来自后端支持论坛。“此支持论坛仅针对与 Backendless 相关的问题。我们的 API 和后端服务之外的任何一般问题均不在支持范围内。请考虑发布到 stackoverflow.com 和/或 Android 论坛。” 马克·皮勒。
所以我在这里发布我的问题。在后端支持论坛上，我得到了一些宝贵的帮助来保存和检索关系，但现在我面临着“赞”按钮的另一个问题。我正在开发一个社交应用程序，其中有 3 个按钮：Like Comment Share。链接在我的后端支持线程： http: //support.backendless.com/topic/some-questions-regarding-data-loading-in-recyclerview-android 现在我正在尝试让 Like 按钮工作，但我面临以下问题：
如果您查看以下代码和我附上的屏幕截图，您会看到有一个未填充的“喜欢”心形按钮，这意味着我没有为该帖子点赞。在 2 号处，还有另一个按钮被填满，我点击了喜欢它，应用程序将我添加到喜欢该帖子的用户列表中。
if (user.getObjectId().equals(userId)) {
holder.like.setBackgroundResource(R.drawable.ic_star_rate_on);
holder.like.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
showToast();
}
});
} else {
holder.like.setBackgroundResource(R.drawable.ic_star_rate_off);
//onclick in another function: setLike(holder.like,holder.likes,feeds);
}
但问题是点击空心是行不通的。我尝试创建一个 toast 以检查单击是否有效并且 toast 没有出现。
但是，如果我单击我喜欢的项目（填充心形图标），它会向我显示我放置的吐司，以检查它是否听我的点击......
我尝试调试该应用程序，但调试窗口中没有出现任何内容……一切似乎都很正常，但无法找出代码有什么问题。我的适配器类如下：
public class FeedAdapter extends RecyclerView.Adapter<FeedAdapter.FeedsHolder> {
private List<Feeds> list;
private Context context;
private static String TAG = "MainActivity";
public FeedAdapter(Context context, List<Feeds> list) {
this.context = context;
this.list = list;
}
@Override
public FeedsHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.feed_item, parent, false);
return new FeedsHolder(view);
}
@Override
public void onBindViewHolder(final FeedsHolder holder, int position) {
//Starting Feeds
final Feeds feeds = list.get(position);
//Name
holder.name.setText(feeds.getOwner());
//Profile picture
holder.profilePictureURL = feeds.getProfilePictureURL();
//Image
holder.imageURL = feeds.getImageUrl();
//Getting date
Date myD = feeds.getCreated();
long ddate = myD.getTime();
String myDate = String.valueOf(DateUtils.getRelativeTimeSpanString(ddate, System.currentTimeMillis(), DateUtils.SECOND_IN_MILLIS));
holder.timeAgo.setText("• " + myDate);
//Get total likes
final int i = feeds.getLikes();
//Query
QueryOptions options = new QueryOptions();
options.setRelated( Arrays.asList( "usersThatLike" ) );
BackendlessDataQuery query = new BackendlessDataQuery();
query.setQueryOptions( options );
// getting all saved feeds with related users
Backendless.Data.of(Feeds.class).find(query, new AsyncCallback<BackendlessCollection<Feeds>>() {
@Override
public void handleResponse(BackendlessCollection<Feeds> response) {
String userId = Backendless.UserService.CurrentUser().getObjectId();
for (Feeds feed: response.getCurrentPage()) {
List<BackendlessUser> likedUsers = feeds.getUsersThatLike();
for (BackendlessUser user : likedUsers)
if (user.getObjectId().equals(userId)) {
Log.d(TAG, "No -------------------------------------");
holder.like.setBackgroundDrawable(context.getResources().getDrawable(R.drawable.ic_star_rate_on));
holder.like.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Toast.makeText(context, "You already like this item", Toast.LENGTH_SHORT).show();
}
});
} else {
holder.like.setBackgroundDrawable(context.getResources().getDrawable(R.drawable.ic_star_rate_off));
holder.like.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Log.d(TAG, "It should work +++++++++++++++++++++++++++++++");
// getting current user
Toast.makeText(context, "Arrived", Toast.LENGTH_SHORT).show();
BackendlessUser currentUser = Backendless.UserService.CurrentUser();
// adding current user as one who "liked" feed, you should implement "adding" by yourself
List<BackendlessUser> list = new ArrayList<>();
list.add(currentUser);
feeds.setUsersThatLike(list);
holder.like.setBackgroundDrawable(context.getResources().getDrawable(R.drawable.ic_star_rate_on));
feeds.setLikes(i + 1);
