HeaderViewHolder MedicineAdapter.HeaderHolder holder = mAdapter.onCreateHeaderViewHolder(parent); final View header = holder.itemView; //绑定数据 mAdapter.onBindHeaderViewHolder(holder, position); //测量View并且layout int widthSpec = View.MeasureSpec.makeMeasureSpec(parent.getWidth(), View.MeasureSpec.EXACTLY); int heightSpec = View.MeasureSpec.makeMeasureSpec(parent.getHeight(), View.MeasureSpec.UNSPECIFIED); //根据父View的MeasureSpec和子view自身的LayoutParams以及padding来获取子View的MeasureSpec int childWidth = ViewGroup.getChildMeasureSpec(widthSpec, parent.getPaddingLeft() + parent.getPaddingRight(), header.getLayoutParams().width); int childHeight = ViewGroup.getChildMeasureSpec(heightSpec, parent.getPaddingTop() + parent.getPaddingBottom(), header.getLayoutParams().height); //进行测量 header.measure(childWidth, childHeight); //根据测量后的宽高放置位置 header.layout(0, 0, header.getMeasuredWidth(), header.getMeasuredHeight()); return holder; } /** * 计算距离顶部的高度 * * @param parent * @param child * @param header * @param adapterPos * @param layoutPos * @return */ private int getHeaderTop(RecyclerView parent, View child, View header, int adapterPos, int layoutPos) { int headerHeight = header.getHeight(); int top = ((int) child.getY()) - headerHeight; if (layoutPos == 0) {//处理最上面两个ItemDecoration切换时 final int count = parent.getChildCount(); final String currentId = mAdapter.getHeaderId(adapterPos); for (int i = 1; i < count; i++) { int adapterPosHere = parent.getChildAdapterPosition(parent.getChildAt(i)); if (adapterPosHere != RecyclerView.NO_POSITION) { String nextId = mAdapter.getHeaderId(adapterPosHere); //找到下一个不同类的view if (!nextId.equals(currentId)) { final View next = parent.getChildAt(i); //这里计算offset画个图会很清楚 final int offset = ((int) next.getY()) - (headerHeight + getHeader(parent, adapterPosHere).itemView.getHeight()); if (offset < 0) {//如果大于0的话，此时并没有切换 return offset; } else { break; } } } } //top不能小于0，否则最上面的ItemDecoration不会一直存在 top = Math.max(0, top); } return top; }}
汉字转拼音
通过一个三方的类库pinyin4j来实现，这里就是调用方法PinyinHelper.toHanyuPinyinStringArray获取一个汉字的拼音，然后得到第一个英文字母并转化为大写
private List<MedicineBean> filledData(String[] data) { List<MedicineBean> mSortList = new ArrayList<MedicineBean>(); for (int i = 0; i < data.length; i++) { MedicineBean medicineBean = new MedicineBean(); medicineBean.setName(data[i]); //汉字转换成拼音 String[] pinyin = PinyinHelper.toHanyuPinyinStringArray(data[i].toCharArray()[0]); String sortString = pinyin[0].substring(0, 1).toUpperCase(); // 正则表达式，判断首字母是否是英文字母 if (sortString.matches("[A-Z]")) { medicineBean.setLetter(sortString.toUpperCase()); } else { medicineBean.setLetter("#"); } mSortList.add(medicineBean); } return mSortList; }
右边的字母导航栏
public class SideBar extends View { // 触摸事件 private OnTouchingLetterChangedListener onTouchingLetterChangedListener; // 26个字母 public static String[] b = {"A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z", "#"}; private int choose = -1;// 选中 private Paint paint = new Paint(); private TextView mTextDialog; public void setTextView(TextView mTextDialog) { this.mTextDialog = mTextDialog; } public SideBar(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); } public SideBar(Context context, AttributeSet attrs) { super(context, attrs); } public SideBar(Context context) { super(context); } @Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); // 获取焦点改变背景颜色. int height = getHeight();// 获取对应高度 int width = getWidth(); // 获取对应宽度 int singleHeight = height / b.length;// 获取每一个字母的高度 for (int i = 0; i < b.length; i++) { paint.setColor(Color.rgb(33, 65, 98)); // paint.setColor(Color.WHITE); paint.setTypeface(Typeface.DEFAULT_BOLD); paint.setAntiAlias(true); paint.setTextSize(20); // 选中的状态 if (i == choose) { paint.setColor(Color.parseColor("#3399ff")); paint.setFakeBoldText(true); } // x坐标等于中间-字符串宽度的一半. float