关于ListView的知识(3)

来源：互联网发布：源码分享是什么意思编辑：程序博客网时间：2024/04/30 11:58

ListView中getView中很冗余同时很多不好用的方法,我们需要复写BaseAdapter

-----他配合BaseHolder使用

-----该基类有为可以多提供一个item既Load_more

----- 暴露protected abstract BaseHolder<T> getItemHolder(int position);

让使用者根据postion使用不同的Item

------/**

* 如果孩子有item的点击事件，复写此方法即可

protected void onNoramlItemClick(AdapterView<?> parent, View view, int position, long id)

{

}

-----

使用--------------------------------------------------------------------------------

class HomeAdapter extends AppListAdapter

{

public HomeAdapter(AbsListView listView, List<AppInfoBean> datas) {

super(listView, datas);

// TODO Auto-generated constructor stub

}

@Override

protected List<AppInfoBean> onLoadMoreData() throws Exception

{

return loadMoreData(mDatas.size());

}

------------------------------------------------------------------------------------

======================================================

public class AppListAdapter extends SuperBaseAdapter<AppInfoBean> {

private List<AppInfoBean> mDatas;

public AppListAdapter(AbsListView listView, List<AppInfoBean> datas) {

super(listView, datas);

this.mDatas = datas;

}

@Override

protected BaseHolder<AppInfoBean> getItemHolder(int position) {

return new AppItemHolder();

}

/**

* adapter中每个 item的点击事件

@Override

protected void onNoramlItemClick(AdapterView<?> parent, View view,

int position, long id) {

// 跳转到应用详情页面

Context context = UIUtils.getContext();

Intent intent = new Intent(context, AppDetailActivity.class);

intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

intent.putExtra(AppDetailActivity.KEY_PACKAGENAME,

mDatas.get(position).packageName);

context.startActivity(intent);

}

-----------------------------------------------------------------------------------

=====================================================

public class AppItemHolder extends BaseHolder<AppInfoBean>

{

// T ---> item 对应的数据

// private TextView tv1;

// private TextView tv2;

@ViewInject(R.id.item_appinfo_iv_icon)

private ImageView mIvIcon;

@ViewInject(R.id.item_appinfo_rb_stars)

private RatingBar mRbStar;

@ViewInject(R.id.item_appinfo_tv_des)

private TextView mTvDes;

@ViewInject(R.id.item_appinfo_tv_size)

private TextView mTvSize;

@ViewInject(R.id.item_appinfo_tv_title)

private TextView mTvTitle;

@Override

protected View initView()

{

View view = View.inflate(UIUtils.getContext(), R.layout.item_app_info, null);

// 初始化View

// tv1 = (TextView) view.findViewById(R.id.tmp_tv_1);

// tv2 = (TextView) view.findViewById(R.id.tmp_tv_2);

// 注入

ViewUtils.inject(this, view);

return view;

}

@Override

protected void refreshUI(AppInfoBean data)

{

// 给View设置数据

// tv1.setText("头-" + data);

// tv2.setText("内容-" + data);

// 给View设置数据

mTvDes.setText(data.des);

mTvSize.setText(StringUtils.formatFileSize(data.size));

mTvTitle.setText(data.name);

mRbStar.setRating(data.stars);

mIvIcon.setImageResource(R.drawable.ic_default);// 设置默认值

// 需要去网络获取

String uri = Constans.IMAGE_BASE_URL + data.iconUrl;

BitmapHelper.display(mIvIcon, uri);

}

===================================================================

public class HomeFragment extends BaseFragment

{

private List<AppInfoBean> mDatas; // listView对应的数据

private List<String> mPictures; // 轮播图对应的数据

private HomeProtocol mProtocol;

@Override

protected View onLoadSuccessView()

{

// TextView tv = new TextView(UIUtils.getContext());

// tv.setText("首页");

// return tv;

ListView listView = ListViewFactory.getListView();

// 创建轮播的holder

HomePictureHolder holder = new HomePictureHolder();

// 给listView添加头

listView.addHeaderView(holder.getRootView());

// 给holder设置数据

holder.setData(mPictures);

// 设置数据 -->adapter ---> list

listView.setAdapter(new HomeAdapter(listView, mDatas));

return listView;

}

// 此方法实在子线程中执行的

@Override

protected LoadedResult onLoadingData()

{

// ## 1. 随机数的模拟

// LoadedResult[] results = new LoadedResult[] {

// LoadedResult.ERROR, LoadedResult.SUCCESS

// };

// Random rdm = new Random();

// try

// {

// Thread.sleep(1000);

// }

// catch (InterruptedException e)

// {

// // TODO Auto-generated catch block

// e.printStackTrace();

// }

// return results[rdm.nextInt(results.length)];

// // ## 2.模拟假数据

// mDatas = new ArrayList<String>();

// for (int i = 0; i < 50; i++)

// {

// mDatas.add(i + "");

// }

// return LoadedResult.SUCCESS;

