未在片段中获取 Activity 的上下文
Not Getting Activity's context in fragment
我正在开发一个包含购物车管理的电子商务应用程序。现在我有一个片段（CartFragment）和一个适配器（ShowCartAdapter）附加到 recyclerView。
我在单个片段中进行了三个网络调用（即 1. 将商品添加到购物车，2. 显示购物车中的商品，3. 删除购物车中的商品）。
以上片段附加到 activity(ProductDetailActivity)。将商品添加到购物车并在购物车中显示商品效果很好，但第三个，即从购物车中删除商品很麻烦 me.I我的 cardview 中的一个图标用于删除一个项目，单击该图标我想从 recyclerview 中删除该项目，现在我将项目的唯一 ID 从适配器发送到片段，但它给了我 null当我点击 icon.Might 时 ProgressDialog(progressDialog=new ProgressDialog(getActivity());) 上的指针是 activity 不再附加到该片段。下面是我的适配器、片段和 activity.Please 帮助我的代码片段 !!!
CartFragment
public class CartFragment extends Fragment implements RetrofitTaskListener<AddCart> {
private ProgressDialog progressDialog;
private RecyclerView recyclerView;
private AdapterAddCart adapter;
private AdapterShowCart adapterShowCart;
private boolean loading = true;
AddCart addCartList;
int pageIndex;
private LinearLayoutManager linearLayoutManager;
private String email1,articlCode,image,quantity,cost;
private static final String STARTING_TEXT = "Four Buttons Bottom Navigation";
private Button btnCheckout;
private FragmentTransaction fragmentTransaction;
private int frag,cartSize;
private TextView cartEmptyTxt;
private Context context;
private SharedPreferences sharedPreference;
private SharedPreferences.Editor editor;
private SessionManager session;
private EditText cmntTxt;
public CartFragment() {
// Required empty public constructor
}
public static CartFragment newInstance(int text) {
Bundle args = new Bundle();
args.putInt(STARTING_TEXT, text);
CartFragment sampleFragment = new CartFragment();
sampleFragment.setArguments(args);
return sampleFragment;
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
articlCode = getArguments().getString("artCode");
image = getArguments().getString("image");
quantity = getArguments().getString("quantity");
cost = getArguments().getString("cost");
frag = getArguments().getInt("fragment");
View view = inflater.inflate(R.layout.fragment_cart, container, false);
cmntTxt = (EditText)view.findViewById(R.id.comment_txt);
getActivity().getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN);
session = new SessionManager(getActivity().getApplicationContext());
sharedPreference = getActivity().getSharedPreferences("CART",0);
editor = sharedPreference.edit();
((AppCompatActivity) getActivity()).getSupportActionBar().setTitle("Cart");
btnCheckout = (Button)view.findViewById(R.id.btnCheckout);
cartEmptyTxt = (TextView)view.findViewById(R.id.emptytxt);
cartEmptyTxt.setVisibility(View.GONE);
if (!session.isLoggedIn()) {
cartEmptyTxt.setVisibility(View.VISIBLE);
btnCheckout.setVisibility(View.GONE);
cmntTxt.setVisibility(View.GONE);
}
btnCheckout.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
FragmentManager fm = getFragmentManager();
fragmentTransaction = fm.beginTransaction();
AddressFragment addressFragment = new AddressFragment();
fragmentTransaction.replace(R.id.fragmentContainer,addressFragment);
fragmentTransaction.addToBackStack(null);
fragmentTransaction.commit(); }
});
pageIndex = 0;
recyclerView = (RecyclerView)view.findViewById(R.id.cart_recycler_view);
linearLayoutManager=new LinearLayoutManager(getActivity());
recyclerView.setLayoutManager(linearLayoutManager);
SQLiteHandler sqLiteHandler = new SQLiteHandler(getActivity());
List<SessionModel> sessionModelList = sqLiteHandler.getUserDetails();
Bundle arguments = getArguments();
if (arguments != null) {
for (SessionModel sm : sessionModelList){
email1 = sm.getEmail();
}
if (frag == 6){
callCartService(email1,articlCode,cost,quantity);
}else if (email1!=null){
callGetCart(email1);
}
}
return view;
}
public void callCartService(String email,String artCode,String price,String qty){
showProgreass();
pageIndex = pageIndex + 1;
String url = String.format(ServerConfigStage.ADD_CART(),email,artCode,price,qty);
RetrofitTask task = new RetrofitTask<>(CartFragment.this, CommonUtility.HTTP_REQUEST_TYPE.POST, CommonUtility.CallerFunction.ADD_CART_FUNCTION, url,getActivity());
task.execute();
}
public void callGetCart(String email){
showProgreass();
pageIndex = pageIndex + 1;
String url = String.format(ServerConfigStage.GET_CART(),email);
