最近需要实现一个城市列表的快速索引功能。类似于联系人应用，根据姓名首字母快速索引功能。
列表‘特征’和分组首项进行关联
for (int i = 0; i < mCitys.size(); i++) {
City city = mCitys.get(i);
String cityId = city.getId();
if(cityId == null || "".equals(cityId)) continue;
String section = cityId.toUpperCase().substring(0, 1);
if(!indexMap.containsKey(section)){
indexMap.put(section, i);
}
}
@Override
protected void onDraw(Canvas canvas) {
heightCenter = getMeasuredHeight()/2 - preHeight*WORDS.length/2;
for (int i = 0; i < WORDS.length; i++) {
canvas.drawText(String.valueOf(WORDS[i]), getMeasuredWidth()/2, preHeight
+ (i * preHeight) + heightCenter, mPaint);
}
super.onDraw(canvas);
} public boolean onTouchEvent(MotionEvent event) {
int startY = (int) event.getY() - heightCenter;
int index = startY / preHeight;
if (index >= WORDS.length) {
index = WORDS.length - 1;
} else if (index < 0) {
index = 0;
}
if (event.getAction() == MotionEvent.ACTION_DOWN || event.getAction() == MotionEvent.ACTION_MOVE) {
int position = mSectionIndexter.getStartPositionOfSection(String.valueOf(WORDS[index]));
if (position == -1) {
return true;
}
mListView.setSelection(position);
}
return true;
}
源码：https://github.com/TUBB/CityIndex
原文：http://blog.csdn.net/tu_bingbing/article/details/42151909