无法解析 java.lang.ClassCastException
Unable to resolve java.lang.ClassCastException
我正在尝试开发我的第一个 android 应用程序，但遇到以下错误 - 'java.lang.ClassCastException。这是我的 java 代码：
package com.example.fresh24;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;
import java.util.List;
public class CartAdapter extends RecyclerView.Adapter {
private List<CartItemModel> cartItemModelList;
public CartAdapter(List<CartItemModel> cartItemModelList) {
this.cartItemModelList = cartItemModelList;
}
@Override
public int getItemViewType(int position) {
switch (cartItemModelList.get(position).getType()) {
case 0:
return CartItemModel.CART_ITEM;
case 1:
return CartItemModel.TOTAL_AMOUNT;
default:
return -1;
}
}
@NonNull
@Override
public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int viewType) {
switch (viewType) {
case CartItemModel.CART_ITEM:
View cartItemView = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.cart_item_layout, viewGroup, false);
return new CartItemViewHolder(cartItemView);
case CartItemModel.TOTAL_AMOUNT:
View cartTotalView = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.cart_total_amount_layout, viewGroup, false);
return new CartItemViewHolder(cartTotalView);
default:
return null;
}
}
@Override
public void onBindViewHolder(@NonNull RecyclerView.ViewHolder viewHolder, int position) {
switch (cartItemModelList.get(position).getType()) {
case CartItemModel.CART_ITEM:
int resource = cartItemModelList.get(position).getProductImage();
String title = cartItemModelList.get(position).getProducTitle();
int freeCoupons = cartItemModelList.get(position).getFreeCoupons();
String productPrice = cartItemModelList.get(position).getProductPrice();
String cutPrice = cartItemModelList.get(position).getCutPrice();
int offersApplied = cartItemModelList.get(position).getOffersApplied();
((CartItemViewHolder)viewHolder).setItemDetails(resource,title,freeCoupons,productPrice,cutPrice,offersApplied);
break;
case CartItemModel.TOTAL_AMOUNT:
String totalItems = cartItemModelList.get(position).getTotalItems();
String totalItemsPrice = cartItemModelList.get(position).getTotalItemPrice();
String conveniencePrice = cartItemModelList.get(position).getConveniencePrice();
String totalAmount = cartItemModelList.get(position).getTotalAmount();
String savedAmount = cartItemModelList.get(position).getSavedAmount();
((CartTotalAmountViewHolder)viewHolder).setTotalAmount(totalItems,totalItemsPrice,conveniencePrice,totalAmount,savedAmount);
break;
default:
return;
}
}
@Override
public int getItemCount() {
return cartItemModelList.size();
}
class CartItemViewHolder extends RecyclerView.ViewHolder {
private ImageView productImage;
private ImageView freecouponIcon;
private TextView productTitle;
private TextView freeCoupons;
private TextView productPrice;
private TextView productCutPrice;
private TextView offersApplied;
/*private TextView couponsApplied;
private TextView productQuantity;*/
public CartItemViewHolder(@NonNull View itemView) {
super(itemView);
productImage = itemView.findViewById(R.id.product_image);
productTitle = itemView.findViewById(R.id.product_title);
freecouponIcon = itemView.findViewById(R.id.free_coupon_icon);
freeCoupons = itemView.findViewById(R.id.tv_free_coupon);
productPrice = itemView.findViewById(R.id.product_price);
productCutPrice = itemView.findViewById(R.id.cut_price);
offersApplied = itemView.findViewById(R.id.offers_applied);
}
private void setItemDetails(int resource, String title, int freeCouponsNo, String productPriceText, String productCutPriceText, int offersAppliedNo) {
productImage.setImageResource(resource);
productTitle.setText(title);
if (freeCouponsNo > 0) {
freecouponIcon.setVisibility(View.VISIBLE);
freeCoupons.setVisibility(View.VISIBLE);
if (freeCouponsNo == 1) {
freeCoupons.setText("free " + freeCouponsNo + " Coupon");
} else {
freeCoupons.setText("free " + freeCouponsNo + " Coupons");
}
} else {
freecouponIcon.setVisibility(View.INVISIBLE);
freeCoupons.setVisibility(View.INVISIBLE);
}
productPrice.setText(productPriceText);
productCutPrice.setText(productCutPriceText);
if (offersAppliedNo > 0) {
offersApplied.setVisibility(View.VISIBLE);
