我无法找到为什么我的复选框在从自定义适配器调用时无法选中。
上下文：我有一个RecyclerView，Recycler视图中的每个项目都包含一个图像，文本和一个复选框。列表中的每个项目对应一个Friend对象，可以选择其中一些朋友对象。
public class FriendSelectionAdapter extends RecyclerView.Adapter<FriendSelectionAdapter.FriendViewHolder> {
private final LayoutInflater inflater;
private List<Friend> friends;
private Context context;
private final OnItemClickListener listener;
private String TAG = "FriendSelectionAD";
public interface OnItemClickListener {
void onItemClick( Friend friend );
}
public FriendSelectionAdapter(Context context, List<Friend> friends, OnItemClickListener listener ) {
this.friends = friends;
this.context = context;
this.listener = listener;
this.inflater = LayoutInflater.from(context);
}
@Override
public FriendViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
final View itemView = inflater.inflate(R.layout.list_item_friend,parent,false);
return new FriendViewHolder(itemView);
}
@Override
public void onBindViewHolder(FriendViewHolder holder, int position) {
final Friend friend = friends.get(position);
holder.bind(friend, listener );
holder.checkbox.setChecked(true);
}
@Override
public int getItemCount() {
return friends.size();
}
public void setFriends( List<Friend> friends ) {
this.friends = new ArrayList<>(friends);
}
public Friend removeItem(int position) {
final Friend friend= friends.remove(position);
notifyItemRemoved(position);
return friend;
}
public void addItem(int position, Friend friend) {
friends.add(position, friend);
notifyItemInserted(position);
}
public void moveItem(int fromPosition, int toPosition) {
final Friend friend = friends.remove(fromPosition);
friends.add(toPosition, friend);
notifyItemMoved(fromPosition, toPosition);
}
public void animateTo(List<Friend> friends) {
applyAndAnimateRemovals(friends);
applyAndAnimateAdditions(friends);
applyAndAnimateMovedItems(friends);
}
private void applyAndAnimateRemovals(List<Friend> newFriends) {
for (int i = friends.size() - 1; i >= 0; i--) {
final Friend friend = friends.get(i);
if (!newFriends.contains(friend)) {
removeItem(i);
}
}
}
private void applyAndAnimateAdditions(List<Friend> newFriends) {
for (int i = 0, count = newFriends.size(); i < count; i++) {
final Friend friend = newFriends.get(i);
if (!friends.contains(friend)) {
addItem(i, friend);
}
}
}
private void applyAndAnimateMovedItems( List<Friend> newFriends ) {
for (int toPosition = newFriends.size() - 1; toPosition >= 0; toPosition--) {
final Friend friend = newFriends.get(toPosition);
final int fromPosition = friends.indexOf(friend);
if (fromPosition >= 0 && fromPosition != toPosition) {
moveItem(fromPosition, toPosition);
}
}
}
public class FriendViewHolder extends RecyclerView.ViewHolder {
private TextView nameView;
private CircleImageView profilePicture;
private CheckBox checkbox;
public FriendViewHolder( View view ) {
super(view);
this.nameView = (TextView)view.findViewById(R.id.item_friend_name);
this.profilePicture = (CircleImageView) view.findViewById(R.id.item_friend_profile_picture);
this.checkbox = (CheckBox) view.findViewById(R.id.item_friend_checkbox);
}
public void bind( final Friend friend, final OnItemClickListener listener ) {
nameView.setText(friend.getDisplayName());
String profileUrl = "https://graph.facebook.com/" + friend.getId() + "/picture?type=large";
Picasso.with(FriendSelectionAdapter.this.context).load(profileUrl).into(profilePicture);
checkbox.setChecked(true);
checkbox.setSelected(true);
/*
initialCheck( friend );
itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
itemClicked( friend );
}
});
checkbox.setOncheckListener(new CheckBox.OnCheckListener() {
@Override
public void onCheck(CheckBox checkbox, boolean b) {
itemClicked( friend );
}
});
*/
Log.e(TAG,"Binding friend - name: " + friend.getDisplayName() + " selected: " + friend.isSelected() );
}
private void itemClicked( Friend friend ) {
checkbox.setChecked( !friend.isSelected() );
friend.setSelected( !friend.isSelected() );
}
private void initialCheck( Friend friend ) {
checkbox.setChecked( friend.isSelected() );
}
}
}
每个项目都是这样的：
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="48dp"
android:clickable="true"
android:paddingStart="16dp"
android:paddingEnd="16dp"
android:background="?attr/selectableItemBackground">
<de.hdodenhof.circleimageview.CircleImageView
android:id="@+id/item_friend_profile_picture"
android:layout_width="40dp"
android:layout_height="40dp"
android:layout_gravity="center_vertical"
android:contentDescription="Facebook profile picture"/>
<TextView
android:id="@+id/item_friend_name"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:fontFamily="sans-serif"
android:layout_gravity="center_vertical"
android:paddingStart="72dp"
android:paddingEnd="0dp"
android:textSize="13sp" />
<com.gc.materialdesign.views.CheckBox
android:id="@+id/item_friend_checkbox"
android:background="@color/colorAccent"
android:layout_gravity="end|center_vertical"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:drawablePadding="2dp" />
</FrameLayout>
正在调用绑定方法，虽然令人困惑的是为什么复选框的UI没有更新。
谢谢！
答案 0 :(得分：1)
问题出在您的适配器
中public class FriendViewHolder extends RecyclerView.Adapter<FriendViewHolder .MyViewHolder> {
private ArrayList<Fr> arrayList = new ArrayList<>();
public class MyViewHolder extends RecyclerView.ViewHolder {
public TextView nameView;
public CircleImageView profilePicture;
public CheckBox checkbox;
public MyViewHolder(View view) {
super(view);
nameView = (TextView)view.findViewById(R.id.item_friend_name);
profilePicture = (CircleImageView) view.findViewById(R.id.item_friend_profile_picture);
checkbox = (CheckBox) view.findViewById(R.id.item_friend_checkbox);
}
}
public FriendViewHolder (ArrayList<ModelReviewOrder> modelReviewOrders) {
this.arrayList = modelReviewOrders;
}
@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View itemView = LayoutInflater.from(parent.getContext())
.inflate(R.layout.xml_of_each_row_of_list, parent, false);
return new MyViewHolder(itemView);
}
@Override
public void onBindViewHolder(MyViewHolder holder, int position) {
ModelReviewOrder modelReviewOrder = arrayList.get(position);
holder.nameView.setText(friend.getDisplayName());
String profileUrl = "https://graph.facebook.com/" + friend.getId() + "/picture?type=large";
Picasso.with(FriendSelectionAdapter.this.context).load(profileUrl).into(holder.profilePicture);
holder.checkbox.setChecked(true);
}
@Override
public int getItemCount() {
return arrayList.size();
}
}