如何以编程方式在Android中滚动ListView到最多向下的手势
作者：互联网
我是android的新手,并在我的演示应用程序中实现了pull to refresh和自定义ListView.我正在从listItem类中删除一个项目,当我正在刷新该项目从我的ListView中删除但它必须要这样做,我想删除该项目一旦删除.我已经尝试了notifyDatasetChange,这将无法在我的所以我想以编程方式将我的列表拉下来,所以列表会刷新,请帮我做.感谢你
public class TimelineFragment extends BaseFragment implements LoaderManager.LoaderCallbacks<List<Post>>, OnRefreshListener, OnScrollListener {
private static boolean inBackground = false;
public static android.widget.PopupMenu popupMenu;
private int index = -1;
private int top = 0;
public static TimelineAdapter mTimelineAdapter;
public TimelineLoader mTimelineLoader;
public PullToRefreshLayout mPullToRefreshLayout;
public static ListView mListViewTimeline;
ProgressBar mProgressBarLoading;
TextView mTextViewNoItems;
ImageView im;
Menu mm;
int total;
Activity activity;
private int hot_number = 0;
private TextView ui_hot = null;
int lastPosition;
int lastTop;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
ViewGroup rootView = (ViewGroup) inflater.inflate(R.layout.fragment_timeline, container, false);
setHasOptionsMenu(true);
return rootView;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setHasOptionsMenu(true);
}
private boolean isAppIsInBackground(Context context) {
boolean isInBackground = true;
ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
List<ActivityManager.RunningTaskInfo> taskInfo = am.getRunningTasks(1);
ComponentName componentInfo = taskInfo.get(0).topActivity;
if (componentInfo.getPackageName().equals(context.getPackageName())) {
isInBackground = false;
}
return isInBackground;
}
public void updateHotCount(final int new_hot_number) {
hot_number = new_hot_number;
if (ui_hot == null) return;
if (new_hot_number == 0)
ui_hot.setVisibility(View.INVISIBLE);
else {
ui_hot.setVisibility(View.VISIBLE);
ui_hot.setText(Integer.toString(new_hot_number));
}
}
@Override
public void onPause() {
super.onPause();
if (isAppIsInBackground(getActivity())) {
Log.d("ACTION", "RETURN FROM BACGRKOUDN");
getLoaderManager().destroyLoader(0);
getLoaderManager().initLoader(0, null, TimelineFragment.this);
}
}
public void onStop() {
super.onStop();
if(mTimelineLoader != null) {
mTimelineLoader.stopLoading();
}
lastPosition = mListViewTimeline.getFirstVisiblePosition();
View v = mListViewTimeline.getChildAt(0);
lastTop = (v == null) ? 0 : v.getTop();
// lastPosition = mListViewTimeline.getSelectedItemPosition();
// int lastPositionInGroup = lastPosition - mListViewTimeline.getFirstVisiblePosition();
// lastTop = mListViewTimeline.getChildAt( lastPositionInGroup ).getTop();
}
@Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
super.onCreateOptionsMenu(menu, inflater);
getActivity().getMenuInflater().inflate(R.menu.search_post, menu);
final View menu_hotlist = menu.findItem(R.id.activity22).getActionView();
ui_hot = (TextView) menu_hotlist.findViewById(R.id.hotlist_hot);
SharedPreferences preferences = getActivity().getSharedPreferences("Notifications", Context.MODE_PRIVATE);
SharedPreferences.Editor editor = preferences.edit();
updateHotCount(preferences.getInt("notifications", 0));
new MyMenuItemStuffListener(menu_hotlist, "Show hot message") {
@Override
public void onClick(View v) {
Intent intent = new Intent(getActivity(), ActivityActivity.class);
intent.putExtra("View_mode", true);
startActivity(intent);
}
};
}
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == R.id.search22) {
// Log.d("MyApp", "action bar clicked");
Intent intent = new Intent(getActivity(), SearchPostActivity.class);
intent.putExtra("View_mode", true);
startActivity(intent);
}
if (id == R.id.activity22) {
Intent intent = new Intent(getActivity(), ActivityActivity.class);
