当我从RecyclerView中删除一个项目时，我不再能够删除另一个项目。当我创建一个项目时，我也无法删除该项目和RecyclerView中的任何其他项目。
代码如下:
Home.java:
@Override
protected void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.home_activity);
itemImage = findViewById(R.id.image_holder);
itemName = findViewById(R.id.add_item_name);
itemPrice = findViewById(R.id.add_price);
itemDesc = findViewById(R.id.add_desc);
// Initialize Firebase Auth
mAuth = FirebaseAuth.getInstance();
addPhotoButton = findViewById(R.id.getCameraBtn);
addFileButton = findViewById(R.id.getGalleryBtn);
imageView = findViewById(R.id.image_holder);
addPhotoButton.setOnClickListener(this);
addFileButton.setOnClickListener(this);
itemList = new ArrayList<Item>();
// add item for testing
itemList.add(new Item(R.drawable.ic_logo, "Baby Stroller", "A stroller for baby", "59.99"));
recyclerView = findViewById(R.id.recyclerView);
recyclerView.setHasFixedSize(true);
layoutManager = new LinearLayoutManager(this);
adapter = new ItemAdapter(itemList);
recyclerView.setLayoutManager(layoutManager);
recyclerView.setAdapter(adapter);
adapter.setOnItemClickListener(new ItemAdapter.OnItemClickListener() {
@Override
public void onDeleteClick(int position) {
removeItem(position);
}
@Override
public void onEditClick(int position) {
editItem(position);
}
});
}
// log out back to start page
public void goToStart(View view){
Intent intent = new Intent(this, MainActivity.class);
startActivity(intent);
}
@Override
public void onClick(View view) {
switch (view.getId()) {
case R.id.getCameraBtn:
//post a photo from the camera
Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(takePictureIntent, CAMERA_CODE);
break;
case R.id.getGalleryBtn:
//post an image
Intent galleryIntent = new Intent(Intent.ACTION_GET_CONTENT);
galleryIntent.setType("image/*"); //anything that is image related
startActivityForResult(galleryIntent, GALLERY_CODE);
break;
}
}
@Override
protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == GALLERY_CODE && resultCode == RESULT_OK) {
if (data != null) {
imageUri = data.getData(); //we have the actual path
imageView.setImageURI(imageUri); //show image
}
} else if (requestCode == CAMERA_CODE && resultCode == RESULT_OK) {
Bundle extras = data.getExtras();
Bitmap imageBitmap = (Bitmap) extras.get("data");
imageView.setImageBitmap(imageBitmap);
}
}
public void addItem(View view){
if(itemName.getText().toString().trim().length() != 0 || itemPrice.getText().toString().trim().length() != 0 || itemDesc.getText().toString().trim().length() != 0){
itemList.add(new Item(R.drawable.ic_logo, itemName.getText().toString(), itemPrice.getText().toString(), itemDesc.getText().toString()));
adapter = new ItemAdapter(itemList);
recyclerView.setAdapter(adapter);
itemName.setText("");
itemPrice.setText("");
itemDesc.setText("");
}
else{
Toast.makeText(Home.this, "All fields must be filled when creating a new item.",
Toast.LENGTH_LONG).show();
}
}
public void removeItem(int position){
itemList.remove(position);
adapter.notifyItemChanged(position);
}
ItemAdapter.java:
public class ItemAdapter extends RecyclerView.Adapter<ItemAdapter.ViewHolder>{
private ArrayList<Item> ItemList;
private OnItemClickListener Listener;
public void setOnItemClickListener(OnItemClickListener listener) {Listener = listener;}
public interface OnItemClickListener{
void onDeleteClick(int position);
}
public static class ViewHolder extends RecyclerView.ViewHolder{
public ImageView item_image;
public TextView item_name;
public TextView item_desc;
public TextView item_price;
public ImageView deleteBtn;
public ImageView editBtn;
public ViewHolder(@NonNull View itemView, OnItemClickListener listener) {
super(itemView);
item_image = itemView.findViewById(R.id.item_image);
item_name = itemView.findViewById(R.id.item_name);
item_desc = itemView.findViewById(R.id.desc);
item_price = itemView.findViewById(R.id.price);
deleteBtn = itemView.findViewById(R.id.delete_item);
editBtn = itemView.findViewById(R.id.edit_item);
deleteBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if(listener != null){
int position = getAdapterPosition();
if (position != RecyclerView.NO_POSITION){
listener.onDeleteClick(position);
}
}
}
});
}
}
public ItemAdapter(ArrayList<Item> itemList) {ItemList = itemList;}
@NonNull
@Override
public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_items, parent, false);
ViewHolder vh = new ViewHolder(v, Listener);
return vh;
}
@Override
public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
Item currentItem = ItemList.get(position);
holder.item_image.setImageResource(currentItem.getItemImage());
holder.item_name.setText(currentItem.getItemName());
holder.item_desc.setText(currentItem.getItemDesc());
holder.item_price.setText(currentItem.getItemPrice());
}
@Override
public int getItemCount() {
return ItemList.size();
}
}
Item.java:
public class Item {
private int itemImage;
private String itemName;
private String itemDesc;
private String itemPrice;
public Item(int itemImage, String itemName, String itemDesc, String itemPrice){
this.itemImage = itemImage;
this.itemName = itemName;
this.itemDesc = itemDesc;
this.itemPrice = itemPrice;
}
public int getItemImage(){return itemImage;}
public String getItemName(){return itemName;}
public String getItemDesc(){return itemDesc;}
public String getItemPrice(){return itemPrice;}
}
当用户点击删除按钮时，它将第一次工作并删除该特定项，但当需要删除另一项时，该按钮没有响应。当用户添加了一个项目并且无法删除任何项目时，也会发生同样的情况。我不确定是什么原因造成的。谢谢。
编辑:当我将项目硬编码到RecyclerView中时，删除函数可以正常工作。只有在添加新项目时，它不再工作，包括硬编码的项目。
在Home.java中，您正在设置单击侦听器:
adapter.setOnItemClickListener(new ItemAdapter.OnItemClickListener() {...}
在addItem()中，您正在创建一个新的适配器:
adapter = new ItemAdapter(itemList);
问题是你从来没有在这个新的适配器上设置一个点击监听器。
我会考虑不创建新的适配器，而是调用notify方法来提醒适配器有新项。
尝试将adapter.notifyItemChanged(position);更改为adapter.notifyItemRemoved(position);
告诉适配器有一项更改了，而不是使用:
notifyDataSetChanged()
这将重新加载所有项