好的，所以我最近正在为自己的个人偏好开发一个小项目，并且我实施了一些不起作用的代码。所以，正如大多数人所做的那样，我删除了它。但后来，我遇到了代码先验造成的同样的故障，但是当我检查时，它不在那里！我可能只是愚蠢，盲目，或者两者兼而有之，但我一直只在RecyclerView中获得一张卡片才能出现！如果你能找到答案，请随意给我打个电话，我非常感谢你。
P.S。是的，我对Java很新，所以在你决定烤我之前请记住这一点。
我的主要活动：
package com.example.whateverthefuckyouwant;
//Imports, in case you couldn't tell
import android.net.Uri;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.helper.ItemTouchHelper;
import android.util.Log;
import android.widget.TextView;
import android.widget.Toast;
import com.google.android.gms.common.api.GoogleApiClient;
import java.lang.reflect.Array;
import java.util.ArrayList;
import java.util.Arrays;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.GoogleApiAvailability;
import com.google.api.client.extensions.android.http.AndroidHttp;
import com.google.api.client.googleapis.extensions.android.gms.auth.GoogleAccountCredential;
import com.google.api.client.googleapis.extensions.android.gms.auth.GooglePlayServicesAvailabilityIOException;
import com.google.api.client.googleapis.extensions.android.gms.auth.UserRecoverableAuthIOException;
import com.google.api.client.http.HttpTransport;
import com.google.api.client.json.JsonFactory;
import com.google.api.client.json.jackson2.JacksonFactory;
import com.google.api.client.util.ExponentialBackOff;
import com.google.api.services.sheets.v4.SheetsScopes;
import com.google.api.services.sheets.v4.model.*;
import android.Manifest;
import android.accounts.AccountManager;
import android.app.Activity;
import android.app.Dialog;
import android.app.ProgressDialog;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.text.TextUtils;
import android.text.method.ScrollingMovementMethod;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.TextView;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.Random;
import pub.devrel.easypermissions.AfterPermissionGranted;
import pub.devrel.easypermissions.EasyPermissions;
public class MainActivity extends AppCompatActivity implements EasyPermissions.PermissionCallbacks {
GoogleAccountCredential mCredential;
ProgressDialog mProgress;
static final int REQUEST_ACCOUNT_PICKER = 1000;
static final int REQUEST_AUTHORIZATION = 1001;
static final int REQUEST_GOOGLE_PLAY_SERVICES = 1002;
static final int REQUEST_PERMISSION_GET_ACCOUNTS = 1003;
private static final String PREF_ACCOUNT_NAME = "accountName";
private static final String[] SCOPES = {SheetsScopes.SPREADSHEETS_READONLY };
private RecyclerView mRecyclerView;
private RecyclerView.Adapter mAdapter;
private RecyclerView.LayoutManager mLayoutManager;
//ArrayList holding data from the Google Sheets API
ArrayList<Team> teamAF;
//Number of cards that the user has cycled through
int cardNumber = 1;
//Integers for direction of swipe. 8 = Right, 4 = Left
int RIGHT = 8;
int LEFT = 4;
boolean first = true;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Initialize credentials and service object.
mCredential = GoogleAccountCredential.usingOAuth2(
getApplicationContext(), Arrays.asList(SCOPES))
.setBackOff(new ExponentialBackOff());
//Create Recycler View
mRecyclerView = (RecyclerView) findViewById(R.id.my_recycler_view);
//Specific size of Cards
mRecyclerView.setHasFixedSize(true);
//Design choices using LinearLayoutManager
mLayoutManager = new LinearLayoutManager(this);
mRecyclerView.setLayoutManager(mLayoutManager);
//Create teamAF array list
teamAF = new ArrayList<>();
//Ads another card, so as to make an infinite number of cards
teamAF.add(new Team());
//Creating and setting mAdapter with teamAF
mAdapter = new MyAdapter(teamAF);
mRecyclerView.setAdapter(mAdapter);
//Swipe code for cardView
ItemTouchHelper.SimpleCallback simpleItemTouchCallback = new ItemTouchHelper.SimpleCallback(0, ItemTouchHelper.LEFT | ItemTouchHelper.RIGHT) {
//Don't know what onMove does
@Override
public boolean onMove(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, RecyclerView.ViewHolder target) {
Toast.makeText(MainActivity.this, "on Move", Toast.LENGTH_SHORT).show();
return false;
}
// Direction 4 = left, Direction 8 = right
@Override
public void onSwiped(RecyclerView.ViewHolder viewHolder, int swipeDir) {
//Prints swipeDir integer into console
Log.e(".", swipeDir + "");
//Sets variables to null, so they can be reset later
Team t = null;
//String s is reset to a string of code that enables it to check the string in the API with your answer.
