Android动态刷新listview中的数据
之前一直困扰listview刷新后位置的问题，现在才明白，原来不能重新设置listview的adapter，而应该用notifyDataSetChanged()来刷新，这样位置就不会置顶。 下面做了一个测试的例子，点击最后一条记录，会增加一条新的记录， 代码如下： 1.TestAdapter package com.TestAdapter; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; import android.app.Activity; import android.content.Context; import android.os.Bundle; import android.view.View; import android.view.ViewGroup; import android.widget.AdapterView; import android.widget.AbsListView.OnScrollListener; import android.widget.AdapterView.OnItemClickListener; import android.widget.AdapterView.OnItemSelectedListener; import android.widget.AbsListView; import android.widget.ImageView; import android.widget.ListView; import android.widget.SimpleAdapter; import android.widget.TextView; import android.widget.Toast; public class TestAdapter extends Activity { /** Called when the activity is first created. */ private int[] images ; private ListView listview; private MyAdapter adapter; List<Map<String,Integer>> al; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); images = new int[]{android.R.drawable.ic_btn_speak_now, android.R.drawable.alert_light_frame, android.R.drawable.arrow_down_float, android.R.drawable.arrow_up_float, android.R.drawable.btn_star_big_off, android.R.drawable.btn_star_big_on, android.R.drawable.button_onoff_indicator_off, android.R.drawable.button_onoff_indicator_on, android.R.drawable.checkbox_off_background, android.R.drawable.checkbox_on_background, android.R.drawable.ic_btn_speak_now, android.R.drawable.ic_delete}; listview = (ListView)findViewById(R.id.listview); al = new ArrayList<Map<String,Integer>>(); for(int i=0; i<12; i++){ HashMap<String,Integer > map = new HashMap<String,Integer>(); map.put(""+i, images[i]); al.add(map); } adapter = new MyAdapter(this, al, R.layout.list_item, new String[]{"imageview", "tv"}, new int[]{R.id.imageview, R.id.tv}); listview.setAdapter(adapter); listview.setOnItemClickListener(new OnItemClickListener() { public void onItemClick(AdapterView<?> arg0, View arg1, int count, long arg3) { if(adapter.getCount()==count+1){ HashMap<String ,Integer> map = new HashMap<String, Integer>(); map.put(""+(adapter.mItemList.size()), android.R.drawable.ic_dialog_email); al.add(map); adapter.mItemList = al; adapter.notifyDataSetChanged(); Toast.makeText(TestAdapter.this, "正在刷新", Toast.LENGTH_SHORT).show(); } } }); } private class MyAdapter extends SimpleAdapter{ int count = 0; private List<Map<String, Integer>> mItemList; public MyAdapter(Context context, List<? extends Map<String, Integer>> data, int resource, String[] from, int[] to) { super(context, data, resource, from, to); mItemList = (List<Map<String, Integer>>) data; if(data == null){ count = 0; }else{ count = data.size(); } } public int getCount() { return mItemList.size(); } public Object getItem(int pos) { return pos; } public long getItemId(int pos) { return pos; } @Override public View getView(int position, View convertView, ViewGroup parent) { Map<String ,Integer> map = mItemList.get(position); int image = map.get(""+position); View view = super.getView(position, convertView, parent); ImageView imageview = (ImageView)view.findViewById(R.id.imageview); TextView tv = (TextView)view.findViewById(R.id.tv); imageview.setBackgroundResource(image); tv.setText(""+position); return view; } } } 2.main.xml <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent" > <ListView android:id="@+id/listview" android:layout_width="fill_parent" android:layout_height="wrap_content" ></ListView> </LinearLayout> 3.list_item.xml <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent" > <ImageView android:id="@+id/imageview" android:layout_width="wrap_content" android:layout_height="wrap_content"> </ImageView> <TextView android:id="@+id/tv" android:layout_width="fill_parent" android:layout_height="wrap_content" ></TextView> </LinearLayout> 本文转自 wws5201985 51CTO博客，原文链接：http://blog.51cto.com/wws5201985/786470，如需转载请自行联系原作者
