Android开发之ListView实现Item局部刷新

 private void updateView(int itemIndex) {
 //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
 if (itemIndex - visiblePosition >= ) {
 //得到要更新的item的view
 View view = mListView.getChildAt(itemIndex - visiblePosition);
 //调用adapter更新界面
 mAdapter.updateView(view, itemIndex);
 }
 }

 @Override
 public void onReceive(Context context, Intent intent) {
 AppContent appContent = intent.getParcelableExtra("appContent");
 if(appContent == null) return;
 int itemIndex = ;
 for(AppContent appContent : mList) {
  if(appContent.getUrl().equals(appContent.getUrl())) {
  itemIndex = mList.indexOf(appContent);
  appContent.setDownloadPercent(appContent.getDownloadPercent());
  break;
  }
 }
 updateView(itemIndex);
 }

 public class AppContentAdapter extends BaseAdapter{
 private List<AppContent> mDates = null;
 private Context mContext;
 public AppContentAdapter(Context context) {
 this.mContext = context;
 }
 @Override
 public int getCount() {
 return mDates.size();
 }
 @Override
 public Object getItem(int position) {
 return mDates.get(position);
 }
 @Override
 public long getItemId(int position) {
 return position;
 }
 public void setDates(List<AppContent> mDates) {
 this.mDates = mDates;
 }
 @Override
 public View getView(int position, View convertView, ViewGroup parent) {
 ViewHolder holder = null;
 if (convertView == null) {
 holder = new ViewHolder();
 convertView = LayoutInflater.from(mContext).inflate(
  R.layout.listitem_download, null);
 holder.statusIcon = (DownloadPercentView) convertView.findViewById(R.id.status_icon);
 holder.name = (TextView) convertView.findViewById(R.id.name);
 holder.downloadPercent = (TextView) convertView.findViewById(R.id.download_percent);
 holder.progressBar = (ProgressBar) convertView.findViewById(R.id.progressbar);
 convertView.setTag(holder);
 } else {
 holder = (ViewHolder) convertView.getTag();
 }
 setData(holder, position);
 return convertView;
 }
 /**
 * 设置viewHolder的数据
 * @param holder
 * @param itemIndex
 */
 private void setData(ViewHolder holder, int itemIndex) {
 AppContent appContent = mDates.get(itemIndex);
 holder.name.setText(appContent.getName());
 holder.progressBar.setProgress(appContent.getDownloadPercent());
 setIconByStatus(holder.statusIcon, appContent.getStatus());
 if(appContent.getStatus() == AppContent.Status.PENDING) {
 holder.downloadPercent.setVisibility(View.INVISIBLE);
 } else {
 holder.downloadPercent.setVisibility(View.VISIBLE);
 holder.statusIcon.setProgress(appContent.getDownloadPercent());
 holder.downloadPercent.setText("下载进度：" + appContent.getDownloadPercent() + "%");
 }
 }
 /**
 * 局部刷新
 * @param view
 * @param itemIndex
 */
 public void updateView(View view, int itemIndex) {
 if(view == null) {
 return;
 }
 //从view中取得holder
 ViewHolder holder = (ViewHolder) view.getTag();
 holder.statusIcon = (DownloadPercentView) view.findViewById(R.id.status_icon);
 holder.name = (TextView) view.findViewById(R.id.name);
 holder.downloadPercent = (TextView) view.findViewById(R.id.download_percent);
 holder.progressBar = (ProgressBar) view.findViewById(R.id.progressbar);
 setData(holder, itemIndex);
 }
 /**
 * 根据状态设置图标
 * @param downloadPercentView
 * @param status
 */
 private void setIconByStatus(DownloadPercentView downloadPercentView, AppContent.Status status) {
 downloadPercentView.setVisibility(View.VISIBLE);
 if(status == AppContent.Status.PENDING) {
 downloadPercentView.setStatus(DownloadPercentView.STATUS_PEDDING);
 }
 if(status == AppContent.Status.DOWNLOADING) {
 downloadPercentView.setStatus(DownloadPercentView.STATUS_DOWNLOADING);
 }
 if(status == AppContent.Status.WAITING) {
 downloadPercentView.setStatus(DownloadPercentView.STATUS_WAITING);
 }
 if(status == AppContent.Status.PAUSED) {
 downloadPercentView.setStatus(DownloadPercentView.STATUS_PAUSED);
 }
 if(status == AppContent.Status.FINISHED) {
 downloadPercentView.setStatus(DownloadPercentView.STATUS_FINISHED);
 }
 }
 private class ViewHolder {
 private DownloadPercentView statusIcon;
 private TextView name;
 private TextView downloadPercent;
 private ProgressBar progressBar;
 }
 }