String s = "";
//Code for answer. swipeDir == Left(4); Right(8).
if (swipeDir == LEFT) {
//Sets s
s = ((TextView) viewHolder.itemView.findViewById(R.id.left)).getText().toString();
} else if (swipeDir == RIGHT) {
//checks the answer swiped with he API
s = ((TextView) viewHolder.itemView.findViewById(R.id.right)).getText().toString();
}
//Removes card from array
t = teamAF.remove(mRecyclerView.getChildAdapterPosition(viewHolder.itemView));
//Adds some nice animation effect
mAdapter.notifyItemRemoved(mRecyclerView.getChildAdapterPosition(viewHolder.itemView));
//Sends a toast message saying "correct" or "incorrect"
if(t.checkAnswer(s)) {
Toast.makeText(MainActivity.this, "Correct!", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(MainActivity.this, "Incorrect!", Toast.LENGTH_SHORT).show();
}
if(first) {
//This make the recyclerView shuffle
Collections.shuffle(teamAF, new Random());
first = false;
}
//Adding one, so the cards can go on forever
cardNumber++;
//Calls the methods
mAdapter = new MyAdapter(teamAF);
mRecyclerView.setAdapter(mAdapter);
//This is a 'benchmark' type 'achievement'
if (cardNumber == 50) {
Toast.makeText(getApplicationContext(), "You Reached 50 Points Without Losing! You're Doing Great!", Toast.LENGTH_SHORT).show();
} else if (cardNumber == 100) {
Toast.makeText(getApplicationContext(), "You Reached 100 Points Without Losing! You're A Genius!", Toast.LENGTH_SHORT).show();
}
}
};
//Allows the swiping inside the recyclerView
ItemTouchHelper itemTouchHelper = new ItemTouchHelper(simpleItemTouchCallback);
itemTouchHelper.attachToRecyclerView(mRecyclerView);
//Calls the google API
mProgress = new ProgressDialog(this);
mProgress.setMessage("Loading...");
getResultsFromApi();
}
//The green was commented from the site
/**
* Attempt to call the API, after verifying that all the preconditions are
* satisfied. The preconditions are: Google Play Services installed, an
* account was selected and the device currently has online access. If any
* of the preconditions are not satisfied, the app will prompt the user as
* appropriate.
*/
private void getResultsFromApi() {
if (! isGooglePlayServicesAvailable()) {
acquireGooglePlayServices();
} else if (mCredential.getSelectedAccountName() == null) {
chooseAccount();
} else if (! isDeviceOnline()) {
System.out.println("No network connection available.");
} else {
new MakeRequestTask(mCredential).execute();
}
}
/**
* Attempts to set the account used with the API credentials. If an account
* name was previously saved it will use that one; otherwise an account
* picker dialog will be shown to the user. Note that the setting the
* account to use with the credentials object requires the app to have the
* GET_ACCOUNTS permission, which is requested here if it is not already
* present. The AfterPermissionGranted annotation indicates that this
* function will be rerun automatically whenever the GET_ACCOUNTS permission
* is granted.
*/
@AfterPermissionGranted(REQUEST_PERMISSION_GET_ACCOUNTS)
private void chooseAccount() {
if (EasyPermissions.hasPermissions(
this, Manifest.permission.GET_ACCOUNTS)) {
String accountName = getPreferences(Context.MODE_PRIVATE)
.getString(PREF_ACCOUNT_NAME, null);
if (accountName != null) {
mCredential.setSelectedAccountName(accountName);
getResultsFromApi();
} else {
// Start a dialog from which the user can choose an account
startActivityForResult(
mCredential.newChooseAccountIntent(),
REQUEST_ACCOUNT_PICKER);
}
} else {
// Request the GET_ACCOUNTS permission via a user dialog
EasyPermissions.requestPermissions(
this,
"This app needs to access your Google account (via Contacts).",
REQUEST_PERMISSION_GET_ACCOUNTS,
Manifest.permission.GET_ACCOUNTS);
}
}
/**
* Called when an activity launched here (specifically, AccountPicker
* and authorization) exits, giving you the requestCode you started it with,
* the resultCode it returned, and any additional data from it.
* @param requestCode code indicating which activity result is incoming.
* @param resultCode code indicating the result of the incoming
* activity result.
* @param data Intent (containing result data) returned by incoming
* activity result.
