我有一个ListView，它有两种类型的标题和放大器。在此我想要实现另一种类型的标头，称为StickyListHeader
嗯，实现2种类型的标题对我来说是一项复杂的任务。现在，实现StickyListHeader并不是一件容易的事。让每5个视图我都要添加一个StickyListHeader。
这是代码：
public class ContentsFragment extends ListFragment implements OnTouchListener,AbsListView.OnScrollListener {
private MyCustomAdapter mAdapter;
Activity temp = getActivity();
String []s = new String[500];
ArrayList<GS> q = new ArrayList<GS>();
ListView lv;
int count=0;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
DBAdapter db = DBAdapter.getDBAdapter(getActivity());
if (!db.checkDatabase())
db.createDatabase(getActivity());
db.openDatabase();
q = db.getData();
mAdapter = new MyCustomAdapter(getActivity());
mAdapter.addSeparatorItem(new ContentWrapper(q.get(0).getA_name(),null,null));
mAdapter.addItem(new ContentWrapper(q.get(0).getAS_name(), q.get(0).getDesc_art(),null));
for (int i = 1; i <= 14; i++) {
if (!(q.get(i).getA_name().trim().equals(q.get(i-1).getA_name().trim()))) {
mAdapter.addSeparatorItem(new ContentWrapper(q.get(i).getA_name(), null,null));
}
if(!(q.get(i).getExtra()==null))
mAdapter.addGraySeparatorItem(new ContentWrapper(q.get(i).getExtra(),null,null));
mAdapter.addItem(new ContentWrapper(q.get(i).getAS_name(), q.get(i).getDesc_art(),null));
}
for (int i = 15; i < 36; i++) {
if (!(q.get(i).getA_name().trim().equals(q.get(i-1).getA_name().trim()))) {
mAdapter.addSeparatorItem(new ContentWrapper(q.get(i).getA_name(), null,null));
}
if(!(q.get(i).getExtra()==null))
mAdapter.addGraySeparatorItem(new ContentWrapper(q.get(i).getExtra(),null,null));
mAdapter.addItem(new ContentWrapper(q.get(i).getAS_name(), q.get(i).getDesc_art(),null));
}
//Adapter Class
private class MyCustomAdapter extends BaseAdapter {
private static final int TYPE_ITEM = 0;
private static final int TYPE_SEPARATOR = 1;
private static final int TYPE_GRAY_SEPARATOR = 2;
private static final int TYPE_MAX_COUNT = TYPE_GRAY_SEPARATOR + 1;
private TreeSet<Integer> mGraySeparatorsSet = new TreeSet<Integer>();
private ArrayList<ContentWrapper> mData = new ArrayList<ContentWrapper>();
private LayoutInflater mInflater;
private TreeSet<Integer> mSeparatorsSet = new TreeSet<Integer>();
public MyCustomAdapter(Context context)
{
mInflater = LayoutInflater.from(context);
}
public void addItem(ContentWrapper value) {
mData.add(value);
notifyDataSetChanged();
}
public void addSeparatorItem(ContentWrapper value) {
mData.add(value);
// save separator position
mSeparatorsSet.add(mData.size() - 1);
notifyDataSetChanged();
}
public void addGraySeparatorItem(ContentWrapper value) {
mData.add(value);
// save separator position
mGraySeparatorsSet.add(mData.size() - 1);
notifyDataSetChanged();
}
public ContentWrapper getItem(int position) {
return mData.get(position);
}
@Override
public int getItemViewType(int position) {
int viewType = TYPE_ITEM;
if(mSeparatorsSet.contains(position))
viewType = TYPE_SEPARATOR;
else if(mGraySeparatorsSet.contains(position)) {
viewType = TYPE_GRAY_SEPARATOR;
}
return viewType;
// return mSeparatorsSet.contains(position) ? TYPE_SEPARATOR : TYPE_ITEM;
}
@Override
public int getViewTypeCount() {
return TYPE_MAX_COUNT;
}
public int getCount() {
return mData.size();
}
public long getItemId(int position) {
Log.v("getItemId Position", ""+position);
return position;
}
public View getView(final int position, View convertView, ViewGroup parent) {
ViewHolder holder = null;
int type = getItemViewType(position);
if (convertView == null) {
holder = new ViewHolder();
switch (type) {
case TYPE_ITEM:
convertView = mInflater.inflate(R.layout.white, null);
