ListView局部刷新

前言：

今天讲一个ListView优化的小技巧，很多时候，我们不需要刷新整个ListView,只是想刷新某一个Item，那么，这个技巧就派上用场了：

一：比如列表有收藏按钮，当前页面收藏

private List<Map<String, String>> mList = new ArrayList<>();...走收藏接口，在成功后  mList.get(position).put("favorites", "1");  notifyDataSetChanged();

二：比如列表有收藏按钮，下个页面进行收藏

这种情况下，收藏成功后，返回需要刷新上一个页面状态

DataAdapter

Intent intent = new Intent(activity, NextActivity.class); intent.putExtra("userhead", doctorList.get(position) .getHeadImg()); intent.putExtra("username", doctorList.get(position) .getName()); intent.putExtra("userId", doctorList.get(position) .getUserinfo_djid()); intent.putExtra("position", position); startActivityForResult(intent,AppConfig.REQUEST_CODE_DIALOGUE);

NextActivity.class

收藏成功后，返回Intent intent;intent = new Intent();Bundle bundle = new Bundle();bundle.putInt("position", position);intent.putExtras(bundle);setResult(RESULT_OK, intent); finish();

onActivityResult

public void onActivityResult(int requestCode, int resultCode, Intent data) {            if (requestCode == AppConfig.REQUEST_CODE_DIALOGUE                && resultCode == RESULT_OK) {            int position = data.getExtras().getInt("position");            Object object = dataAdapter.getItem(position);            if (object instanceof DoctorList) {                DoctorList doctorList = (DoctorList) object;                doctorList.setUnreadnum("0");                dataAdapter.notifyDataSetChanged();            }        }        super.onActivityResult(requestCode, resultCode, data);    }

DoctorList

class DialogueBean {    private String result;    private ArrayList<DoctorList> doctorList;public class DoctorList implements Serializable {        private String userinfo_djid;        private String headImg;        private String name;        private String unreadnum;        private String infoContent;        private String sendDate;        private String ky_flag;        private String tobewritten;}}

三：以上只是未重新请求接口下刷新View，未真正局部刷新

• ListView局部刷新

3、以上只是未重新请求接口下刷新View，未真正局部刷新ListView局部刷新

 private List<Map<String, Object>> mData;   private ListView mListView;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        mData = getData();        MyAdapter adapter = new MyAdapter(this);        mListView = (ListView) findViewById(R.id.listView);        mListView.setAdapter(adapter);    }    private List<Map<String, Object>> getData() {        List<Map<String, Object>> list = new ArrayList<>();        Map<String, Object> map;        for (int i = 0; i < 50; i++) {            map = new HashMap<>();            map.put("title", "G" + i);            list.add(map);        }        return list;    }    public class MyAdapter extends BaseAdapter {        private LayoutInflater mInflater;        public MyAdapter(Context context) {            this.mInflater = LayoutInflater.from(context);        }        @Override        public int getCount() {            return mData.size();        }        @Override        public Object getItem(int arg0) {            return mData.get(arg0);        }        @Override        public long getItemId(int arg0) {            return arg0;        }        @Override        public View getView(final int position, View convertView, ViewGroup parent) {            Log.d("wxl", "getView=" + position);            ViewHolder holder = null;            if (convertView == null) {                holder = new ViewHolder();                convertView = mInflater.inflate(R.layout.listview_item, null);                holder.textview = (TextView) convertView.findViewById(R.id.textview);                convertView.setTag(holder);            } else {                holder = (ViewHolder) convertView.getTag();            }            holder.textview.setText((String) mData.get(position).get("title"));            convertView.setOnClickListener(new View.OnClickListener() {                @Override                public void onClick(View v) {                    updateItemView(position);//状态改变时，调用，这里是为了演示方便                }            });            return convertView;        }        public class ViewHolder {            public TextView textview;        }    }    public void updateItemView(int position) {        //得到第一个可显示控件的位置，        int visiblePosition = mListView.getFirstVisiblePosition();        //只有当要更新的view在可见的位置时才更新，不可见时，跳过不更新        int index = position - visiblePosition;        if (index >= 0) {            //得到要更新的item的view            View view = mListView.getChildAt(index);            //从view中取得holder            MyAdapter.ViewHolder holder = (MyAdapter.ViewHolder) view.getTag();            holder.textview.setText("测试数据");            mData.get(index).put("title", "测试数据");        }    }}

listview_item.xml

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="vertical">    <TextView        android:id="@+id/textview"        android:layout_width="match_parent"        android:layout_height="60dp"        android:layout_gravity="center_vertical"        android:gravity="center_vertical" /></LinearLayout>

• RecyclerView局部刷新

RecyclerView已经替代了ListView，局部刷新很有必要知道

收藏成功后mList.get(position).put("favorites", "0");ViewHolder viewHolder = (ViewHolder) mRecyclerView.findViewHolderForAdapterPosition(position);viewHolder.mCheck.setBackgroundResource(R.mipmap.collect_normal);