*/
@Override
protected void onActivityResult(
int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
switch(requestCode) {
case REQUEST_GOOGLE_PLAY_SERVICES:
if (resultCode != RESULT_OK) {
} else {
getResultsFromApi();
}
break;
case REQUEST_ACCOUNT_PICKER:
if (resultCode == RESULT_OK && data != null &&
data.getExtras() != null) {
String accountName =
data.getStringExtra(AccountManager.KEY_ACCOUNT_NAME);
if (accountName != null) {
SharedPreferences settings =
getPreferences(Context.MODE_PRIVATE);
SharedPreferences.Editor editor = settings.edit();
editor.putString(PREF_ACCOUNT_NAME, accountName);
editor.apply();
mCredential.setSelectedAccountName(accountName);
getResultsFromApi();
}
}
break;
case REQUEST_AUTHORIZATION:
if (resultCode == RESULT_OK) {
getResultsFromApi();
}
break;
}
}
/**
* Respond to requests for permissions at runtime for API 23 and above.
* @param requestCode The request code passed in
* requestPermissions(android.app.Activity, String, int, String[])
* @param permissions The requested permissions. Never null.
* @param grantResults The grant results for the corresponding permissions
* which is either PERMISSION_GRANTED or PERMISSION_DENIED. Never null.
*/
@Override
public void onRequestPermissionsResult(int requestCode,
@NonNull String[] permissions,
@NonNull int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
EasyPermissions.onRequestPermissionsResult(
requestCode, permissions, grantResults, this);
}
/**
* Callback for when a permission is granted using the EasyPermissions
* library.
* @param requestCode The request code associated with the requested
* permission
* @param list The requested permission list. Never null.
*/
@Override
public void onPermissionsGranted(int requestCode, List<String> list) {
// Do nothing.
}
/**
* Callback for when a permission is denied using the EasyPermissions
* library.
* @param requestCode The request code associated with the requested
* permission
* @param list The requested permission list. Never null.
*/
@Override
public void onPermissionsDenied(int requestCode, List<String> list) {
// Do nothing.
}
/**
* Checks whether the device currently has a network connection.
* @return true if the device has a network connection, false otherwise.
*/
private boolean isDeviceOnline() {
ConnectivityManager connMgr =
(ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo networkInfo = connMgr.getActiveNetworkInfo();
return (networkInfo != null && networkInfo.isConnected());
}
/**
* Check that Google Play services APK is installed and up to date.
* @return true if Google Play Services is available and up to
* date on this device; false otherwise.
*/
private boolean isGooglePlayServicesAvailable() {
GoogleApiAvailability apiAvailability =
GoogleApiAvailability.getInstance();
final int connectionStatusCode =
apiAvailability.isGooglePlayServicesAvailable(this);
return connectionStatusCode == ConnectionResult.SUCCESS;
}
/**
* Attempt to resolve a missing, out-of-date, invalid or disabled Google
* Play Services installation via a user dialog, if possible.
*/
private void acquireGooglePlayServices() {
GoogleApiAvailability apiAvailability =
GoogleApiAvailability.getInstance();
final int connectionStatusCode =
apiAvailability.isGooglePlayServicesAvailable(this);
if (apiAvailability.isUserResolvableError(connectionStatusCode)) {
showGooglePlayServicesAvailabilityErrorDialog(connectionStatusCode);
}
}
/**
* Display an error dialog showing that Google Play Services is missing
* or out of date.
* @param connectionStatusCode code describing the presence (or lack of)
* Google Play Services on this device.
*/
void showGooglePlayServicesAvailabilityErrorDialog(
final int connectionStatusCode) {
GoogleApiAvailability apiAvailability = GoogleApiAvailability.getInstance();
Dialog dialog = apiAvailability.getErrorDialog(
MainActivity.this,
connectionStatusCode,
REQUEST_GOOGLE_PLAY_SERVICES);
dialog.show();
}
/**
* An asynchronous task that handles the Google Sheets API call.
* Placing the API calls in their own task ensures the UI stays responsive.
*/
private class MakeRequestTask extends AsyncTask<Void, Void, List<String>> {
private com.google.api.services.sheets.v4.Sheets mService = null;
private Exception mLastError = null;
MakeRequestTask(GoogleAccountCredential credential) {
HttpTransport transport = AndroidHttp.newCompatibleTransport();
JsonFactory jsonFactory = JacksonFactory.getDefaultInstance();
mService = new com.google.api.services.sheets.v4.Sheets.Builder(
transport, jsonFactory, credential)
.setApplicationName("Google Sheets API Android Quickstart")
.build();
}
/**
* Background task to call Google Sheets API.
* @param params no parameters needed for this task.