RetrofitTask task = new RetrofitTask<>(CartFragment.this, CommonUtility.HTTP_REQUEST_TYPE.POST, CommonUtility.CallerFunction.GET_CART, url,getActivity());
task.execute();
}
public void delItemCart(String email,String itemId){
adapterShowCart = new AdapterShowCart(getContext(),CartFragment.this);
showProgreass();
String url = String.format(ServerConfigStage.DEL_ITEM_CART(),email,itemId);
RetrofitTask task = new RetrofitTask<>(CartFragment.this, CommonUtility.HTTP_REQUEST_TYPE.POST, CommonUtility.CallerFunction.DEL_ITEM_CART, url,getActivity());
task.execute();
}
public void showProgreass(){
progressDialog=new ProgressDialog(getActivity());
progressDialog.setIndeterminate(true);
progressDialog.setMessage("Please Wait...");
progressDialog.setCanceledOnTouchOutside(false);
progressDialog.setCancelable(false);
progressDialog.show();
}
public void stopProgress(){
if(progressDialog!=null && progressDialog.isShowing())
progressDialog.cancel();
}
@Override
public void onRetrofitTaskComplete(Response<AddCart> response, Context context, CommonUtility.CallerFunction _callerFunction) {
stopProgress();
if (response.isSuccess()) {
if (response.body() != null) {
addCartList =response.body();
if (_callerFunction == CommonUtility.CallerFunction.ADD_CART_FUNCTION){
if (addCartList.getStatus() == 0){
cartSize = addCartList.getDeatils().size();
editor.putInt("CART_ITEMS",cartSize);
editor.commit();
Toast.makeText(context, addCartList.getResponse(), Toast.LENGTH_SHORT).show();
if (adapter == null) {
adapter = new AdapterAddCart(context, R.layout.row_cart, addCartList);
recyclerView.setAdapter(adapter);
}
}else
if(addCartList.getStatus()>0) {
cartSize = addCartList.getDeatils().size();
editor.putInt("CART_ITEMS",cartSize);
editor.commit();
if (adapter == null) {
adapter = new AdapterAddCart(context, R.layout.row_cart, addCartList);
recyclerView.setAdapter(adapter);
}
adapter.notifyDataSetChanged();
}else {cartSize = addCartList.getDeatils().size();
editor.putInt("CART_ITEMS",cartSize);
editor.commit();
if (adapter == null) {
adapter = new AdapterAddCart(context, R.layout.row_cart, addCartList);
recyclerView.setAdapter( adapter );;
}
adapter.notifyDataSetChanged();
Toast.makeText(context, addCartList.getResponse(), Toast.LENGTH_SHORT).show();
}
}else if (_callerFunction == CommonUtility.CallerFunction.GET_CART){
if (addCartList.getStatus() == 0){
if (addCartList.getCart().size()>0){
cartSize = addCartList.getCart().size();
editor.putInt("CART_ITEMS",cartSize);
editor.commit();
}
}else
if(addCartList.getStatus()>0) {
if (addCartList.getCart().size()>0){
cartSize = addCartList.getCart().size();
editor.putInt("CART_ITEMS",cartSize);
editor.commit();}
if (adapterShowCart == null) {
adapterShowCart = new AdapterShowCart(context, R.layout.row_cart, addCartList);
recyclerView.setAdapter(adapterShowCart);
;
}
adapterShowCart.notifyDataSetChanged();
}else {
cartEmptyTxt.setVisibility(View.VISIBLE);
}
//Toast.makeText(context, addCartList.getResponse(), Toast.LENGTH_SHORT).show();
}else if (_callerFunction == CommonUtility.CallerFunction.DEL_ITEM_CART){
if (addCartList.getStatus()>0){
if (adapterShowCart == null) {
adapterShowCart = new AdapterShowCart(context, R.layout.row_cart, addCartList);
recyclerView.setAdapter(adapterShowCart);
}adapterShowCart.notifyDataSetChanged();
}
}
}
}
}
@Override
public void onRetrofitTaskFailure(Throwable t) {
stopProgress();
// Toast.makeText(getActivity(),"Fail to load Data",Toast.LENGTH_LONG).show();
if (getActivity()!= null)
{
getActivity().finish();
}
}
public void myFragmentMethod(){
// make sure to double check casts (to YourActivity) like these before invoking
((ProductDetailActivity)getActivity()).myOnResume();
}
}
AdapterShowCart
public class AdapterShowCart extends RecyclerView.Adapter<AdapterShowCart.ViewHolder>{
private AddCart addCartList;
private RemoveItemCommunication removeItemCommunication;
private CartFragment cartFragment = new CartFragment();
Context context;
private int layoutResourceId,cart;
private SharedPreferences sharedPreferences;
public AdapterShowCart(Context context, int layoutResourceId, AddCart addCarts) {
