未注释的参数覆盖 @NonNull 参数
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【中文标题】未注释的参数覆盖 @NonNull 参数【英文标题】：Not annotated parameter overrides @NonNull parameter 【发布时间】：2019-09-24 19:52:04 【问题描述】：inflater 出现@nonnull 错误，任何人都可以解决此错误吗？ 我是android新手我不知道如何解决这个错误任何解决方案？ 是主题的错误还是其他什么，我的代码有什么大问题吗？你能解决这个错误吗？由于此错误，我的代码无法正常工作。非常感谢您的帮助
下面列出了我在代码中的导入
import android.content.Context;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.app.DownloadManager;
import android.net.Uri;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Environment;
import android.os.Handler;
import android.os.Message;
import android.support.annotation.Nullable;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.support.v7.widget.DividerItemDecoration;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageButton;
import android.widget.ProgressBar;
import android.widget.TextView;
import android.widget.Toast;
import java.util.List;
import android.support.annotation.Nullable;
import android.util.Log;
import com.google.gson.Gson;
import com.google.gson.reflect.TypeToken;
import android.widget.ImageButton;
import android.widget.ProgressBar;
import static android.content.Context.DOWNLOAD_SERVICE;
import java.lang.reflect.Type;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.io.StringWriter;
import java.io.Writer;
import java.lang.ref.WeakReference;
import java.lang.reflect.Type;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
public class FilesListingFragment extends android.support.v4.app.Fragment
private static final String TAG = "FilesListingFragment";
public static final String PATH_FILES = "http://%s:%s/files";
public static final String PATH_STATUS = "http://%s:%s/status";
public static final String PATH_FILE_DOWNLOAD = "http://%s:%s/file/%s";
private String mSenderIp = null, mSenderSSID;
private ContactSenderAPITask mUrlsTask;
private ContactSenderAPITask mStatusCheckTask;
private String mPort, mSenderName;
static final int CHECK_SENDER_STATUS = 100;
static final int SENDER_DATA_FETCH = 101;
RecyclerView file;
ProgressBar progressBar;
TextView mTextView;
private SenderFilesListingAdapter mFilesAdapter;
private UiUpdateHandler uiUpdateHandler;
private static final int SENDER_DATA_FETCH_RETRY_LIMIT = 3;
private int senderDownloadsFetchRetry = SENDER_DATA_FETCH_RETRY_LIMIT, senderStatusCheckRetryLimit = SENDER_DATA_FETCH_RETRY_LIMIT;
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState)
View v = inflater.inflate(R.layout.fragment_files_listing, null);
file = (RecyclerView) v.findViewById(R.id.files_list);
progressBar = (ProgressBar) v.findViewById(R.id.loading);
mTextView = (TextView) v.findViewById(R.id.empty_listing_text);
mTextView.setOnClickListener(new View.OnClickListener()
@Override
public void onClick(View view)
mTextView.setVisibility(View.GONE);
progressBar.setVisibility(View.VISIBLE);
fetchSenderFiles();
);
file.setLayoutManager(new LinearLayoutManager(getActivity()));
file.addItemDecoration(new DividerItemDecoration(getResources().getDrawable(R.drawable.lidivider)));/**here is the error */
mFilesAdapter = new SenderFilesListingAdapter(new ArrayList<String>());
file.setAdapter(mFilesAdapter);
uiUpdateHandler = new UiUpdateHandler(this);
return v;
public static FilesListingFragment getInstance(String senderIp, String ssid, String senderName, String port)
FilesListingFragment fragment = new FilesListingFragment();
Bundle data = new Bundle();
data.putString("senderIp", senderIp);
data.putString("ssid", ssid);
data.putString("name", senderName);
data.putString("port", port);
fragment.setArguments(data);
return fragment;
@Override
public void onAttach(Context activity)
super.onAttach(activity);
if (null != getArguments())
mSenderIp = getArguments().getString("senderIp");
mSenderSSID = getArguments().getString("ssid");
mPort = getArguments().getString("port");
mSenderName = getArguments().getString("name");
Log.d(TAG, "sender ip: " + mSenderIp);
@Override
public void onResume()
super.onResume();
fetchSenderFiles();
checkSenderAPIAvailablity();
private void fetchSenderFiles()
