listView自动滑动功能

主要功能代码

package com.example.administrator.mytest;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.TextView;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Date;
import java.util.Timer;
import java.util.TimerTask;
public class Main2Activity extends AppCompatActivity {
    private ListView listView;
    private String[] a={"1","2","3","4","5","6","7","8","9"};
    private ArrayList<String> mData;
    public int index=-1;
    private TimerTask timerTask=new TimerTask() {
        @Override
        public void run() {
            Message msg=new Message();
            msg.what=1;
            handler.sendMessage(msg);
        }
    };
    private Handler handler=new Handler(){
        @Override
        public void handleMessage(Message msg) {
            switch (msg.what){
                case 1:
                    listViewScroll();
                    break;
            }
        }
    };
    private View listViewItem;
    private void listViewScroll() {
        listView.smoothScrollToPositionFromTop(index,-(listViewItem.getMeasuredHeight()+listView.getDividerHeight()),1000);
        index+=1;
        if (index>=listView.getCount()){
            Log.e("Main2Activity","listView.getCount():"+listView.getCount());
            index=0;
        }
    }
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);
        listView = (ListView)findViewById(R.id.lv);
        listView.setDividerHeight(0);
        listView.setDivider(null);
        mData = new ArrayList<String>(Arrays.asList(a));
        MyAdapter adapter = new MyAdapter();
        measureItem(adapter);
    }
    private void measureItem(MyAdapter adapter) {
        listView.setAdapter(adapter);
        listViewItem = adapter.getView(0, null, listView);
        listViewItem.measure(0,0);
        Log.e("Main2Activity","listViewItem :"+listViewItem.getMeasuredHeight());
        int totalHei = (listViewItem.getMeasuredHeight()+listView.getDividerHeight() ) * 4;
        listView.getLayoutParams().height=totalHei;
        new Timer().schedule(timerTask,new Date(),2000);
    }
    private class MyAdapter extends BaseAdapter{
        @Override
        public int getCount() {
            return Integer.MAX_VALUE;
        }
        @Override
        public int getItemViewType(int position) {
        if (position%2==0){
            return 0;
        }else{
            return 1;
        }
        }
        @Override
        public int getViewTypeCount() {
            return super.getViewTypeCount()+1;
        }
        @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) {
            ViewHolder holder;
            if (null==convertView){
                convertView=View.inflate(Main2Activity.this,R.layout.activity_main2_item,null);
                holder=new ViewHolder();
                holder.item=(TextView)convertView.findViewById(R.id.lv_item);
                holder.llItem=(LinearLayout)convertView.findViewById(R.id.ll_item);
                convertView.setTag(holder);
            }else{
                holder = (ViewHolder) convertView.getTag();
            }
            //不同条目设置背景色
            holder.llItem.setBackgroundResource(getItemViewType(position)==0?R.color.transparent:R.color.view_gray);
            holder.item.setText(mData.get(position%mData.size()));
            return convertView;
        }
    }
    static class ViewHolder{
        TextView item;
        LinearLayout llItem;
    }
    @Override
    protected void onDestroy() {
        timerTask.cancel();
        handler.removeCallbacksAndMessages(null);
        super.onDestroy();
    }
}