offersApplied.setText(offersAppliedNo + "Offers Applied");
} else {
offersApplied.setVisibility(View.INVISIBLE);
}
}
}
class CartTotalAmountViewHolder extends RecyclerView.ViewHolder {
private TextView totalItems;
private TextView totalItemPrice;
private TextView conveniencePrice;
private TextView totalAmount;
private TextView savedAmount;
public CartTotalAmountViewHolder(@NonNull View itemView) {
super(itemView);
totalItems = itemView.findViewById(R.id.total_items);
totalItemPrice = itemView.findViewById(R.id.total_items_price);
conveniencePrice = itemView.findViewById(R.id.convenience_price);
totalAmount = itemView.findViewById(R.id.total_price);
savedAmount = itemView.findViewById(R.id.saved_amount);
}
private void setTotalAmount(String totalItemText, String totalItemPriceText, String conveniencePriceText, String totalAmountText, String savedAmountText) {
totalItems.setText(totalItemText);
totalItemPrice.setText(totalItemPriceText);
conveniencePrice.setText(conveniencePriceText);
totalAmount.setText(totalAmountText);
savedAmount.setText(savedAmountText);
}
}
}
这里是完整的堆栈跟踪：
2019-08-01 09:51:45.298 26950-26950/com.example.fresh24 E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.fresh24, PID: 26950
java.lang.ClassCastException: com.example.fresh24.CartAdapter$CartItemViewHolder cannot be cast to com.example.fresh24.CartAdapter$CartTotalAmountViewHolder
at com.example.fresh24.CartAdapter.onBindViewHolder(CartAdapter.java:67)
at androidx.recyclerview.widget.RecyclerView$Adapter.onBindViewHolder(RecyclerView.java:6781)
at androidx.recyclerview.widget.RecyclerView$Adapter.bindViewHolder(RecyclerView.java:6823)
at androidx.recyclerview.widget.RecyclerView$Recycler.tryBindViewHolderByDeadline(RecyclerView.java:5752)
at androidx.recyclerview.widget.RecyclerView$Recycler.tryGetViewHolderForPositionByDeadline(RecyclerView.java:6019)
at androidx.recyclerview.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5858)
at androidx.recyclerview.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5854)
at androidx.recyclerview.widget.LinearLayoutManager$LayoutState.next(LinearLayoutManager.java:2230)
at androidx.recyclerview.widget.LinearLayoutManager.layoutChunk(LinearLayoutManager.java:1557)
at androidx.recyclerview.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1517)
at androidx.recyclerview.widget.LinearLayoutManager.onLayoutChildren(LinearLayoutManager.java:612)
at androidx.recyclerview.widget.RecyclerView.dispatchLayoutStep2(RecyclerView.java:3924)
at androidx.recyclerview.widget.RecyclerView.dispatchLayout(RecyclerView.java:3641)
at androidx.recyclerview.widget.RecyclerView.onLayout(RecyclerView.java:4194)
at android.view.View.layout(View.java:17523)
at android.view.ViewGroup.layout(ViewGroup.java:5612)
at androidx.constraintlayout.widget.ConstraintLayout.onLayout(ConstraintLayout.java:1915)
at android.view.View.layout(View.java:17523)
at android.view.ViewGroup.layout(ViewGroup.java:5612)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:323)
at android.widget.FrameLayout.onLayout(FrameLayout.java:261)
at android.view.View.layout(View.java:17523)
at android.view.ViewGroup.layout(ViewGroup.java:5612)
at com.google.android.material.appbar.HeaderScrollingViewBehavior.layoutChild(HeaderScrollingViewBehavior.java:142)
at com.google.android.material.appbar.ViewOffsetBehavior.onLayoutChild(ViewOffsetBehavior.java:41)
at com.google.android.material.appbar.AppBarLayout$ScrollingViewBehavior.onLayoutChild(AppBarLayout.java:1556)
at androidx.coordinatorlayout.widget.CoordinatorLayout.onLayout(CoordinatorLayout.java:888)
at android.view.View.layout(View.java:17523)
at android.view.ViewGroup.layout(ViewGroup.java:5612)
at androidx.drawerlayout.widget.DrawerLayout.onLayout(DrawerLayout.java:1231)
at android.view.View.layout(View.java:17523)
at android.view.ViewGroup.layout(ViewGroup.java:5612)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:323)
at android.widget.FrameLayout.onLayout(FrameLayout.java:261)
at android.view.View.layout(View.java:17523)