// ## 3.去网络加载数据

// try

// {

// HttpUtils utils = new HttpUtils();

// // method,url,header,params

// String url = "http://10.0.2.2:8080/GooglePlayServer/home";

// RequestParams params = new RequestParams();

// params.addQueryStringParameter("index", 0 + "");

// ResponseStream stream = utils.sendSync(HttpMethod.GET, url, params);

// // 响应码

// int statusCode = stream.getStatusCode();

// if (200 == statusCode)

// {

// // 访问接口成功

// // 获取json字符

// String json = stream.readString();

// // 解析json字符

// Gson gson = new Gson();

// HomeBean bean = gson.fromJson(json, HomeBean.class);

// // 判断bean是否为空

// LoadedResult result = checkData(bean);

// if (result != LoadedResult.SUCCESS) { return result; }

// result = checkData(bean.list);

// if (result != LoadedResult.SUCCESS) { return result; }

// mDatas = bean.list;

// mPictures = bean.picture;

// return result;

// }

// else

// {

// // 访问接口失败

// return LoadedResult.ERROR;

// }

// catch (Exception e)

// {

// e.printStackTrace();

// // 联网失败

// return LoadedResult.ERROR;

// }

// ## 4.网络操作的简单抽取

mProtocol = new HomeProtocol();

try

{

HomeBean bean = mProtocol.loadData(0);

// 判断bean是否为空

LoadedResult result = checkData(bean);

if (result != LoadedResult.SUCCESS) { return result; }

result = checkData(bean.list);

if (result != LoadedResult.SUCCESS) { return result; }

mDatas = bean.list;

mPictures = bean.picture;

return result;

}

catch (Exception e)

{

e.printStackTrace();

return LoadedResult.ERROR;

}

class HomeAdapter extends AppListAdapter

{

public HomeAdapter(AbsListView listView, List<AppInfoBean> datas) {

super(listView, datas);

// TODO Auto-generated constructor stub

}

@Override

protected List<AppInfoBean> onLoadMoreData() throws Exception

{

return loadMoreData(mDatas.size());

}

private List<AppInfoBean> loadMoreData(int index) throws Exception

{

// HttpUtils utils = new HttpUtils();

// // method,url,header,params

// String url = "http://10.0.2.2:8080/GooglePlayServer/home";

// RequestParams params = new RequestParams();

// params.addQueryStringParameter("index", index + "");

// ResponseStream stream = utils.sendSync(HttpMethod.GET, url, params);

// // 响应码

// int statusCode = stream.getStatusCode();

// if (200 == statusCode)

// {

// // 访问接口成功

// // 获取json字符

// String json = stream.readString();

// // 解析json字符

// Gson gson = new Gson();

// HomeBean bean = gson.fromJson(json, HomeBean.class);

// if (bean == null) { return null; }

// return bean.list;

// }

// return null;

HomeBean bean = mProtocol.loadData(index);

if (bean == null) { return null; }

return bean.list;

}

1.SuperBaseAdapter

public abstract class SuperBaseAdapter<T> extends BaseAdapter implements OnItemClickListener

{

private final static int TYPE_LOAD_MORE = 0;

private final static int TYPE_NORMAL_ITEM = 1;

private List<T> mDatas;

private LoadMoreHolder mLoadMoreHolder;

private LoadMoreTask mLoadMoreTask;

private AbsListView mListView;

public SuperBaseAdapter(AbsListView listView, List<T> datas) {

this.mDatas = datas;

this.mListView = listView;

mListView.setOnItemClickListener(this);

}

@Override

public int getCount()

{

if (mDatas != null) { return mDatas.size() + 1; }// 添加加载更多的item

return 0;

}

@Override

public Object getItem(int position)

{

if (mDatas != null) { return mDatas.get(position); }

return null;

}

@Override

public long getItemId(int position)

{

return position;

}

// adapter对应的item view的类型个数

@Override

public int getViewTypeCount()

{

return super.getViewTypeCount() + 1;// 添加加载更多的样式

}

// 当前position是什么type类型,返回的类型必须从0开始，而且需要累加

@Override

public int getItemViewType(int position)

{

if ((getCount() - 1) == position)

{

// 加载更多

return TYPE_LOAD_MORE;

}

return getNormalItemViewType(position);

}

/**

* 父类默认额外的item就只有一种,如果孩子需要多种，那么复写此方法

* @param position

* @return

protected int getNormalItemViewType(int position)

{

return TYPE_NORMAL_ITEM;

}

@Override

public View getView(int position, View convertView, ViewGroup parent)

{

BaseHolder holder = null;

// ############### 1. 初始化item View #############################

if (convertView == null)

{

if (getItemViewType(position) == TYPE_LOAD_MORE)

{

// 加载更多的holder

holder = getLoadMoreHolder();