*/
@Override
protected List<String> doInBackground(Void... params) {
try {
return getDataFromApi();
} catch (Exception e) {
mLastError = e;
cancel(true);
return null;
}
}
/**
* Fetch a list of names and majors of students in a sample spreadsheet:
* https://docs.google.com/spreadsheets/d/1BxiMVs0XRA5nFMdKvBdBZjgmUUqptlbs74OgvE2upms/edit
* @return List of names and majors
*/
private List<String> getDataFromApi() throws IOException {
String spreadsheetId = "1KlflsDsBn0lhGT87OuRuy_RGOuBP2jBU5zpqn_UIYT0";
String range = "Sheet1!A2:B";
List<String> results = new ArrayList<String>();
ValueRange response = this.mService.spreadsheets().values()
.get(spreadsheetId, range)
.execute();
List<List<Object>> values = response.getValues();
for (List row : values) {
//Obtains the row from the Google Sheet
teamAF.add(new Team(row.get(0).toString(), row.get(1).toString()));
}
//Shuffle the cards with the data on them.
Collections.shuffle(teamAF, new Random());
/*for(String s : results) {
Log.e("HERE", s);
}*/
return results;
}
@Override
protected void onPreExecute() {
//mOutputText.setText("");
mProgress.show();
}
@Override
protected void onPostExecute(List<String> output) {
mProgress.hide();
if (output == null || output.size() == 0) {
//mOutputText.setText("No results returned.");
} else {
output.add(0, "Data retrieved using the Google Sheets API:");
//mOutputText.setText(TextUtils.join("\n", output));
}
}
@Override
protected void onCancelled() {
mProgress.hide();
if (mLastError != null) {
if (mLastError instanceof GooglePlayServicesAvailabilityIOException) {
showGooglePlayServicesAvailabilityErrorDialog(
((GooglePlayServicesAvailabilityIOException) mLastError)
.getConnectionStatusCode());
} else if (mLastError instanceof UserRecoverableAuthIOException) {
startActivityForResult(
((UserRecoverableAuthIOException) mLastError).getIntent(),
MainActivity.REQUEST_AUTHORIZATION);
} else {
//mOutputText.setText("The following error occurred:\n"
//+ mLastError.getMessage());
}
} else {
//mOutputText.setText("Request cancelled.");
}
}
}
}
我的适配器：
package com.example.whateverthefuckyouwant;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import java.util.ArrayList;
import java.util.Random;
/**
* Created by ebuttikofer20 on 1/20/17.
*/
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> {
private ArrayList<Team> mDataset;
// Provide a reference to the views for each data item
// Complex data items may need more than one view per item, and
// you provide access to all the views for a data item in a view holder
public static class ViewHolder extends RecyclerView.ViewHolder {
// each data item is just a string in this case
public TextView mTextView;
public TextView left;
public TextView right;
public ViewHolder(View v) {
super(v);
mTextView = (TextView) v.findViewById(R.id.info_text);
left = (TextView) v.findViewById(R.id.left);
right = (TextView) v.findViewById(R.id.right);
}
}
// Provide a suitable constructor (depends on the kind of dataset)
public MyAdapter(ArrayList<Team> myDataset) {
mDataset = myDataset;
}
// Create new views (invoked by the layout manager)
@Override
public MyAdapter.ViewHolder onCreateViewHolder(ViewGroup parent,
int viewType) {
// create a new view
View v = LayoutInflater.from(parent.getContext())
.inflate(R.layout.my_text_view, parent, false);
// set the view's size, margins, paddings and layout parameters
ViewHolder vh = new ViewHolder(v);
return vh;
}
// Replace the contents of a view (invoked by the layout manager)
@Override
public void onBindViewHolder(ViewHolder holder, int position) {
// - get element from your data at this position
// - replace the contents of the view with that element
holder.mTextView.setText(mDataset.get(position).getTeamName());
Random gen = new Random();
if(gen.nextBoolean()) {
lefter = mDataset.get(position).getTeamNumber();
righter = mDataset.get(gen.nextInt(mDataset.size())).getTeamNumber();
holder.left.setText(lefter);
holder.right.setText(righter);
} else {
righter = mDataset.get(
position).getTeamNumber();
lefter = mDataset.get(gen.nextInt(mDataset.size())).getTeamNumber();
holder.right.setText(righter);
holder.left.setText(lefter);
}
}
String righter;
String lefter;
public String getLeft() {
return lefter;
}
public String getRighter() {
return righter;
}
// Return the size of your dataset (invoked by the layout manager)
@Override
public int getItemCount() {
return mDataset.size();
}
}
答案 0 :(得分：0)
将您的父布局在R.layout.my_text_view文件中的高度设置为wrap_content
答案 1 :(得分：0)
我遇到了同样的挑战，但是我不得不将父级布局高度设置为android:layout_height="wrap_content"
对我来说效果很好