progressBar.setVisibility(View.VISIBLE);
if (null != mUrlsTask)
mUrlsTask.cancel(true);
mUrlsTask = new ContactSenderAPITask(SENDER_DATA_FETCH);
mUrlsTask.execute(String.format(PATH_FILES, mSenderIp, mPort));
private void checkSenderAPIAvailablity()
if (null != mStatusCheckTask)
mStatusCheckTask.cancel(true);
mStatusCheckTask = new ContactSenderAPITask(CHECK_SENDER_STATUS);
mStatusCheckTask.execute(String.format(PATH_STATUS, mSenderIp, mPort));
@Override
public void onPause()
super.onPause();
if (null != mUrlsTask)
mUrlsTask.cancel(true);
@Override
public void onDestroy()
super.onDestroy();
if (null != uiUpdateHandler)
uiUpdateHandler.removeCallbacksAndMessages(null);
if (null != mStatusCheckTask)
mStatusCheckTask.cancel(true);
public String getSenderSSID()
return mSenderSSID;
public String getSenderIp()
return mSenderIp;
private void loadListing(String contentAsString)
Type collectionType = new TypeToken<List<String>>()
.getType();
ArrayList<String> files = new Gson().fromJson(contentAsString, collectionType);
progressBar.setVisibility(View.GONE);
if (null == files || files.size() == 0)
mTextView.setText("No Downloads found.\n Tap to Retry");
mTextView.setVisibility(View.VISIBLE);
else
mTextView.setVisibility(View.GONE);
mFilesAdapter.updateData(files);
private void onDataFetchError()
progressBar.setVisibility(View.GONE);
mTextView.setVisibility(View.VISIBLE);
mTextView.setText("Error occurred while fetching data.\n Tap to Retry");
private long postDownloadRequestToDM(Uri uri, String fileName)
// Create request for android download manager
DownloadManager downloadManager = (DownloadManager) getActivity().getSystemService(DOWNLOAD_SERVICE);
DownloadManager.Request request = new DownloadManager.Request(uri);
request.setTitle(fileName);
request.setDescription("ShareThem");
request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
request.setDestinationInExternalFilesDir(getActivity(),
Environment.DIRECTORY_DOWNLOADS, fileName);
return downloadManager.enqueue(request);
private class SenderFilesListingAdapter extends RecyclerViewArrayAdapter<String, SenderFilesListItemHolder>
SenderFilesListingAdapter(List<String> objects)
super(objects);
void updateData(List<String> objects)
clear();
mObjects = objects;
notifyDataSetChanged();
@Override
public SenderFilesListItemHolder onCreateViewHolder(ViewGroup parent, int viewType)
View itemView = LayoutInflater.from(parent.getContext()).
inflate(R.layout.listitem_file, parent, false);
return new SenderFilesListItemHolder(itemView);
@Override
public void onBindViewHolder(SenderFilesListItemHolder holder, int position)
final String senderFile = mObjects.get(position);
holder.itemView.setTag(senderFile);
final String fileName = senderFile.substring(senderFile.lastIndexOf('/') + 1, senderFile.length());
holder.title.setText(fileName);
holder.download.setOnClickListener(new View.OnClickListener()
@Override
public void onClick(View view)
postDownloadRequestToDM(Uri.parse(String.format(PATH_FILE_DOWNLOAD, mSenderIp, mPort, mObjects.indexOf(senderFile))), fileName);
Toast.makeText(getActivity(), "Downloading " + fileName + "...", Toast.LENGTH_SHORT).show();
);
static class SenderFilesListItemHolder extends RecyclerView.ViewHolder
TextView title;
ImageButton download;
SenderFilesListItemHolder(View itemView)
super(itemView);
title = (TextView) itemView.findViewById(R.id.sender_list_item_name);
download = (ImageButton) itemView.findViewById(R.id.sender_list_start_download);
/**
* Performs network calls to fetch data/status from Sender.
* Retries on error for times bases on values of @link FilesListingFragment#senderDownloadsFetchRetry
*/
private class ContactSenderAPITask extends AsyncTask<String, Void, String>
int mode;
boolean error;
ContactSenderAPITask(int mode)
this.mode = mode;
@Override
protected String doInBackground(String... urls)
error = false;
try
return downloadDataFromSender(urls[0]);
catch (IOException e)
e.printStackTrace();
error = true;
Log.e(TAG, "Exception: " + e.getMessage());
return null;
// onPostExecute displays the results of the AsyncTask.