at android.view.ViewGroup.layout(ViewGroup.java:5612)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1741)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1585)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1494)
at android.view.View.layout(View.java:17523)
at android.view.ViewGroup.layout(ViewGroup.java:5612)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:323)
at android.widget.FrameLayout.onLayout(FrameLayout.java:261)
at android.view.View.layout(View.java:17523)
at android.view.ViewGroup.layout(ViewGroup.java:5612)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1741)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1585)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1494)
at android.view.View.layout(View.java:17523)
at android.view.ViewGroup.layout(ViewGroup.java:5612)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:323)
at android.widget.FrameLayout.onLayout(FrameLayout.java:261)
2019-08-01 09:51:45.298 26950-26950/com.example.fresh24 E/AndroidRuntime: at com.android.internal.policy.DecorView.onLayout(DecorView.java:724)
at android.view.View.layout(View.java:17523)
at android.view.ViewGroup.layout(ViewGroup.java:5612)
at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:2342)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2069)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1246)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6301)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:871)
at android.view.Choreographer.doCallbacks(Choreographer.java:683)
at android.view.Choreographer.doFrame(Choreographer.java:619)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:857)
at android.os.Handler.handleCallback(Handler.java:751)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6077)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:866)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:756)
我已经查看了有关 CastException 的文档，但我无法找出错误的来源。请帮忙。提前致谢。
问题在这里
View cartTotalView = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.cart_total_amount_layout, viewGroup, false);
return new CartItemViewHolder(cartTotalView); // Returning wrong ViewHolder it should be CartTotalAmountViewHolder
我正在尝试开发我的第一个 android 应用程序，但遇到以下错误 - 'java.lang.ClassCastException。这是我的 java 代码：
package com.example.fresh24;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;
import java.util.List;
public class CartAdapter extends RecyclerView.Adapter {
private List<CartItemModel> cartItemModelList;
public CartAdapter(List<CartItemModel> cartItemModelList) {
this.cartItemModelList = cartItemModelList;
}
@Override
public int getItemViewType(int position) {
switch (cartItemModelList.get(position).getType()) {
case 0:
return CartItemModel.CART_ITEM;
case 1:
return CartItemModel.TOTAL_AMOUNT;
default:
return -1;
}
}
@NonNull
@Override
public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int viewType) {
switch (viewType) {
case CartItemModel.CART_ITEM:
View cartItemView = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.cart_item_layout, viewGroup, false);
return new CartItemViewHolder(cartItemView);
case CartItemModel.TOTAL_AMOUNT:
View cartTotalView = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.cart_total_amount_layout, viewGroup, false);
return new CartItemViewHolder(cartTotalView);
default:
return null;
}
}
@Override
public void onBindViewHolder(@NonNull RecyclerView.ViewHolder viewHolder, int position) {
switch (cartItemModelList.get(position).getType()) {
case CartItemModel.CART_ITEM:
int resource = cartItemModelList.get(position).getProductImage();
String title = cartItemModelList.get(position).getProducTitle();
int freeCoupons = cartItemModelList.get(position).getFreeCoupons();
String productPrice = cartItemModelList.get(position).getProductPrice();
String cutPrice = cartItemModelList.get(position).getCutPrice();
int offersApplied = cartItemModelList.get(position).getOffersApplied();
((CartItemViewHolder)viewHolder).setItemDetails(resource,title,freeCoupons,productPrice,cutPrice,offersApplied);
break;
case CartItemModel.TOTAL_AMOUNT:
String totalItems = cartItemModelList.get(position).getTotalItems();
String totalItemsPrice = cartItemModelList.get(position).getTotalItemPrice();