}

else

{

// 普通的holder

// 没有复用

// 1. 新建holder

holder = getItemHolder(position);// 太具体化

// 2. 加载视图

// convertView = View.inflate(UIUtils.getContext(),

// R.layout.item_tmp, null);// 太具体化

// 通过holder 来提供视图

}

convertView = holder.getRootView();

// // 3.设置标记

// convertView.setTag(holder);

// // 4. 给holder初始化view

// holder.tv1 = (TextView) convertView.findViewById(R.id.tmp_tv_1);

// holder.tv2 = (TextView) convertView.findViewById(R.id.tmp_tv_2);

}

else

{

// 有复用

holder = (BaseHolder) convertView.getTag();

}

// #########################################################

// ############ 2. 给View设置数据 #############################

// String data = mDatas.get(position);

// // 给holder中的view设置数据

// holder.tv1.setText("头-" + data);

// holder.tv2.setText("内容-" + data);

if (getItemViewType(position) == TYPE_LOAD_MORE)

{

// 给加载更多的holder添加数据

if (hasLoadMore())

{

// 有加载更多的功能

// 去网络加载数据，加载到 mDatas

performLoadMoreData();

}

else

{

// 没有加载更多

mLoadMoreHolder.setData(LoadMoreHolder.STATE_EMPTY);

}

else

{

// 给普通holder添加数据

T data = mDatas.get(position);

// 给holder中的view设置数据

holder.setData(data);

}

// #########################################################

return convertView;

}

private void performLoadMoreData()

{

// 去网络加载数据，加载到 mDatas

// 只允许一个加载更多的线程

if (mLoadMoreTask != null)

{

// 正在加载

return;

}

System.out.println("加载中......");

// 设置状态为加载更多

mLoadMoreHolder.setData(LoadMoreHolder.STATE_LOADING);

mLoadMoreTask = new LoadMoreTask();

ThreadManager.getLongPool().execute(mLoadMoreTask);

}

/**

* 默认adapter具备加载更多的功能，如果子类不希望有，就复写此方法

* @return

protected boolean hasLoadMore()

{

return true;

}

private LoadMoreHolder getLoadMoreHolder()

{

if (mLoadMoreHolder == null)

{

mLoadMoreHolder = new LoadMoreHolder();

}

return mLoadMoreHolder;

}

protected abstract BaseHolder<T> getItemHolder(int position);

/**

* 当加载更多时的回调,如果孩子有加载更多的功能，必须实现此方法

* @return

protected List<T> onLoadMoreData() throws Exception

{

return null;

}

class LoadMoreTask implements Runnable

{

@Override

public void run()

{

// 去网络加载数据，加载到 mDatas,UI更新

List<T> mMoreDatas = null;

int state = LoadMoreHolder.STATE_LOADING;

try

{

mMoreDatas = onLoadMoreData();

Thread.sleep(500);

// 如果数据为空--> 服务器已经没数据了

if (mMoreDatas == null || mMoreDatas.size() == 0)

{

state = LoadMoreHolder.STATE_EMPTY;

return;

}

int size = mMoreDatas.size();

// 如果数据不为空--> 小于一页的数据量，服务器已经没数据

if (size < Constans.PAGER_SIZE)

{

state = LoadMoreHolder.STATE_EMPTY;

}

else

{

// 如果数据不为空 -->等于一页的数据量，服务器有可能有更多的数据

state = LoadMoreHolder.STATE_LOADING;

}

catch (Exception e)

{

e.printStackTrace();

state = LoadMoreHolder.STATE_ERROR;

}

final int currentState = state;

final List<T> loadMoreDatas = mMoreDatas;

UIUtils.post(new Runnable() {

@Override

public void run()

{

// UI更新

// 更新加载更多

mLoadMoreHolder.setData(currentState);

if (currentState == LoadMoreHolder.STATE_ERROR)

{

// 如果产生异常

Toast.makeText(UIUtils.getContext(), "服务器异常", Toast.LENGTH_SHORT).show();

}

if (loadMoreDatas != null)

{

// 更新adapter

mDatas.addAll(loadMoreDatas);

// adapter更新

notifyDataSetChanged();

}

});

// 执行完成

mLoadMoreTask = null;

}

/**

* 如果孩子有item的点击事件，复写此方法即可

* @param parent

* @param view

* @param position

* @param id

protected void onNoramlItemClick(AdapterView<?> parent, View view, int position, long id)

{

}

@Override

public void onItemClick(AdapterView<?> parent, View view, int position, long id)

{

// position 指的是listView的position(含头)，不是adapter的position

if (mListView instanceof ListView)

{

int count = ((ListView) mListView).getHeaderViewsCount();

position = position - count;

}

if (getItemViewType(position) == TYPE_LOAD_MORE)

{

// 点击的是加载更多

int currentState = mLoadMoreHolder.getCurrentState();

if (currentState == LoadMoreHolder.STATE_ERROR)

{

// 去加载更多

performLoadMoreData();

}

else

{

// 点击的是普通的item

onNoramlItemClick(parent, view, position, id);

}

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