How to make sticky section headers (like iOS) in Android?

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死守一世寂寞
死守一世寂寞 2020-12-23 14:25

My specific question is: How I can achieve an effect like this: http://youtu.be/EJm7subFbQI

The bounce effect is not important, but i need the \"sticky\" effect for

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  •  暖寄归人
    2020-12-23 14:36

    EDIT: Had some free time to add the code of fully working example. Edited the answer accordingly.

    For those who don't want to use 3rd party code (or cannot use it directly, e.g. in Xamarin), this could be done fairly easily by hand. The idea is to use another ListView for the header. This list view contains only the header items. It will not be scrollable by the user (setEnabled(false)), but will be scrolled from code based on main lists' scrolling. So you will have two lists - headerListview and mainListview, and two corresponding adapters headerAdapter and mainAdapter. headerAdapter only returns section views, while mainAdapter supports two view types (section and item). You will need a method that takes a position in the main list and returns a corresponding position in the sections list.

    Main activity

    public class MainActivity extends AppCompatActivity {
    
        public static final int TYPE_SECTION = 0;
        public static final int TYPE_ITEM = 1;
    
        ListView mainListView;
        ListView headerListView;
        MainAdapter mainAdapter;
        HeaderAdapter headerAdapter;
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
    
            mainListView = (ListView)findViewById(R.id.list);
            headerListView = (ListView)findViewById(R.id.header);
            mainAdapter = new MainAdapter();
            headerAdapter = new HeaderAdapter();
    
            headerListView.setEnabled(false);
            headerListView.setAdapter(headerAdapter);
            mainListView.setAdapter(mainAdapter);
    
            mainListView.setOnScrollListener(new AbsListView.OnScrollListener(){
    
                @Override
                public void onScrollStateChanged(AbsListView view, int scrollState){
    
                }
    
                @Override
                public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
                    // this should return an index in the headers list, based one the index in the main list. The logic for this is highly dependent on your data.
                    int pos = mainAdapter.getSectionIndexForPosition(firstVisibleItem);
                    // this makes sure our headerListview shows the proper section (the one on the top of the mainListview)
                    headerListView.setSelection(pos);
    
                    // this makes sure that headerListview is scrolled exactly the same amount as the mainListview
                    if(mainAdapter.getItemViewType(firstVisibleItem + 1) == TYPE_SECTION){
                        headerListView.setSelectionFromTop(pos, mainListView.getChildAt(0).getTop());
                    }
                }
            });
        }
    
        public class MainAdapter extends BaseAdapter{
            int count = 30;
    
            @Override
            public int getItemViewType(int position){
                if((float)position / 10 == (int)((float)position/10)){
                    return TYPE_SECTION;
                }else{
                    return TYPE_ITEM;
                }
            }
    
            @Override
            public int getViewTypeCount(){ return 2; }
    
            @Override
            public int getCount() { return count - 1; }
    
            @Override
            public Object getItem(int position) { return null; }
    
            @Override
            public long getItemId(int position) { return position; }
    
            public int getSectionIndexForPosition(int position){ return position / 10; }
    
            @Override
            public View getView(int position, View convertView, ViewGroup parent) {
                View v =  getLayoutInflater().inflate(R.layout.item, parent, false);
                position++;
                if(getItemViewType(position) == TYPE_SECTION){
                    ((TextView)v.findViewById(R.id.text)).setText("SECTION "+position);
    
                }else{
                    ((TextView)v.findViewById(R.id.text)).setText("Item "+position);
                }
                return v;
            }
        }
    
        public class HeaderAdapter extends BaseAdapter{
            int count = 5;
    
            @Override
            public int getCount() { return count; }
    
            @Override
            public Object getItem(int position) { return null; }
    
            @Override
            public long getItemId(int position) { return position; }
    
            @Override
            public View getView(int position, View convertView, ViewGroup parent) {
                View v =  getLayoutInflater().inflate(R.layout.item, parent, false);
                ((TextView)v.findViewById(R.id.text)).setText("SECTION "+position*10);
                return v;
            }
        }
    
    }
    

    A couple of things to note here. We do not want to show the very first section in the main view list, because it would produce a duplicate (it's already shown in the header). To avoid that, in your mainAdapter.getCount():

    return actualCount - 1;
    

    and make sure the first line in your getView() method is

    position++;
    

    This way your main list will be rendering all cells but the first one.

    Another thing is that you want to make sure your headerListview's height matches the height of the list item. In this example the height is fixed, but it could be tricky if your items height is not set to an exact value in dp. Please refer to this answer for how to address this: https://stackoverflow.com/a/41577017/291688

    Main layout

    
    
        
    
        
    
    

    Item / header layout

    
    
        
    
    
    

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