this.context = context;
this.layoutResourceId = layoutResourceId;
this.addCartList = addCarts;
}
public AdapterShowCart(Context context, CartFragment cartFragment) {
this.context = context;
this.cartFragment=cartFragment;
}
public void setOnClickListener(RemoveItemCommunication removeItemCommunication1){
removeItemCommunication = removeItemCommunication1;
}
@Override
public AdapterShowCart.ViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.row_cart, viewGroup, false);
return new ViewHolder(view);
}
@Override
public void onBindViewHolder(AdapterShowCart.ViewHolder viewHolder, int i) {
viewHolder.tv_android.setText("Price :"+" "+addCartList.getCart().get(i).getPrice());
viewHolder.tv_art_number.setText("Article No. :"+" "+addCartList.getCart().get(i).getItemCode());
viewHolder.tvQty.setText("Quantity :"+""+addCartList.getCart().get(i).getCartQuantity());
//viewHolder.img_android.setImageResource(products.get(i).getAndroid_image_url());
Picasso.with(context).load(addCartList.getCart().get(i).getURL()).resize(240, 120).into(viewHolder.img_android);
}
@Override
public int getItemCount() {
// cart = sharedPreferences.getInt("CART_ITEMS",0);
return addCartList.getCart().size();
}
class ViewHolder extends RecyclerView.ViewHolder{
private TextView tv_android,tv_art_number,tvQty;
private ImageView img_android,remove;
private int pos;
private CardView cardView;
public ViewHolder(View view) {
super(view);
tv_android = (TextView)view.findViewById(R.id.tvTitle);
tv_art_number=(TextView)view.findViewById(R.id.tvNumber);
cardView = (CardView)view.findViewById(R.id.card_view);
img_android = (ImageView) view.findViewById(R.id.mealImage);
tvQty=(TextView)view.findViewById(R.id.tvQty);
remove=(ImageView)view.findViewById(R.id.removeItem);
remove.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
int pos = getAdapterPosition();
cartFragment.delItemCart(addCartList.getEmail(),addCartList.getCart().get(pos).getId());
}
});
cardView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
pos = getAdapterPosition();
}
});
}
}
}
ProductDetailActivity
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_product_detail);
this.getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN);
toolbar = (Toolbar) findViewById(R.id.tool_bar);
setSupportActionBar(toolbar);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
getSupportActionBar().setDisplayShowHomeEnabled(true);
getSupportActionBar().setTitle("Product Details");
supportInvalidateOptionsMenu();
toolbar.setTitleTextColor(Color.WHITE);
session = new SessionManager(getApplicationContext());
itemCode = getIntent().getExtras().getString("ItemCode");
itemName = getIntent().getExtras().getString("ItemName");
stockAvailibility = (ImageView) findViewById(R.id.stock_image);
code = (TextView) findViewById(R.id.item_code);
price = (TextView) findViewById(R.id.price_txt);
name = (TextView) findViewById(R.id.product_name);
productImage = (ImageView) findViewById(R.id.image_big);
stock = (TextView) findViewById(R.id.stock);
stock_status = (TextView) findViewById(R.id.stock_text);
quantity_txt = (EditText) findViewById(R.id.unit_number);
qtyText = (TextView) findViewById(R.id.selectQty);
addCart = (Button) findViewById(R.id.btn_add_cart);
callProductDetail(itemCode);
addCart.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
String selectedQty = quantity_txt.getText().toString();
if (session.isLoggedIn()) {
if (!selectedQty.isEmpty() && Integer.parseInt(selectedQty) > Integer.parseInt(qty)) {
AlertDialog.Builder builder = new AlertDialog.Builder(ProductDetailActivity.this);
builder.setMessage("You can not add more than" + " " + qty + " " + "units")
.setCancelable(false)
.setPositiveButton("OK", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
//do things
}
});
AlertDialog alert = builder.create();
alert.show();
} else if (selectedQty.isEmpty() || Integer.parseInt(selectedQty) == 0) {
AlertDialog.Builder builder = new AlertDialog.Builder(ProductDetailActivity.this);
builder.setMessage("Please Add Quantity")
.setCancelable(false)
.setPositiveButton("OK", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