holder.textView = (TextView)convertView.findViewById(R.id.text);
break;
case TYPE_SEPARATOR:
convertView = mInflater.inflate(R.layout.black, null);
holder.textView = (TextView)convertView.findViewById(R.id.textSeparator);
break;
case 2:
convertView = mInflater.inflate(R.layout.gray, null);
holder.textView = (TextView)convertView.findViewById(R.id.textViewGray);
break;
}
convertView.setTag(holder);
} else {
holder = (ViewHolder)convertView.getTag();
} holder.textView.setText(mData.get(position).getItem());
getListView().setFastScrollEnabled(true);
if (type == TYPE_ITEM) {
holder.textView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
builder.setIcon(R.drawable.ic_launcher);
final String title = mData.get(position).getItem();
builder.setTitle(title);
builder.setMessage(mData.get(position).getItemDescription());
builder.setCancelable(false);
builder.setPositiveButton("Ok", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
});
AlertDialog alertDialog = builder.create();
alertDialog.setOnShowListener(new DialogInterface.OnShowListener() {
@Override
public void onShow(DialogInterface dialog) {
AlertDialog alertDialog = (AlertDialog) dialog;
ViewGroup viewGroup = (ViewGroup) alertDialog.getWindow()
.getDecorView();
TextView textView = findTextViewWithTitle(viewGroup, title);
if (textView != null) {
textView.setEllipsize(null);
textView.setMaxHeight((int) (100 * alertDialog.getContext().getResources().getDisplayMetrics().density));
textView.setMovementMethod(new ScrollingMovementMethod());
}
}
});
alertDialog.show();
}
private TextView findTextViewWithTitle(ViewGroup viewGroup, String title) {
for (int i = 0, N = viewGroup.getChildCount(); i < N; i++) {
View child = viewGroup.getChildAt(i);
if (child instanceof TextView) {
TextView textView = (TextView) child;
if (textView.getText().equals(title)) {
return textView;
}
} else if (child instanceof ViewGroup) {
ViewGroup vGroup = (ViewGroup) child;
return findTextViewWithTitle(vGroup, title);
}
}
return null;
}
});
}else if(type == 1) {
holder.textView.setOnClickListener(null);
}
else
{
holder.textView.setOnClickListener(null);
}
return convertView;
}
}
public static class ViewHolder {
public TextView textView;
public TextView header;
int previousTop = 0;
}
public boolean onTouch(View v, MotionEvent event) {
return false;
}
@Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
}
@Override
public void onScroll(AbsListView view, int firstVisibleItem,
int visibleItemCount, int totalItemCount) {
//the listview has only few children (of course according to the height of each child) who are visible
for(int i=0; i < getListView().getChildCount(); i++){
View child = getListView().getChildAt(i);
ViewHolder holder = (ViewHolder) child.getTag();
//if the view is the first item at the top we will do some processing
if(i == 0){
boolean isAtBottom = child.getHeight() <= holder.header.getBottom();
int offset = holder.previousTop - child.getTop();
if(!(isAtBottom && offset > 0)){
holder.previousTop = child.getTop();
holder.header.offsetTopAndBottom(offset);
holder.header.invalidate();
}
} //if the view is not the first item it "may" need some correction because of view re-use
else if (holder.header.getTop() != 0) {
int offset = -1 * holder.header.getTop();
holder.header.offsetTopAndBottom(offset);
holder.previousTop = 0;
holder.header.invalidate();
}
}
}
}
正如您所看到的StickyListHeader我实现了onScroll()方法。
现在我认为修改必须在课程MyCustomAdapter构造函数＆amp;在getView()方法中，我正在考虑这个example＆amp;它声明我们必须处理构造函数，getView（）＆amp; onScroll（）。
任何人都可以告诉我应该修改什么来完成我的任务。
谢谢