intent.putExtra("View_mode", true);
startActivity(intent);
}
return super.onOptionsItemSelected(item);
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
total = 0;
mPullToRefreshLayout = (PullToRefreshLayout) getActivity().findViewById(R.id.ptr_layout);
ActionBarPullToRefresh.from(getActivity()).allChildrenArePullable().listener(this).setup(mPullToRefreshLayout);
mProgressBarLoading = (ProgressBar) getActivity().findViewById(R.id.progressBarLoading);
mTextViewNoItems = (TextView) getActivity().findViewById(R.id.textViewNoItems);
mTimelineAdapter = new TimelineAdapter(getActivity());
mListViewTimeline = (ListView) getActivity().findViewById(R.id.listViewTimeline);
mListViewTimeline.setEmptyView(mProgressBarLoading);
mListViewTimeline.setAdapter(mTimelineAdapter);
mTimelineAdapter.notifyDataSetChanged();
mListViewTimeline.setOnScrollListener(this);
// mListViewTimeline.setTranscriptMode(ListView.TRANSCRIPT_MODE_ALWAYS_SCROLL);
mListViewTimeline.setVerticalScrollBarEnabled(false);
activity = getActivity();
if(activity != null) {
final Handler handler = new Handler();
handler.postDelayed(new Runnable() {
@Override
public void run() {
getLoaderManager().initLoader(0, null, TimelineFragment.this);
//Do something after 100ms
}
}, 1000);
mTextViewNoItems.setOnClickListener(new OnClickListener() {
@Override
public void onClick(final View v) {
getLoaderManager().destroyLoader(0);
getLoaderManager().initLoader(0, null, TimelineFragment.this);
Log.d("CLICK", "REFRESH");
}
});
}
}
@Override
public Loader<List<Post>> onCreateLoader(int id, Bundle args) {
mTimelineLoader = new TimelineLoader(getActivity(), mListViewTimeline);
setHasOptionsMenu(true);
return mTimelineLoader;
}
@Override
public void onl oadFinished(Loader<List<Post>> arg0, List<Post> data) {
mTimelineAdapter.setData(data);
mTimelineAdapter.notifyDataSetChanged();
mPullToRefreshLayout.setRefreshComplete();
mTextViewNoItems.setVisibility(View.VISIBLE);
mProgressBarLoading.setVisibility(View.INVISIBLE);
mListViewTimeline.setEmptyView(mTextViewNoItems);
if (data.isEmpty()) {
getLoaderManager().destroyLoader(0);
getLoaderManager().initLoader(0, null, TimelineFragment.this);
}
}
@Override
public void onl oaderReset(Loader<List<Post>> arg0) {
mTimelineAdapter.setData(null);
setHasOptionsMenu(true);
}
@Override
public void onRefreshStarted(View view) {
getLoaderManager().destroyLoader(0);
getLoaderManager().initLoader(0, null, this);
mTextViewNoItems.setVisibility(View.INVISIBLE);
mProgressBarLoading.setVisibility(View.VISIBLE);
mListViewTimeline.setEmptyView(mProgressBarLoading);
}
@Override
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
if (firstVisibleItem + visibleItemCount >= totalItemCount && visibleItemCount != 0) {
if (mTimelineLoader.loadMore() && !mTimelineLoader.loading()) {
total = totalItemCount - 1;
lastPosition = view.getFirstVisiblePosition();
View v = view.getChildAt(0);
lastTop = (v == null) ? 0 : v.getTop();
mTimelineLoader.onContentChanged();
}
}
}
解决方法:
将以下代码添加到您的活动类以在另一个类中获取它的实例并刷新ListView：
private static MainActivity instance;
@Override
protected void onStart() {
super.onStart();
instance = this;
}
public static MainActivity getInstance(){
return instance;
}
public void refreshListView(){
mTimelineAdapter = new TimelineAdapter(getActivity());
mListViewTimeline.setAdapter(mTimelineAdapter);
mTimelineAdapter.notifyDataSetChanged();
}
您现在可以使用以下代码从要删除行的类中调用refreshListView()：
// call this after removal to refresh the List View
MainActivity.getInstance().refreshListView();
标签：android,listview,loader,pull-to-refresh 来源： https://codeday.me/bug/20190711/1431659.html