//do things
}
});
AlertDialog alert = builder.create();
alert.show();
} else if (!selectedQty.isEmpty() && Integer.parseInt(selectedQty) != 0 && Integer.parseInt(selectedQty) <= Integer.parseInt(qty)) {
addCart.setVisibility(View.GONE);
hideKeyboard(ProductDetailActivity.this);
fm = getSupportFragmentManager();
fragmentTransaction = fm.beginTransaction();
CartFragment cartFragment = new CartFragment();
fragmentTransaction.replace(R.id.fragmentContainer,cartFragment);
Bundle bundle = new Bundle();
bundle.putString("artCode", artCode);
bundle.putString("image",image_url);
bundle.putString("quantity",selectedQty);
bundle.putString("cost",cost);
bundle.putInt("fragment",6);
cartFragment.setArguments(bundle);
fragmentTransaction.addToBackStack(null);
fragmentTransaction.commitAllowingStateLoss();
}
} else {
AlertDialog.Builder builder = new AlertDialog.Builder(ProductDetailActivity.this);
builder.setMessage("Please Login To Continue")
.setCancelable(false)
.setNegativeButton("NOT NOW", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
}
})
.setPositiveButton("LOGIN", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
Intent intent = new Intent(ProductDetailActivity.this, LoginActivity.class);
intent.putExtra("fragment", 7);
startActivity(intent);
}
});
AlertDialog alert = builder.create();
alert.show();
}
}
});
}
public void myOnResume(){
this.onResume();
addCart.setVisibility(View.VISIBLE);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
// todo: goto back activity from here
finish();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
public void showProgreass() {
progressDialog = new ProgressDialog(ProductDetailActivity.this);
progressDialog.setIndeterminate(true);
progressDialog.setMessage("Please Wait...");
progressDialog.setCanceledOnTouchOutside(false);
progressDialog.setCancelable(false);
progressDialog.show();
}
public void stopProgress() {
if (progressDialog != null && progressDialog.isShowing())
progressDialog.cancel();
}
public void callProductDetail(String productId) {
showProgreass();
String url = String.format(ServerConfigStage.GET_PRODUCT_DETAIL(), productId);
RetrofitTask task = new RetrofitTask<List<ProductDetail>>(ProductDetailActivity.this, CommonUtility.HTTP_REQUEST_TYPE.GET, CommonUtility.CallerFunction.GET_PRODUCT_DETAIL, url, ProductDetailActivity.this);
task.execute();
}
@Override
public void onRetrofitTaskComplete(Response<List<ProductDetail>> response, Context context, CommonUtility.CallerFunction _callerFunction) {
stopProgress();
if (response.isSuccess()) {
if (response.body() != null) {
if (response.body().get(0).getStatus() > 0) {
String json = gson.toJson(response);
System.out.println(json);
artCode = response.body().get(0).getItemcode();
cost = response.body().get(0).getPrice();
String desc = response.body().get(0).getDescription();
image_url = response.body().get(0).getURL();
Double d = response.body().get(0).getStock();
Double aDouble = new Double(d);
int i = aDouble.intValue();
qty = String.valueOf(i);
if (qty.equals("0")) {
stock_status.setText("Not In Stock");
stockAvailibility.setImageResource(R.mipmap.stockunavailable);
quantity_txt.setVisibility(View.GONE);
qtyText.setVisibility(View.GONE);
addCart.setVisibility(View.GONE);
} else {
stockAvailibility.setImageResource(R.mipmap.stock_image);
}
code.setText(artCode);
price.setText("Euro" + "" + cost);
productDescription = (ExpandableTextView) findViewById(R.id.expand_text_view);
productDescription.setText(desc);
name.setText(itemName);
stock.setText("Units :" + " " + qty);
Picasso.with(context).load(image_url).resize(240, 120).into(productImage);
} else {
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setMessage(response.body().get(0).getResponse())
.setCancelable(false)
.setPositiveButton("OK", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
//do things
}
});
AlertDialog alert = builder.create();
alert.show();
//Toast.makeText(context, response.body().get(0).getResponse(), Toast.LENGTH_SHORT).show();
}
}
}
}
@Override
public void onRetrofitTaskFailure(Throwable t) {
stopProgress();