String conveniencePrice = cartItemModelList.get(position).getConveniencePrice();
String totalAmount = cartItemModelList.get(position).getTotalAmount();
String savedAmount = cartItemModelList.get(position).getSavedAmount();
((CartTotalAmountViewHolder)viewHolder).setTotalAmount(totalItems,totalItemsPrice,conveniencePrice,totalAmount,savedAmount);
break;
default:
return;
}
}
@Override
public int getItemCount() {
return cartItemModelList.size();
}
class CartItemViewHolder extends RecyclerView.ViewHolder {
private ImageView productImage;
private ImageView freecouponIcon;
private TextView productTitle;
private TextView freeCoupons;
private TextView productPrice;
private TextView productCutPrice;
private TextView offersApplied;
/*private TextView couponsApplied;
private TextView productQuantity;*/
public CartItemViewHolder(@NonNull View itemView) {
super(itemView);
productImage = itemView.findViewById(R.id.product_image);
productTitle = itemView.findViewById(R.id.product_title);
freecouponIcon = itemView.findViewById(R.id.free_coupon_icon);
freeCoupons = itemView.findViewById(R.id.tv_free_coupon);
productPrice = itemView.findViewById(R.id.product_price);
productCutPrice = itemView.findViewById(R.id.cut_price);
offersApplied = itemView.findViewById(R.id.offers_applied);
}
private void setItemDetails(int resource, String title, int freeCouponsNo, String productPriceText, String productCutPriceText, int offersAppliedNo) {
productImage.setImageResource(resource);
productTitle.setText(title);
if (freeCouponsNo > 0) {
freecouponIcon.setVisibility(View.VISIBLE);
freeCoupons.setVisibility(View.VISIBLE);
if (freeCouponsNo == 1) {
freeCoupons.setText("free " + freeCouponsNo + " Coupon");
} else {
freeCoupons.setText("free " + freeCouponsNo + " Coupons");
}
} else {
freecouponIcon.setVisibility(View.INVISIBLE);
freeCoupons.setVisibility(View.INVISIBLE);
}
productPrice.setText(productPriceText);
productCutPrice.setText(productCutPriceText);
if (offersAppliedNo > 0) {
offersApplied.setVisibility(View.VISIBLE);
offersApplied.setText(offersAppliedNo + "Offers Applied");
} else {
offersApplied.setVisibility(View.INVISIBLE);
}
}
}
class CartTotalAmountViewHolder extends RecyclerView.ViewHolder {
private TextView totalItems;
private TextView totalItemPrice;
private TextView conveniencePrice;
private TextView totalAmount;
private TextView savedAmount;
public CartTotalAmountViewHolder(@NonNull View itemView) {
super(itemView);
totalItems = itemView.findViewById(R.id.total_items);
totalItemPrice = itemView.findViewById(R.id.total_items_price);
conveniencePrice = itemView.findViewById(R.id.convenience_price);
totalAmount = itemView.findViewById(R.id.total_price);
savedAmount = itemView.findViewById(R.id.saved_amount);
}
private void setTotalAmount(String totalItemText, String totalItemPriceText, String conveniencePriceText, String totalAmountText, String savedAmountText) {
totalItems.setText(totalItemText);
totalItemPrice.setText(totalItemPriceText);
conveniencePrice.setText(conveniencePriceText);
totalAmount.setText(totalAmountText);
savedAmount.setText(savedAmountText);
}
}
}
这里是完整的堆栈跟踪：
2019-08-01 09:51:45.298 26950-26950/com.example.fresh24 E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.fresh24, PID: 26950
java.lang.ClassCastException: com.example.fresh24.CartAdapter$CartItemViewHolder cannot be cast to com.example.fresh24.CartAdapter$CartTotalAmountViewHolder
at com.example.fresh24.CartAdapter.onBindViewHolder(CartAdapter.java:67)
at androidx.recyclerview.widget.RecyclerView$Adapter.onBindViewHolder(RecyclerView.java:6781)
at androidx.recyclerview.widget.RecyclerView$Adapter.bindViewHolder(RecyclerView.java:6823)
at androidx.recyclerview.widget.RecyclerView$Recycler.tryBindViewHolderByDeadline(RecyclerView.java:5752)
at androidx.recyclerview.widget.RecyclerView$Recycler.tryGetViewHolderForPositionByDeadline(RecyclerView.java:6019)
at androidx.recyclerview.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5858)
at androidx.recyclerview.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5854)
at androidx.recyclerview.widget.LinearLayoutManager$LayoutState.next(LinearLayoutManager.java:2230)