Backendless.Data.of(Feeds.class).save(feeds, new AsyncCallback<Feeds>() {
@Override
public void handleResponse(Feeds feeds) {
int likes = feeds.getLikes();
if (likes == 1) {
holder.likes.setText(i + 1 + " like");
} else {
holder.likes.setText(i + 1 + " likes");
}
}
@Override
public void handleFault(BackendlessFault backendlessFault) {
}
});
}
});
}
}
}
@Override
public void handleFault(BackendlessFault backendlessFault) {
}
});
holder.status.setText(feeds.getStatus());
String thisString = "no";
String myImageString = "no";
Picasso.with(context).load(holder.profilePictureURL).placeholder(R.drawable.placeholder).into(holder.profilePicture);
String image = feeds.getIsImageUrlEmpty();
if (!image.equals(myImageString)) {
holder.image.setVisibility(View.GONE);
holder.tagStatusBottom.setVisibility(View.VISIBLE);
holder.tagImageBottom.setVisibility(View.GONE);
} else {
holder.image.setVisibility(View.VISIBLE);
holder.tagStatusBottom.setVisibility(View.GONE);
holder.tagImageBottom.setVisibility(View.VISIBLE);
Picasso.with(context).load(holder.imageURL).placeholder(R.drawable.placeholder).into(holder.image);
}
String myString = feeds.getIsTagEmpty();
if (myString.equals(thisString)){
holder.tagImageBottom.setVisibility(View.VISIBLE);
if (!image.equals(myImageString)) {
holder.image.setVisibility(View.GONE);
holder.tagStatusBottom.setVisibility(View.VISIBLE);
holder.tagImageBottom.setVisibility(View.GONE);
} else {
holder.image.setVisibility(View.VISIBLE);
holder.tagStatusBottom.setVisibility(View.GONE);
holder.tagImageBottom.setVisibility(View.VISIBLE);
Picasso.with(context).load(holder.imageURL).placeholder(R.drawable.placeholder).into(holder.image);
}
} else {
holder.tagImageBottom.setVisibility(View.GONE);
holder.tagStatusBottom.setVisibility(View.GONE);
}
String str = feeds.getTag();
ArrayList<int[]> hashtagSpans1 = getSpans(str, '#');
SpannableString commentsContent1 =
new SpannableString(str);
setSpanComment(commentsContent1, hashtagSpans1) ;
holder.tagImageBottom.setText(commentsContent1);
holder.tagStatusBottom.setText(commentsContent1);
holder.tagImageBottom.setMovementMethod(LinkMovementMethod.getInstance());
int likes = feeds.getLikes();
if (likes == 1) {
holder.likes.setText(i +" like");
} else {
holder.likes.setText(i +" likes");
}
}
public ArrayList<int[]> getSpans(String body, char prefix) {
ArrayList<int[]> spans = new ArrayList<int[]>();
Pattern pattern = Pattern.compile(prefix + "\\w+");
Matcher matcher = pattern.matcher(body);
// Check all occurrences
while (matcher.find()) {
int[] currentSpan = new int[2];
currentSpan[0] = matcher.start();
currentSpan[1] = matcher.end();
spans.add(currentSpan);
}
return spans;
}
private void setSpanComment(SpannableString commentsContent, ArrayList<int[]> hashtagSpans) {
for(int i = 0; i < hashtagSpans.size(); i++) {
int[] span = hashtagSpans.get(i);
int hashTagStart = span[0];
int hashTagEnd = span[1];
commentsContent.setSpan(new Hashtag(context),
hashTagStart,
hashTagEnd, 0);
}
}
@Override
public int getItemCount() {
return list.size();
}
这是我的 Feed 课程：
public class Feeds
{
private String owner;
private String tag;
private String profilePictureURL;
private String imageURL;
private Date created;
private Date updated;
private String status;
private int likes;
private String isTagEmpty;
private String isImageUrlEmpty;
private List<BackendlessUser> usersThatLike;
public String getOwner()
{
return owner;
}
public void setOwner( String owner )
{
this.owner = owner;
}
public int getLikes()
{
return likes;
}
public void setLikes ( int likes )
{
this.likes = likes;
}
public String getIsTagEmpty()
{
return isTagEmpty;
}
public void setIsTagEmpty ( String isTagEmpty )
{
this.isTagEmpty = isTagEmpty;
}
public String getIsImageUrlEmpty()
