@Overrideprotected void onCreate(Bundle savedInstanceState){ super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); final ArrayList title = new ArrayList (); for (int i = 0; i < 20; i++) { title.add("标题" + i); } ListView listView = (ListView) findViewById(R.id.listView1); listView.setAdapter(new BaseAdapter() { @Override public View getView(int position, View convertView, ViewGroup parent)//执行数等于当前页面出现的行数,convertView指滚动消失的layout { Log.e("getView", "调用getView"+ i++ + "convertView:" + convertView); LayoutInflater inf = getLayoutInflater();//通过LayoutInflater将布局id转换到对象 RelativeLayout relativeLayout = (RelativeLayout) inf.inflate(R.layout.relat, null); TextView titleview = (TextView) relativeLayout.findViewById(R.id.textView1);//通过布局找到里面的控件 titleview.setText(title.get(position));//得到容器内的内容 return relativeLayout; } @Override public long getItemId(int position) { return 0; } @Override public Object getItem(int position) { return null; } @Override //先执行getCount再执行getView，出现新行数时再次执行getCount //listview清单里要设置高度match_parent //每次点击屏幕一次都会先执行getCount public int getCount() { Log.e("getCount", "调用getCount"+ j++); return title.size(); } });} 复用converview：
ListView listView = (ListView) findViewById(R.id.listView1);listView.setAdapter(new BaseAdapter(){ @Override public View getView(int position, View convertView, ViewGroup parent)//执行数等于当前页面出现的行数,convertView指滚动消失的layout { //复用converview RelativeLayout relativeLayout = null; if(convertView == null) { LayoutInflater inf = getLayoutInflater(); relativeLayout = (RelativeLayout) inf.inflate(R.layout.relat, null); } else { relativeLayout = (RelativeLayout) convertView; } TextView titleView = (TextView) relativeLayout.findViewById(R.id.textView1); titleView.setText(title.get(position)); return relativeLayout; } 继续优化：
public class MainActivity extends Activity{ int imID = 0; class Msg//内容 { String mTitle; String mSubtitle; String mTime; int mImagID; public Msg(String mTitle, String mSubtitle, String mTime, int mImagID) { super(); this.mTitle = mTitle; this.mSubtitle = mSubtitle; this.mTime = mTime; this.mImagID = mImagID; } } class ViewHolder//控件 { TextView viewTitle; TextView viewSubtitle; TextView viewTime; ImageView viewImage; } @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); Date timeNow = new Date(); SimpleDateFormat timeFormat = new SimpleDateFormat("HH:mm:ss"); String time = timeFormat.format(timeNow); final ArrayList msgList = new ArrayList (); for (int i = 0; i < 30; i++)//选择图片 { if(i % 4 == 0) { imID = R.drawable.ic_launcher; } if(i % 4 == 1) { imID = R.drawable.ic_1; } if(i % 4 == 2) { imID = R.drawable.ic_2; } if(i % 4 == 3) { imID = R.drawable.ic_3; } Msg msg = new Msg("标题" + i, "内容" + i, time ,imID); msgList.add(msg); } ListView listView = (ListView) findViewById(R.id.listView1); listView.setAdapter(new BaseAdapter() { ViewHolder holder = null; @Override public View getView(int position, View convertView, ViewGroup parent) { RelativeLayout relout = null; if (convertView == null)//创建首页时才find控件 { LayoutInflater layoutInflater =getLayoutInflater(); relout = (RelativeLayout) layoutInflater.inflate(R.layout.relaout, null); holder = new ViewHolder(); holder.viewTitle= (TextView) relout.findViewById(R.id.textView_title); holder.viewSubtitle = (TextView) relout.findViewById(R.id.textView_subtitle); holder.viewTime = (TextView) relout.findViewById(R.id.textView_time); holder.viewImage = (ImageView) relout.findViewById(R.id.p_w_picpathView1); relout.setTag(holder); } else//否则复用layout和view { relout = (RelativeLayout) convertView; holder = (ViewHolder) relout.getTag();//记得得到holder } Msg msg = msgList.get(position); holder.viewTitle.setText(msg.mTitle); holder.viewSubtitle.setText(msg.mSubtitle); holder.viewTime.setText(msg.mTime); holder.viewImage.setImageResource(msg.mImagID);//设置图片的方法 return relout; } @Override public long getItemId(int position) { return 0; } @Override public Object getItem(int position) { return null; } @Override public int getCount() { return msgList.size(); } }); } @Override public boolean onCreateOptionsMenu(Menu menu) { getMenuInflater().inflate(R.menu.activity_main, menu); return true; } } 点击按钮更新listview：Adapter使用notifyDataSetChanged()通知listview更新
3private void btn1Click()//增加一行信息{ i++; data.add("内容" + i ); arrAdapter.notifyDataSetChanged();//Adapter通知listview做更新}private void btn2Click()//删除第一行信息{ if(data.size() < 1) { Toast.makeText(this, "信息已删除完毕！", Toast.LENGTH_LONG).show(); } else { data.remove(0); arrAdapter.notifyDataSetChanged();//Adapter通知listview做更新 }}private void btnsortClick()//对列表进行排序{ Collections.sort(data); arrAdapter.notifyDataSetChanged();} 注：
1.LayoutInflater inflater = getLayoutInflater();
layout = (RelativeLayout) inflater.inflate(R.layout.relayout, null);
layout要通过LayoutInflater拿到。
2.getView返回layout，getCount()返回int。
3.layout.getTag()要转换为holder = (ViewHolder)。