//Toast.makeText(ProductDetailActivity.this,"Fail to load Data",Toast.LENGTH_LONG).show();
finish();
}
public static void hideKeyboard(Context ctx) {
InputMethodManager inputManager = (InputMethodManager) ctx
.getSystemService(Context.INPUT_METHOD_SERVICE);
// check if no view has focus:
View v = ((Activity) ctx).getCurrentFocus();
if (v == null)
return;
inputManager.hideSoftInputFromWindow(v.getWindowToken(), 0);
}
}
堆栈跟踪
Process: com.jbm.jbmcustomer, PID: 9188
java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.res.Resources$Theme android.content.Context.getTheme()' on a null object reference
at android.app.AlertDialog.resolveDialogTheme(AlertDialog.java:222)
at android.app.AlertDialog.<init>(AlertDialog.java:200)
at android.app.AlertDialog.<init>(AlertDialog.java:196)
at android.app.AlertDialog.<init>(AlertDialog.java:141)
at android.app.ProgressDialog.<init>(ProgressDialog.java:77)
at com.jbm.jbmcustomer.fragment.CartFragment.showProgreass(CartFragment.java:179)
at com.jbm.jbmcustomer.fragment.CartFragment.delItemCart(CartFragment.java:172)
at com.jbm.jbmcustomer.adapter.AdapterShowCart.onClick(AdapterShowCart.java:80)
at android.view.View.performClick(View.java:5198)
at android.view.View$PerformClick.run(View.java:21147)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
getActivity 返回 null 的原因是，您使用的是在适配器 class 内初始化的购物车片段实例，该实例未附加到任何 activity。
因此，请将 CartFragment 的实例从 CartFragment 传递到适配器 class 以解决问题。 AdapterShowCart class 中有一个构造函数，其中传递了购物车片段实例，但在片段中的 delItemCart(String email,String itemId) 中调用了它（我不明白为什么要这样做）。
在 AdapterShowCart 第 80 行中，您正在触发一个操作，该操作尝试使用对不再存在的上下文的引用从资源中获取值。
据推测，ProductDetailActivity.this 导致了问题。
我正在开发一个包含购物车管理的电子商务应用程序。现在我有一个片段（CartFragment）和一个适配器（ShowCartAdapter）附加到 recyclerView。
我在单个片段中进行了三个网络调用（即 1. 将商品添加到购物车，2. 显示购物车中的商品，3. 删除购物车中的商品）。
以上片段附加到 activity(ProductDetailActivity)。将商品添加到购物车并在购物车中显示商品效果很好，但第三个，即从购物车中删除商品很麻烦 me.I我的 cardview 中的一个图标用于删除一个项目，单击该图标我想从 recyclerview 中删除该项目，现在我将项目的唯一 ID 从适配器发送到片段，但它给了我 null当我点击 icon.Might 时 ProgressDialog(progressDialog=new ProgressDialog(getActivity());) 上的指针是 activity 不再附加到该片段。下面是我的适配器、片段和 activity.Please 帮助我的代码片段 !!!
CartFragment
public class CartFragment extends Fragment implements RetrofitTaskListener<AddCart> {
private ProgressDialog progressDialog;
private RecyclerView recyclerView;
private AdapterAddCart adapter;
private AdapterShowCart adapterShowCart;
private boolean loading = true;
AddCart addCartList;
int pageIndex;
private LinearLayoutManager linearLayoutManager;
private String email1,articlCode,image,quantity,cost;
private static final String STARTING_TEXT = "Four Buttons Bottom Navigation";
private Button btnCheckout;
private FragmentTransaction fragmentTransaction;
private int frag,cartSize;
private TextView cartEmptyTxt;
private Context context;
private SharedPreferences sharedPreference;
private SharedPreferences.Editor editor;
private SessionManager session;
private EditText cmntTxt;
public CartFragment() {
// Required empty public constructor
}
public static CartFragment newInstance(int text) {
Bundle args = new Bundle();
args.putInt(STARTING_TEXT, text);
CartFragment sampleFragment = new CartFragment();
sampleFragment.setArguments(args);
return sampleFragment;
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
articlCode = getArguments().getString("artCode");
image = getArguments().getString("image");
quantity = getArguments().getString("quantity");
cost = getArguments().getString("cost");
frag = getArguments().getInt("fragment");
View view = inflater.inflate(R.layout.fragment_cart, container, false);
cmntTxt = (EditText)view.findViewById(R.id.comment_txt);
getActivity().getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN);
session = new SessionManager(getActivity().getApplicationContext());
sharedPreference = getActivity().getSharedPreferences("CART",0);
editor = sharedPreference.edit();
((AppCompatActivity) getActivity()).getSupportActionBar().setTitle("Cart");
btnCheckout = (Button)view.findViewById(R.id.btnCheckout);
cartEmptyTxt = (TextView)view.findViewById(R.id.emptytxt);
cartEmptyTxt.setVisibility(View.GONE);
if (!session.isLoggedIn()) {
