RecyclerView滚动进行更改 [英] RecyclerView scrolling makes changes
问题描述
我有一个RecyclerView，它具有一个自定义适配器，可以使rowLayout膨胀.每行包含一个CardView，其中包含一些文本和图像作为按钮.特别是我有一个喜欢"按钮(ImageView)，到目前为止，该按钮仅应在单击时更改imageResource.
I have a RecyclerView which has a custom adapter that inflates a rowLayout. Each Row contains a CardView and in it some text and images as buttons. In particular i have a "like" button(ImageView) that as for now only is supposed to change imageResource on click.
我能够在onBindViewHolder()方法中设置一个onClicklistener，并且当我单击按钮时它确实会注册，但是它不仅会更改该按钮的图像，还会更改其他一些按钮，例如按钮我向下滚动，然后再次向上滚动，第一个赞"按钮有时会重置.
I was able to set an onClicklistener in the onBindViewHolder() method and it does indeed register when i click the button, however it not only changes that buttons image but it also changes some of the other like buttons and also when i scroll down and then up again the first like button sometimes get reset.
这是我的适配器代码.
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> implements View.OnClickListener {
private ArrayList<WallPost> wallPosts;
@Override
public void onClick(View v) {
}
public static class ViewHolder extends RecyclerView.ViewHolder {
public View view;
public ViewHolder(View v) {
super(v);
view = v;
}
}
public MyAdapter(ArrayList<WallPost> wallPosts) {
this.wallPosts = wallPosts;
}
@Override
public MyAdapter.ViewHolder onCreateViewHolder(ViewGroup parent,
int viewType) {
View v = LayoutInflater.from(parent.getContext())
.inflate(R.layout.item_layout, parent, false);
ViewHolder vh = new ViewHolder(v);
return vh;
}
@Override
public void onBindViewHolder(ViewHolder holder, final int position) {
TextView name = (TextView) holder.view.findViewById(R.id.person_name);
TextView age = (TextView) holder.view.findViewById(R.id.person_age);
ImageView profile = (ImageView) holder.view.findViewById(R.id.person_photo);
TextView description = (TextView) holder.view.findViewById(R.id.description_text);
AppCompatImageView mainImage = (AppCompatImageView) holder.view.findViewById(R.id.main_image);
final ImageView likeButton = (ImageView) holder.view.findViewById(R.id.like_button);
name.setText(wallPosts.get(position).getName());
age.setText(wallPosts.get(position).getAge());
profile.setImageResource(wallPosts.get(position).getPhotoId());
description.setText(wallPosts.get(position).getDescription());
mainImage.setImageResource(wallPosts.get(position).getMainPhotoId());
likeButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
likeButton.setImageResource(R.drawable.favourite_red);
}
});
}
@Override
public int getItemCount() {
return wallPosts.size();
}
}
这是项目布局
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView xmlns:card_view="http://schemas.android.com/apk/res-auto"
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/cv"
android:layout_marginLeft="8dp"
android:layout_marginRight="8dp"
android:layout_marginBottom="10dp"
card_view:cardCornerRadius="5dp">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="8dp"
>
<de.hdodenhof.circleimageview.CircleImageView
android:layout_width="48dp"
android:layout_height="48dp"
android:id="@+id/person_photo"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_marginRight="16dp"
android:src="@drawable/placeholderprofilepic"
/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/person_name"
android:text="Name"
android:layout_toRightOf="@+id/person_photo"
android:layout_alignParentTop="true"
android:textSize="30sp"
/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/person_age"
android:text="19"
android:layout_toRightOf="@+id/person_photo"
android:layout_below="@+id/person_name"
/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/description_text"
android:text="This is the description of the image"
android:layout_below="@id/person_age"/>
<android.support.v7.widget.AppCompatImageView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/main_image"
android:src="@drawable/placeholderfoodimage"
android:layout_below="@+id/description_text"
android:elevation="4dp"/>
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/like_button"
android:src="@drawable/favoruite_hollow"
android:layout_marginTop="10dp"
android:layout_below="@+id/main_image"
/>
</RelativeLayout>
</android.support.v7.widget.CardView>
推荐答案
这是由于回收视图所致.您需要修改您的getView()方法并执行以下两项操作-
This is due to recycling of views . You need to modify your getView() method and do these 2 things -
-
修改您的
WallPost类，使其具有用于设置like标志的标志.在onClickListener中设置此标志并更新wallPosts数据集.
Modify your
WallPostclass to have a flag to set the like flag. Set this flag inonClickListenerand update yourwallPostsdataset .
wallPosts.get(position).setLike(true);
每次根据您在列表对象中拥有的like标志设置喜欢/不喜欢"图像资源-
Set the like/not like image resource everytime based on the like flag you own in your list objects -
if(wallPosts.get(position).isLiked()){
likeButton.setImageResource(R.drawable.favourite_red);
} else{
likeButton.setImageResource(R.drawable.favoruite_hollow);
}
if(wallPosts.get(position).isLiked()){
likeButton.setImageResource(R.drawable.favourite_red);
} else{
likeButton.setImageResource(R.drawable.favoruite_hollow);
}
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