判断网络展示数据专项练习
protected View CreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment1, container, false);
MyHelper helper = new MyHelper(getActivity());
database = helper.getReadableDatabase();
//初始化控件
listView = view.findViewById(R.id.pullto);
//设置刷新模式
listView.setMode(PullToRefreshListView.Mode.BOTH);
//设置监听
listView.setOnRefreshListener(new PullToRefreshBase.OnRefreshListener2() {
@Override
public void onPullDownToRefresh(PullToRefreshBase refreshView) {
type = 1;
page = 1;
getVisible();
}
@Override
public void onPullUpToRefresh(PullToRefreshBase<ListView> refreshView) {
type = 2;
page++;
getVisible();
}
});
//判断网络状态
boolean hasNet = HttpUtils.hasNet(getActivity());
if (hasNet) {
getVisible();
} else {
cursor = database.query("test", null, null, null, null, null, null);
cursor.moveToNext();
String json = cursor.getString(cursor.getColumnIndex("content"));
//使用Gson
Gson gson = new Gson();
NewsBean newsBean = gson.fromJson(json, NewsBean.class);
List<NewsBean.DataBean> list = newsBean.getData();
//设置适配器
adapter3 = new MyAdapter3(getActivity(), list);
listView.setAdapter(adapter3);
}
return view;
}
// @Override
protected void getVisible() {
//获取工具类
HttpUtils httpUtils = HttpUtils.httpUtils();
//获取接口
httpUtils.get(HttpConfigs.news_url + "&page=" + page);
httpUtils.setOnHttpLoadListener(new HttpUtils.HttpLoadListener() {
@Override
public void loadSuccess(String json) {
//存入数据库
ContentValues values = new ContentValues();
values.put("content", json);
Log.d(TAG, "loadSuccess: " + json);
database.insert("test", null, values);
// database.close();
//使用Gson
Gson gson = new Gson();
NewsBean newsBean = gson.fromJson(json, NewsBean.class);
//判断
switch (type) {
case 0:
list = newsBean.getData();
adapter3 = new MyAdapter3(getActivity(), list);
listView.setAdapter(adapter3);
break;
case 1:
list = newsBean.getData();
adapter3 = new MyAdapter3(getActivity(), list);
listView.setAdapter(adapter3);
listView.onRefreshComplete();
break;
case 2:
List<NewsBean.DataBean> list2 = newsBean.getData();
list.addAll(list2);
adapter3.notifyDataSetChanged();
listView.onRefreshComplete();
break;
}
}
@Override
public void loadError(String error) {
}
});
}
Fragment基类的使用
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
return CreateView(inflater, container, savedInstanceState);
}
protected abstract View CreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState);
protected abstract void getVisible();
// @Override
// public void setUserVisibleHint(boolean isVisibleToUser) {
// super.setUserVisibleHint(isVisibleToUser);
// if (isVisibleToUser) {
// getVisible();
// }
// }