我的应用程序中有一个RecyclerView，由listadapter填充。但有些元素在滚动后会丢失，甚至在开始时都不会显示出来。在这里，我在我的Activity中调用ListAdapter：
ListAdapter adapter = new ListAdapter(posts, new View.OnClickListener() {
@Override
public void onClick(final View v) {
new Thread(new Runnable() {
@Override
public void run() {
final PostViewHolder holder = new PostViewHolder(v);
final Intent intent = new Intent(MainActivity.this, PostViewActivity.class);
intent.setAction(Intent.ACTION_SEND);
intent.setType("image/png");
final int type = Integer.parseInt((String) holder.cardView.getTag(R.string.ident_type));
Log.e("TYPE", "" + type);
final String username = (String) holder.cardView.getTag(R.string.ident_username);
if (type == 2) {
holder.imagePost.setTransitionName(getString(R.string.transition_image));
PostViewActivity post;
int postWidth = 0;
int postHeight = 0;
postWidth = holder.imagePost.getWidth();
postHeight = holder.imagePost.getHeight();
Drawable drawable = holder.imagePost.getDrawable();
Bitmap photo = ((BitmapDrawable) drawable).getBitmap();
String path = MediaStore.Images.Media.insertImage(getContentResolver(), photo, "pic", null);
Uri uri = Uri.parse(path);
intent.putExtra(Intent.EXTRA_STREAM, uri);
intent.putExtra("dim", postWidth + "/" + postHeight);
} else {
}
activity.runOnUiThread(new Runnable() {
@Override
public void run() {
ActivityOptionsCompat options;
Pair<View, String> imagePair;
if (type == 2) {
imagePair = Pair.create((View) holder.imagePost, getString(R.string.transition_image));
options = ActivityOptionsCompat.makeSceneTransitionAnimation(MainActivity.this, imagePair);
} else {
options = ActivityOptionsCompat.makeSceneTransitionAnimation(MainActivity.this);
}
String id = (String) holder.cardView.getTag(R.string.ident_id);
intent.putExtra("type", type);
intent.putExtra("username", username);
intent.putExtra("id", id);
startActivity(intent, options.toBundle());
}
});
}
}).start();
}
}, width, height, context, activity);
RecyclerView rv = (RecyclerView) findViewById(R.id.user_interface_recycler);
StaggeredGridLayoutManager lm = new StaggeredGridLayoutManager(1, StaggeredGridLayoutManager.VERTICAL);
rv.setLayoutManager(lm);
rv.setAdapter(adapter);
以下是listadapter本身：
public class ListAdapter extends RecyclerView.Adapter<ListAdapter.PostViewHolder> {
List<Post> posts;
View.OnClickListener listener;
int width;
int height;
private Context context;
public static final String URL = "http://" + Connection.HOSTNAME + "/story/images/";
MainActivity activity;
public ListAdapter(List<Post> posts, View.OnClickListener listener, int width, int height, Context context, MainActivity activity) {
this.posts = posts;
this.listener = listener;
this.width = width;
this.height = height;
this.context = context;
this.activity = activity;
}
int placeholder = 0;
@Override
public int getItemCount() {
return posts.size();
}
@Override
public PostViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
View v = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.insert_layout, viewGroup, false);
PostViewHolder pvh = new PostViewHolder(v);
return pvh;
}
@Override
public void onBindViewHolder(final PostViewHolder postViewHolder, int i) {
Log.e("NUMBER" + i, posts.get(i).getType()+"");
switch (posts.get(i).getType()) {
case 1:
postViewHolder.layoutPhoto.setVisibility(View.GONE);
textPost(postViewHolder, i);
break;
case 2:
postViewHolder.layoutText.setVisibility(View.GONE);
imagePost(postViewHolder, i);
break;
}
}
private void imagePost(final PostViewHolder postViewHolder, final int i) {
BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
new Thread(new Runnable() {
@Override
public void run() {
String mainText = posts.get(i).getText();
if (mainText.length() > 100 && posts.get(i).getType() == 2) {
mainText = mainText.substring(0, 100);
mainText += "(...)";
}
Calendar calendar = Calendar.getInstance();
calendar.setTimeInMillis(posts.get(i).getTime());
if (posts.get(i).getTime() > MainActivity.minTime) {
MainActivity.minTime = posts.get(i).getTime();
}
int mYear = calendar.get(Calendar.YEAR);
int mMonth = calendar.get(Calendar.MONTH);
int mDay = calendar.get(Calendar.DAY_OF_MONTH);
int mMin = calendar.get(Calendar.MINUTE);
int mHour = calendar.get(Calendar.HOUR);
String mmin;
if (mMin < 10) {
mmin = 0 + "" + mMin;
} else {
mmin = Integer.toString(mMin);
}
String mhour;
if (mHour < 10) {
mhour = 0 + "" + mHour;
} else {
mhour = Integer.toString(mHour);
}