{
return isImageUrlEmpty;
}
public void setIsImageUrlEmpty ( String isImageUrlEmpty )
{
this.isImageUrlEmpty = isImageUrlEmpty;
}
public String getStatus()
{
return status;
}
public void setStatus( String status )
{
this.status = status;
}
public String getTag()
{
return tag;
}
public void setTag( String tag )
{
this.tag = tag;
}
public String getProfilePictureURL()
{
return profilePictureURL;
}
public void setProfilePictureURL ( String profilePictureURL )
{
this.profilePictureURL = profilePictureURL;
}
public String getImageUrl()
{
return imageURL;
}
public void setImageUrl ( String imageURL )
{
this.imageURL = imageURL;
}
public Date getCreated()
{
return created;
}
public Date getUpdated()
{
return updated;
}
public List<BackendlessUser> getUsersThatLike() {
return usersThatLike;
}
public void setUsersThatLike(List<BackendlessUser> usersThatLike) {
this.usersThatLike = usersThatLike;
}
}
你能帮我吗？
编辑：在下面的答案中实现代码后它不起作用。这就是我编辑代码的方式：
//Skipped previous code. Posted only the changed code
Backendless.Data.of(Feeds.class).find(query, new AsyncCallback<BackendlessCollection<Feeds>>() {
@Override
public void handleResponse(final BackendlessCollection<Feeds> feedsBackendlessCollection) {
//Suggested by sihao
holder.like.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
String userId = Backendless.UserService.CurrentUser().getObjectId();
for (Feeds feed: feedsBackendlessCollection.getCurrentPage()) {
List<BackendlessUser> likedUsers = feeds.getUsersThatLike();
for (BackendlessUser user : likedUsers)
if (user.getObjectId().equals(userId)) {
Toast.makeText(context,"You already liked this item",Toast.LENGTH_SHORT).show();
} else {
// getting current user
BackendlessUser currentUser = Backendless.UserService.CurrentUser();
// adding current user as one who "liked" feed, you should implement "adding" by yourself
List<BackendlessUser> list = new ArrayList<>();
list.add(currentUser);
feeds.setUsersThatLike(list);
holder.like.setBackgroundDrawable(context.getResources().getDrawable(R.drawable.ic_star_rate_on));
feeds.setLikes(i + 1);
Backendless.Data.of(Feeds.class).save(feeds, new AsyncCallback<Feeds>() {
@Override
public void handleResponse(Feeds feeds) {
int likes = feeds.getLikes();
if (likes == 1) {
holder.likes.setText(i + 1 + " like");
} else {
holder.likes.setText(i + 1 + " likes");
}
}
@Override
public void handleFault(BackendlessFault backendlessFault) {
}
});
}
}
}
});
}
@Override
public void handleFault(BackendlessFault backendlessFault) {
}
});
更新：这些天我试图解决这个问题并得到了一个（好）的想法。我成功地将按钮背景从空心更改为填充用户喜欢的元素的心。我得到了以下想法：检查心脏是空的还是充满的。因此，在活动加载时，我的应用程序从“usersThatLike”列获取数据，如果用户存在于后端列表中，则设置填充心可绘制，如果不存在则设置为空心绘制。所以现在我正在尝试对可绘制对象进行检查。如果心脏比显示吐司“你已经喜欢这个项目”，否则将喜欢的项目添加到项目并将用户添加到当前项目的“usersThatLike”列。但它正在为所有项目返回“充满”的心。我的意思是说，即使可绘制的心脏是空的，它也会返回它'
//*** Skipped the query code. In handleResponse:
String userId = Backendless.UserService.CurrentUser().getObjectId();
for (Feeds feed: response.getData()) {
feed = list.get(position);
List<BackendlessUser> likedUsers = feed.getUsersThatLike();
for (BackendlessUser user : likedUsers)
if (user.getObjectId().equals(userId)) {
holder.like.setBackgroundResource(R.drawable.ic_star_rate_on);
} else if (!user.getObjectId().equals(userId)) {
holder.like.setBackgroundResource(R.drawable.ic_star_rate_off);
}
}
而不是在handleResponse之外，在查询代码之后的正常onBindViewHolder中，我正在检查drawable，如下所示：
//***HERE IS THE QUERY
Backendless.Data.of(Feeds.class).find(query, new AsyncCallback<BackendlessCollection<Feeds>>() {
//***SKIPPED FOR BREVITY
});
//***HERE IS THE CHECK
holder.like.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (holder.like.getBackground() != context.getDrawable(R.drawable.ic_star_rate_off)){
toast();
} else {
setLike();
}
}
});