cartEmptyTxt.setVisibility(View.VISIBLE);
btnCheckout.setVisibility(View.GONE);
cmntTxt.setVisibility(View.GONE);
}
btnCheckout.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
FragmentManager fm = getFragmentManager();
fragmentTransaction = fm.beginTransaction();
AddressFragment addressFragment = new AddressFragment();
fragmentTransaction.replace(R.id.fragmentContainer,addressFragment);
fragmentTransaction.addToBackStack(null);
fragmentTransaction.commit(); }
});
pageIndex = 0;
recyclerView = (RecyclerView)view.findViewById(R.id.cart_recycler_view);
linearLayoutManager=new LinearLayoutManager(getActivity());
recyclerView.setLayoutManager(linearLayoutManager);
SQLiteHandler sqLiteHandler = new SQLiteHandler(getActivity());
List<SessionModel> sessionModelList = sqLiteHandler.getUserDetails();
Bundle arguments = getArguments();
if (arguments != null) {
for (SessionModel sm : sessionModelList){
email1 = sm.getEmail();
}
if (frag == 6){
callCartService(email1,articlCode,cost,quantity);
}else if (email1!=null){
callGetCart(email1);
}
}
return view;
}
public void callCartService(String email,String artCode,String price,String qty){
showProgreass();
pageIndex = pageIndex + 1;
String url = String.format(ServerConfigStage.ADD_CART(),email,artCode,price,qty);
RetrofitTask task = new RetrofitTask<>(CartFragment.this, CommonUtility.HTTP_REQUEST_TYPE.POST, CommonUtility.CallerFunction.ADD_CART_FUNCTION, url,getActivity());
task.execute();
}
public void callGetCart(String email){
showProgreass();
pageIndex = pageIndex + 1;
String url = String.format(ServerConfigStage.GET_CART(),email);
RetrofitTask task = new RetrofitTask<>(CartFragment.this, CommonUtility.HTTP_REQUEST_TYPE.POST, CommonUtility.CallerFunction.GET_CART, url,getActivity());
task.execute();
}
public void delItemCart(String email,String itemId){
adapterShowCart = new AdapterShowCart(getContext(),CartFragment.this);
showProgreass();
String url = String.format(ServerConfigStage.DEL_ITEM_CART(),email,itemId);
RetrofitTask task = new RetrofitTask<>(CartFragment.this, CommonUtility.HTTP_REQUEST_TYPE.POST, CommonUtility.CallerFunction.DEL_ITEM_CART, url,getActivity());
task.execute();
}
public void showProgreass(){
progressDialog=new ProgressDialog(getActivity());
progressDialog.setIndeterminate(true);
progressDialog.setMessage("Please Wait...");
progressDialog.setCanceledOnTouchOutside(false);
progressDialog.setCancelable(false);
progressDialog.show();
}
public void stopProgress(){
if(progressDialog!=null && progressDialog.isShowing())
progressDialog.cancel();
}
@Override
public void onRetrofitTaskComplete(Response<AddCart> response, Context context, CommonUtility.CallerFunction _callerFunction) {
stopProgress();
if (response.isSuccess()) {
if (response.body() != null) {
addCartList =response.body();
if (_callerFunction == CommonUtility.CallerFunction.ADD_CART_FUNCTION){
if (addCartList.getStatus() == 0){
cartSize = addCartList.getDeatils().size();
editor.putInt("CART_ITEMS",cartSize);
editor.commit();
Toast.makeText(context, addCartList.getResponse(), Toast.LENGTH_SHORT).show();
if (adapter == null) {
adapter = new AdapterAddCart(context, R.layout.row_cart, addCartList);
recyclerView.setAdapter(adapter);
}
}else
if(addCartList.getStatus()>0) {
cartSize = addCartList.getDeatils().size();
editor.putInt("CART_ITEMS",cartSize);
editor.commit();
if (adapter == null) {
adapter = new AdapterAddCart(context, R.layout.row_cart, addCartList);
recyclerView.setAdapter(adapter);
}
adapter.notifyDataSetChanged();
}else {cartSize = addCartList.getDeatils().size();
editor.putInt("CART_ITEMS",cartSize);
editor.commit();
if (adapter == null) {
adapter = new AdapterAddCart(context, R.layout.row_cart, addCartList);
recyclerView.setAdapter( adapter );;
}
adapter.notifyDataSetChanged();
Toast.makeText(context, addCartList.getResponse(), Toast.LENGTH_SHORT).show();
}
}else if (_callerFunction == CommonUtility.CallerFunction.GET_CART){
if (addCartList.getStatus() == 0){
if (addCartList.getCart().size()>0){
cartSize = addCartList.getCart().size();
editor.putInt("CART_ITEMS",cartSize);
editor.commit();
}
}else