String resultdate = mDay + "." + (mMonth + 1) + "." + mYear + " " + mhour + ":" + mmin;
String storyName = posts.get(i).getStory().getName();
String insertText = posts.get(i).getText() + " by " + posts.get(i).getUsername() + "\n" + resultdate + "\n " + storyName;
final Spannable spannable = new SpannableString(insertText);
spannable.setSpan(new ForegroundColorSpan(context.getResources().getColor(R.color.colorAccent)), (posts.get(i).getText() + " by ").length(), insertText.length() - resultdate.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
spannable.setSpan(new ForegroundColorSpan(context.getResources().getColor(R.color.colorDezent)), posts.get(i).getText().length(), (posts.get(i).getText() + " by ").length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
spannable.setSpan(new RelativeSizeSpan(1f), (posts.get(i).getText() + " by " + posts.get(i).getUsername() + "\n").length(), insertText.length() - storyName.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
spannable.setSpan(new ForegroundColorSpan(context.getResources().getColor(R.color.colorDezent)), (posts.get(i).getText() + " by " + posts.get(i).getUsername() + "\n").length(), insertText.length() - storyName.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
spannable.setSpan(new ForegroundColorSpan(context.getResources().getColor(R.color.colorPrimaryDark)), insertText.length() - storyName.length(), insertText.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
activity.runOnUiThread(new Runnable() {
@Override
public void run() {
Log.e("photo", "photo");
postViewHolder.cv.setTag(R.string.ident_type, Integer.toString(posts.get(i).getType()));
postViewHolder.cv.setTag(R.string.ident_id, Integer.toString(posts.get(i).getID()));
int imgWidth = (int) ((float) width / 6);
int imgHeight = (int) ((float) width / 6);
Picasso.with(context).load(ListAdapter.URL + posts.get(i).getImageUser() + ".png").transform(new CircleTransform()).resize(imgWidth, imgHeight).centerCrop().into(postViewHolder.photoUserPhoto);
Picasso.with(context).load(ListAdapter.URL + posts.get(i).getImagePost() + ".png").resize(width, 500).centerCrop().into(postViewHolder.photoPostPhoto);
postViewHolder.photoText.setText(spannable);
postViewHolder.photoPostPhoto.setTransitionName("");
postViewHolder.itemView.setOnClickListener(listener);
postViewHolder.cv.setTag(R.string.ident_username, posts.get(i).getUsername());
}
});
}
}
).start();
}
private void textPost(final PostViewHolder postViewHolder, final int i) {
new Thread(new Runnable() {
@Override
public void run() {
String mainText = posts.get(i).getText();
Long postdate = posts.get(i).getTime();
String username = posts.get(i).getUsername();
//Bitmap userPhoto = posts.get(i).getImageUser();
Calendar calendar = Calendar.getInstance();
calendar.setTimeInMillis(posts.get(i).getTime());
if (posts.get(i).getTime() > MainActivity.minTime) {
MainActivity.minTime = posts.get(i).getTime();
}
int mYear = calendar.get(Calendar.YEAR);
int mMonth = calendar.get(Calendar.MONTH);
int mDay = calendar.get(Calendar.DAY_OF_MONTH);
int mMin = calendar.get(Calendar.MINUTE);
int mHour = calendar.get(Calendar.HOUR);
String mmin;
if (mMin < 10) {
mmin = 0 + "" + mMin;
} else {
mmin = Integer.toString(mMin);
}
String mhour;
if (mHour < 10) {
mhour = 0 + "" + mHour;
} else {
mhour = Integer.toString(mHour);
}
String resultdate = mDay + "." + (mMonth + 1) + "." + mYear + " " + mhour + ":" + mmin;
String storyName = posts.get(i).getStory().getName();
String insertText = posts.get(i).getText() + " by " + posts.get(i).getUsername() + "\n" + resultdate + "\n " + storyName;
final Spannable spannable = new SpannableString(insertText);
spannable.setSpan(new ForegroundColorSpan(context.getResources().getColor(R.color.colorAccent)), (posts.get(i).getText() + " by ").length(), insertText.length() - resultdate.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
spannable.setSpan(new ForegroundColorSpan(context.getResources().getColor(R.color.colorDezent)), posts.get(i).getText().length(), (posts.get(i).getText() + " by ").length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
spannable.setSpan(new RelativeSizeSpan(0.8f), (posts.get(i).getText() + " by " + posts.get(i).getUsername() + "\n").length(), insertText.length() - storyName.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
spannable.setSpan(new ForegroundColorSpan(context.getResources().getColor(R.color.colorDezent)), (posts.get(i).getText() + " by " + posts.get(i).getUsername() + "\n").length(), insertText.length() - storyName.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