@Override
protected void onPostExecute(String result)
switch (mode)
case SENDER_DATA_FETCH:
if (error)
if (senderDownloadsFetchRetry >= 0)
--senderDownloadsFetchRetry;
if (getView() == null || getActivity() == null || null == uiUpdateHandler)
return;
uiUpdateHandler.removeMessages(SENDER_DATA_FETCH);
uiUpdateHandler.sendMessageDelayed(uiUpdateHandler.obtainMessage(mode), 800);
return;
else senderDownloadsFetchRetry = SENDER_DATA_FETCH_RETRY_LIMIT;
if (null != getView())
onDataFetchError();
else if (null != getView())
loadListing(result);
else Log.e(TAG, "fragment may have been removed, File fetch");
break;
case CHECK_SENDER_STATUS:
if (error)
if (senderStatusCheckRetryLimit > 1)
--senderStatusCheckRetryLimit;
uiUpdateHandler.removeMessages(CHECK_SENDER_STATUS);
uiUpdateHandler.sendMessageDelayed(uiUpdateHandler.obtainMessage(CHECK_SENDER_STATUS), 800);
else if (getActivity() instanceof ReceiverActivity)
senderStatusCheckRetryLimit = SENDER_DATA_FETCH_RETRY_LIMIT;
((ReceiverActivity) getActivity()).resetSenderSearch();
Toast.makeText(getActivity(), getString(R.string.p2p_receiver_error_sender_disconnected), Toast.LENGTH_SHORT).show();
else
Log.e(TAG, "Activity is not instance of ReceiverActivity");
else if (null != getView())
senderStatusCheckRetryLimit = SENDER_DATA_FETCH_RETRY_LIMIT;
uiUpdateHandler.removeMessages(CHECK_SENDER_STATUS);
uiUpdateHandler.sendMessageDelayed(uiUpdateHandler.obtainMessage(CHECK_SENDER_STATUS), 1000);
else
Log.e(TAG, "fragment may have been removed: Sender api check");
break;
private String downloadDataFromSender(String apiUrl) throws IOException
InputStream is = null;
try
URL url = new URL(apiUrl);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setReadTimeout(10000 /* milliseconds */);
conn.setConnectTimeout(15000 /* milliseconds */);
conn.setRequestMethod("GET");
conn.setDoInput(true);
// Starts the query
conn.connect();
int response =
conn.getResponseCode();
Log.d(TAG, "The response is: " + response);
is = conn.getInputStream();
// Convert the InputStream into a string
return readIt(is);
finally
if (is != null)
is.close();
private String readIt(InputStream stream) throws IOException
Writer writer = new StringWriter();
char[] buffer = new char[1024];
try
Reader reader = new BufferedReader(
new InputStreamReader(stream, "UTF-8"));
int n;
while ((n = reader.read(buffer)) != -1)
writer.write(buffer, 0, n);
finally
stream.close();
return writer.toString();
private static class UiUpdateHandler extends Handler
WeakReference<FilesListingFragment> mFragment;
UiUpdateHandler(FilesListingFragment fragment)
mFragment = new WeakReference<>(fragment);
@Override
public void handleMessage(Message msg)
FilesListingFragment fragment = mFragment.get();
if (null == mFragment)
return;
switch (msg.what)
case CHECK_SENDER_STATUS:
fragment.checkSenderAPIAvailablity();
break;
case SENDER_DATA_FETCH:
fragment.fetchSenderFiles();
break;
fragment_files_listing
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_
android:layout_
xmlns:tools="http://schemas.android.com/tools"
android:orientation="vertical"
tools:context=".receiver.FilesListingFragment"
>
<android.support.v7.widget.RecyclerView
android:id="@+id/files_list"
android:layout_
android:layout_
android:scrollbars="vertical" />
<ProgressBar xmlns:android="http://schemas.android.com/apk/res/android"
style="@android:style/Widget.Holo.ProgressBar"
android:layout_
android:id="@+id/loading"
android:layout_
android:layout_centerInParent="true"
android:layout_gravity="center" />
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/empty_listing_text"
android:layout_
android:layout_
android:layout_centerInParent="true"
android:clickable="true"
android:gravity="center"
android:text="No Downloads found.\n Tap to Retry"
android:visibility="gone" />
</RelativeLayout>
【问题讨论】：
在哪一行显示错误？ 请分享您的日志和R.layout.fragment_files_listing xml 文件
@ferran 看看 xml
在这一行错误显示 public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState)
我认为由于这个错误还有一个看一下link
【参考方案1】：
未注解的参数覆盖@NonNull 参数
这只是一个警告。你有
@Override
public View onCreateView(LayoutInflater inflater...
而您要扩展的基类在 inflater 参数上有无效注释。
public View onCreateView(@NonNull LayoutInflater inflater...
您只需在 Android Studio 中按 alt-enter 即可获得一个快速修复菜单，该菜单可以选择在此处添加缺少的注释。
由于这个错误，我的代码无法正常工作。
缺少这样的注释只会导致警告。 “不工作”的原因是另一回事。请首先更新您的问题并在此处指定“不工作”对您意味着什么。
【讨论】：
可能由于这个错误，我的代码无法正常工作看看link【参考方案2】：尝试改变这一行
View v = inflater.inflate(R.layout.fragment_files_listing, null);
到
View v = inflater.inflate(R.layout.fragment_files_listing, container, false);
这将使用您的片段容器膨胀您的布局。
【讨论】：
可能是由于这个错误，我的代码不起作用看看link【参考方案3】：你必须改变这一行
View v = inflater.inflate(R.layout.fragment_files_listing, null);
到
View v = inflater.inflate(R.layout.fragment_files_listing, container, false);
然后清理你的项目并使缓存无效重启你的android工作室希望它会工作。
谢谢。
【讨论】：
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