if(addCartList.getStatus()>0) {
if (addCartList.getCart().size()>0){
cartSize = addCartList.getCart().size();
editor.putInt("CART_ITEMS",cartSize);
editor.commit();}
if (adapterShowCart == null) {
adapterShowCart = new AdapterShowCart(context, R.layout.row_cart, addCartList);
recyclerView.setAdapter(adapterShowCart);
;
}
adapterShowCart.notifyDataSetChanged();
}else {
cartEmptyTxt.setVisibility(View.VISIBLE);
}
//Toast.makeText(context, addCartList.getResponse(), Toast.LENGTH_SHORT).show();
}else if (_callerFunction == CommonUtility.CallerFunction.DEL_ITEM_CART){
if (addCartList.getStatus()>0){
if (adapterShowCart == null) {
adapterShowCart = new AdapterShowCart(context, R.layout.row_cart, addCartList);
recyclerView.setAdapter(adapterShowCart);
}adapterShowCart.notifyDataSetChanged();
}
}
}
}
}
@Override
public void onRetrofitTaskFailure(Throwable t) {
stopProgress();
// Toast.makeText(getActivity(),"Fail to load Data",Toast.LENGTH_LONG).show();
if (getActivity()!= null)
{
getActivity().finish();
}
}
public void myFragmentMethod(){
// make sure to double check casts (to YourActivity) like these before invoking
((ProductDetailActivity)getActivity()).myOnResume();
}
}
AdapterShowCart
public class AdapterShowCart extends RecyclerView.Adapter<AdapterShowCart.ViewHolder>{
private AddCart addCartList;
private RemoveItemCommunication removeItemCommunication;
private CartFragment cartFragment = new CartFragment();
Context context;
private int layoutResourceId,cart;
private SharedPreferences sharedPreferences;
public AdapterShowCart(Context context, int layoutResourceId, AddCart addCarts) {
this.context = context;
this.layoutResourceId = layoutResourceId;
this.addCartList = addCarts;
}
public AdapterShowCart(Context context, CartFragment cartFragment) {
this.context = context;
this.cartFragment=cartFragment;
}
public void setOnClickListener(RemoveItemCommunication removeItemCommunication1){
removeItemCommunication = removeItemCommunication1;
}
@Override
public AdapterShowCart.ViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.row_cart, viewGroup, false);
return new ViewHolder(view);
}
@Override
public void onBindViewHolder(AdapterShowCart.ViewHolder viewHolder, int i) {
viewHolder.tv_android.setText("Price :"+" "+addCartList.getCart().get(i).getPrice());
viewHolder.tv_art_number.setText("Article No. :"+" "+addCartList.getCart().get(i).getItemCode());
viewHolder.tvQty.setText("Quantity :"+""+addCartList.getCart().get(i).getCartQuantity());
//viewHolder.img_android.setImageResource(products.get(i).getAndroid_image_url());
Picasso.with(context).load(addCartList.getCart().get(i).getURL()).resize(240, 120).into(viewHolder.img_android);
}
@Override
public int getItemCount() {
// cart = sharedPreferences.getInt("CART_ITEMS",0);
return addCartList.getCart().size();
}
class ViewHolder extends RecyclerView.ViewHolder{
private TextView tv_android,tv_art_number,tvQty;
private ImageView img_android,remove;
private int pos;
private CardView cardView;
public ViewHolder(View view) {
super(view);
tv_android = (TextView)view.findViewById(R.id.tvTitle);
tv_art_number=(TextView)view.findViewById(R.id.tvNumber);
cardView = (CardView)view.findViewById(R.id.card_view);
img_android = (ImageView) view.findViewById(R.id.mealImage);
tvQty=(TextView)view.findViewById(R.id.tvQty);
remove=(ImageView)view.findViewById(R.id.removeItem);
remove.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
int pos = getAdapterPosition();
cartFragment.delItemCart(addCartList.getEmail(),addCartList.getCart().get(pos).getId());
}
});
cardView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
pos = getAdapterPosition();
}
});
}
}
}
ProductDetailActivity
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_product_detail);
this.getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN);
toolbar = (Toolbar) findViewById(R.id.tool_bar);
setSupportActionBar(toolbar);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
getSupportActionBar().setDisplayShowHomeEnabled(true);
getSupportActionBar().setTitle("Product Details");
supportInvalidateOptionsMenu();
toolbar.setTitleTextColor(Color.WHITE);