spannable.setSpan(new ForegroundColorSpan(context.getResources().getColor(R.color.colorPrimaryDark)), insertText.length() - storyName.length(), insertText.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
activity.runOnUiThread(new Runnable() {
@Override
public void run() {
Log.e("text", "text");
postViewHolder.textUser.setText(spannable);
int imgWidth = (int) ((float) width / 6);
int imgHeight = (int) ((float) width / 6);
Picasso.with(context).load(ListAdapter.URL + posts.get(i).getImageUser() + ".png").transform(new CircleTransform()).resize(imgWidth, imgHeight).centerCrop().into(postViewHolder.textUserPhoto);
postViewHolder.itemView.setOnClickListener(listener);
postViewHolder.cv.setTag(R.string.ident_type, Integer.toString(posts.get(i).getType()));
postViewHolder.cv.setTag(R.string.ident_id, Integer.toString(posts.get(i).getID()));
postViewHolder.cv.setTag(R.string.ident_username, posts.get(i).getUsername());
}
});
}
}).start();
}
@Override
public void onAttachedToRecyclerView(RecyclerView recyclerView) {
super.onAttachedToRecyclerView(recyclerView);
}
public class PostViewHolder extends RecyclerView.ViewHolder {
CardView cv;
LinearLayout layoutPhoto;
TextView photoText;
ImageView photoPostPhoto;
ImageView photoUserPhoto;
LinearLayout layoutText;
TextView textUser;
ImageView textUserPhoto;
PostViewHolder(View itemView) {
super(itemView);
cv = (CardView) itemView.findViewById(R.id.cv);
photoText = (TextView) itemView.findViewById(R.id.photo_user_text);
photoPostPhoto = (ImageView) itemView.findViewById(R.id.photo_postPhoto);
layoutPhoto = (LinearLayout) itemView.findViewById(R.id.insert_layout_photo);
photoUserPhoto = (ImageView) itemView.findViewById(R.id.photo_username_photo);
layoutText = (LinearLayout) itemView.findViewById(R.id.insert_layout_text);
textUser = (TextView) itemView.findViewById(R.id.text_user_text);
textUserPhoto = (ImageView) itemView.findViewById(R.id.text_username_photo);
}
}
}
问题出在哪里？谢谢！
编辑：
fragment_main：
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v4.widget.SwipeRefreshLayout
android:id="@+id/activity_main_swipe_refresh_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<android.support.v7.widget.RecyclerView
android:id="@+id/post_list"
android:layout_width="match_parent"
android:layout_height="wrap_content">
</android.support.v7.widget.RecyclerView>
</android.support.v4.widget.SwipeRefreshLayout>
activity_main（这是一个coordinatorLayout，但这会被切掉。不知道为什么）：
<android.support.design.widget.AppBarLayout
android:id="@+id/appbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:paddingTop="@dimen/appbar_padding_top"
android:theme="@style/AppTheme.AppBarOverlay">
<android.support.v7.widget.Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
app:popupTheme="@style/AppTheme.PopupOverlay"
app:layout_scrollFlags="scroll|enterAlways|snap">
</android.support.v7.widget.Toolbar>
<android.support.design.widget.TabLayout
android:id="@+id/tabs"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</android.support.design.widget.AppBarLayout>
<android.support.v4.view.ViewPager
android:id="@+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="@string/appbar_scrolling_view_behavior" />
<android.support.design.widget.FloatingActionButton
android:id="@+id/fab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="end|bottom"
android:layout_margin="@dimen/fab_margin"
android:src="@android:drawable/ic_dialog_email" />
答案 0 :(得分：1)
在onBindViewHolder中，您将视图的一部分设置为GONE。您应该确保所有必要的部件都是可见的。试试这个（常量对于像这样的开关块的可读性是好的，特别是当它们变大时）：
private static final int TEXT_POST = 1;
private static final int IMAGE_POST = 2;
@Override
public void onBindViewHolder(final PostViewHolder postViewHolder, int i) {
Log.e("NUMBER" + i, posts.get(i).getType()+"");
switch (posts.get(i).getType()) {
case TEXT_POST:
postViewHolder.layoutText.setVisibility(View.VISIBLE);
postViewHolder.layoutPhoto.setVisibility(View.GONE);
textPost(postViewHolder, i);
break;
case IMAGE_POST:
postViewHolder.layoutText.setVisibility(View.GONE);
postViewHolder.layoutPhoto.setVisibility(View.VISIBLE);
imagePost(postViewHolder, i);
break;
default:
// probably unnecessary
postViewHolder.layoutText.setVisibility(View.VISIBLE);
postViewHolder.layoutPhoto.setVisibility(View.VISIBLE);
}
}
答案 1 :(得分：0)
在依赖项中使用最新的recyclerview版本，然后在xml文件中使用＆＃34; wrap_content＆＃34; 作为其高度