at androidx.recyclerview.widget.LinearLayoutManager.layoutChunk(LinearLayoutManager.java:1557)
at androidx.recyclerview.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1517)
at androidx.recyclerview.widget.LinearLayoutManager.onLayoutChildren(LinearLayoutManager.java:612)
at androidx.recyclerview.widget.RecyclerView.dispatchLayoutStep2(RecyclerView.java:3924)
at androidx.recyclerview.widget.RecyclerView.dispatchLayout(RecyclerView.java:3641)
at androidx.recyclerview.widget.RecyclerView.onLayout(RecyclerView.java:4194)
at android.view.View.layout(View.java:17523)
at android.view.ViewGroup.layout(ViewGroup.java:5612)
at androidx.constraintlayout.widget.ConstraintLayout.onLayout(ConstraintLayout.java:1915)
at android.view.View.layout(View.java:17523)
at android.view.ViewGroup.layout(ViewGroup.java:5612)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:323)
at android.widget.FrameLayout.onLayout(FrameLayout.java:261)
at android.view.View.layout(View.java:17523)
at android.view.ViewGroup.layout(ViewGroup.java:5612)
at com.google.android.material.appbar.HeaderScrollingViewBehavior.layoutChild(HeaderScrollingViewBehavior.java:142)
at com.google.android.material.appbar.ViewOffsetBehavior.onLayoutChild(ViewOffsetBehavior.java:41)
at com.google.android.material.appbar.AppBarLayout$ScrollingViewBehavior.onLayoutChild(AppBarLayout.java:1556)
at androidx.coordinatorlayout.widget.CoordinatorLayout.onLayout(CoordinatorLayout.java:888)
at android.view.View.layout(View.java:17523)
at android.view.ViewGroup.layout(ViewGroup.java:5612)
at androidx.drawerlayout.widget.DrawerLayout.onLayout(DrawerLayout.java:1231)
at android.view.View.layout(View.java:17523)
at android.view.ViewGroup.layout(ViewGroup.java:5612)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:323)
at android.widget.FrameLayout.onLayout(FrameLayout.java:261)
at android.view.View.layout(View.java:17523)
at android.view.ViewGroup.layout(ViewGroup.java:5612)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1741)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1585)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1494)
at android.view.View.layout(View.java:17523)
at android.view.ViewGroup.layout(ViewGroup.java:5612)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:323)
at android.widget.FrameLayout.onLayout(FrameLayout.java:261)
at android.view.View.layout(View.java:17523)
at android.view.ViewGroup.layout(ViewGroup.java:5612)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1741)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1585)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1494)
at android.view.View.layout(View.java:17523)
at android.view.ViewGroup.layout(ViewGroup.java:5612)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:323)
at android.widget.FrameLayout.onLayout(FrameLayout.java:261)
2019-08-01 09:51:45.298 26950-26950/com.example.fresh24 E/AndroidRuntime: at com.android.internal.policy.DecorView.onLayout(DecorView.java:724)
at android.view.View.layout(View.java:17523)
at android.view.ViewGroup.layout(ViewGroup.java:5612)
at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:2342)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2069)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1246)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6301)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:871)
at android.view.Choreographer.doCallbacks(Choreographer.java:683)
at android.view.Choreographer.doFrame(Choreographer.java:619)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:857)
at android.os.Handler.handleCallback(Handler.java:751)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6077)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:866)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:756)
我已经查看了有关 CastException 的文档，但我无法找出错误的来源。请帮忙。提前致谢。
问题在这里
View cartTotalView = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.cart_total_amount_layout, viewGroup, false);
return new CartItemViewHolder(cartTotalView); // Returning wrong ViewHolder it should be CartTotalAmountViewHolder