xPos = width / 2 - paint.measureText(b[i]) / 2; float yPos = singleHeight * i + singleHeight; canvas.drawText(b[i], xPos, yPos, paint); paint.reset();// 重置画笔 } } @Override public boolean dispatchTouchEvent(MotionEvent event) { final int action = event.getAction(); final float y = event.getY();// 点击y坐标 final int oldChoose = choose; final OnTouchingLetterChangedListener listener = onTouchingLetterChangedListener; final int c = (int) (y / getHeight() * b.length);// 点击y坐标所占总高度的比例*b数组的长度就等于点击b中的个数. switch (action) { case MotionEvent.ACTION_UP: setBackgroundDrawable(new ColorDrawable(0x00000000)); choose = -1;// invalidate(); if (mTextDialog != null) { mTextDialog.setVisibility(View.INVISIBLE); } break; default: setBackgroundColor(Color.parseColor("#808080")); if (oldChoose != c) { if (c >= 0 && c < b.length) { if (listener != null) { listener.onTouchingLetterChanged(b[c]); } if (mTextDialog != null) { mTextDialog.setText(b[c]); mTextDialog.setVisibility(View.VISIBLE); } choose = c; invalidate(); } } break; } return true; } /** * 向外公开的方法 * * @param onTouchingLetterChangedListener */ public void setOnTouchingLetterChangedListener( OnTouchingLetterChangedListener onTouchingLetterChangedListener) { this.onTouchingLetterChangedListener = onTouchingLetterChangedListener; } /** * 接口 * * @author coder */ public interface OnTouchingLetterChangedListener { void onTouchingLetterChanged(String s); }}
这是在网上找的一个类，相信大家都能看懂，就不多说了，最后贴出MainActivity
public class MainActivity extends AppCompatActivity { private String[] mData = {"阿魏八味丸", "阿昔洛韦眼膏", "艾司洛尔", "安吖啶注射液", "阿达帕林", "参茸追风酒", "草乌", "石斛夜光丸", "骨质增生片", "乌鸡白凤丸", "人参益母丸", "补脾益肠丸", "丹参片", "小金丸", "妇宁康", "糖脉康", "菲伯瑞", "乙肝解毒片", "脑血栓片"}; private static final String TAG = "lzy"; private RecyclerView mRecyclerView; private SideBar sideBar; private StickyItemDecoration mDecoration; private PinyinComparator pinyinComparator; private MedicineAdapter medicineAdapter; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); mRecyclerView = (RecyclerView) findViewById(R.id.rv); mRecyclerView.setLayoutManager(new LinearLayoutManager(this)); //按照字母排序 pinyinComparator = new PinyinComparator(); List<MedicineBean> data = filledData(mData); Collections.sort(data, pinyinComparator); medicineAdapter = new MedicineAdapter(this, data); mRecyclerView.setAdapter(medicineAdapter); mDecoration = new StickyItemDecoration(medicineAdapter); mRecyclerView.addItemDecoration(mDecoration); //添加分割线 mRecyclerView.addItemDecoration(new DividerItemDecoration(MainActivity.this, DividerItemDecoration.VERTICAL_LIST)); sideBar = (SideBar) findViewById(R.id.sideBar); sideBar.setTextView((TextView) findViewById(R.id.dialog)); //设置右侧触摸监听 sideBar.setOnTouchingLetterChangedListener(new SideBar.OnTouchingLetterChangedListener() { @Override public void onTouchingLetterChanged(String s) { //该字母首次出现的位置 int position = medicineAdapter.getPositionForSection(s); if (position != -1) { mRecyclerView.scrollToPosition(position); } } }); } /** * 填充数据 * * @param data * @return */ private List<MedicineBean> filledData(String[] data) { List<MedicineBean> mSortList = new ArrayList<MedicineBean>(); for (int i = 0; i < data.length; i++) { MedicineBean medicineBean = new MedicineBean(); medicineBean.setName(data[i]); //汉字转换成拼音 String[] pinyin = PinyinHelper.toHanyuPinyinStringArray(data[i].toCharArray()[0]); String sortString = pinyin[0].substring(0, 1).toUpperCase(); // 正则表达式，判断首字母是否是英文字母 if (sortString.matches("[A-Z]")) { medicineBean.setLetter(sortString.toUpperCase()); } else { medicineBean.setLetter("#"); } mSortList.add(medicineBean); } return mSortList; }}
最后贴出源码的下载地址：http://download.csdn.net/detail/lylodyf/9695270
不敢接受失败的人，往往是那些追求完美的人，
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