session = new SessionManager(getApplicationContext());
itemCode = getIntent().getExtras().getString("ItemCode");
itemName = getIntent().getExtras().getString("ItemName");
stockAvailibility = (ImageView) findViewById(R.id.stock_image);
code = (TextView) findViewById(R.id.item_code);
price = (TextView) findViewById(R.id.price_txt);
name = (TextView) findViewById(R.id.product_name);
productImage = (ImageView) findViewById(R.id.image_big);
stock = (TextView) findViewById(R.id.stock);
stock_status = (TextView) findViewById(R.id.stock_text);
quantity_txt = (EditText) findViewById(R.id.unit_number);
qtyText = (TextView) findViewById(R.id.selectQty);
addCart = (Button) findViewById(R.id.btn_add_cart);
callProductDetail(itemCode);
addCart.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
String selectedQty = quantity_txt.getText().toString();
if (session.isLoggedIn()) {
if (!selectedQty.isEmpty() && Integer.parseInt(selectedQty) > Integer.parseInt(qty)) {
AlertDialog.Builder builder = new AlertDialog.Builder(ProductDetailActivity.this);
builder.setMessage("You can not add more than" + " " + qty + " " + "units")
.setCancelable(false)
.setPositiveButton("OK", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
//do things
}
});
AlertDialog alert = builder.create();
alert.show();
} else if (selectedQty.isEmpty() || Integer.parseInt(selectedQty) == 0) {
AlertDialog.Builder builder = new AlertDialog.Builder(ProductDetailActivity.this);
builder.setMessage("Please Add Quantity")
.setCancelable(false)
.setPositiveButton("OK", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
//do things
}
});
AlertDialog alert = builder.create();
alert.show();
} else if (!selectedQty.isEmpty() && Integer.parseInt(selectedQty) != 0 && Integer.parseInt(selectedQty) <= Integer.parseInt(qty)) {
addCart.setVisibility(View.GONE);
hideKeyboard(ProductDetailActivity.this);
fm = getSupportFragmentManager();
fragmentTransaction = fm.beginTransaction();
CartFragment cartFragment = new CartFragment();
fragmentTransaction.replace(R.id.fragmentContainer,cartFragment);
Bundle bundle = new Bundle();
bundle.putString("artCode", artCode);
bundle.putString("image",image_url);
bundle.putString("quantity",selectedQty);
bundle.putString("cost",cost);
bundle.putInt("fragment",6);
cartFragment.setArguments(bundle);
fragmentTransaction.addToBackStack(null);
fragmentTransaction.commitAllowingStateLoss();
}
} else {
AlertDialog.Builder builder = new AlertDialog.Builder(ProductDetailActivity.this);
builder.setMessage("Please Login To Continue")
.setCancelable(false)
.setNegativeButton("NOT NOW", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
}
})
.setPositiveButton("LOGIN", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
Intent intent = new Intent(ProductDetailActivity.this, LoginActivity.class);
intent.putExtra("fragment", 7);
startActivity(intent);
}
});
AlertDialog alert = builder.create();
alert.show();
}
}
});
}
public void myOnResume(){
this.onResume();
addCart.setVisibility(View.VISIBLE);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
// todo: goto back activity from here
finish();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
public void showProgreass() {
progressDialog = new ProgressDialog(ProductDetailActivity.this);
progressDialog.setIndeterminate(true);
progressDialog.setMessage("Please Wait...");
progressDialog.setCanceledOnTouchOutside(false);
progressDialog.setCancelable(false);
progressDialog.show();
}
public void stopProgress() {
if (progressDialog != null && progressDialog.isShowing())
progressDialog.cancel();
}
public void callProductDetail(String productId) {
showProgreass();
String url = String.format(ServerConfigStage.GET_PRODUCT_DETAIL(), productId);
RetrofitTask task = new RetrofitTask<List<ProductDetail>>(ProductDetailActivity.this, CommonUtility.HTTP_REQUEST_TYPE.GET, CommonUtility.CallerFunction.GET_PRODUCT_DETAIL, url, ProductDetailActivity.this);
task.execute();
}
@Override
public void onRetrofitTaskComplete(Response<List<ProductDetail>> response, Context context, CommonUtility.CallerFunction _callerFunction) {
stopProgress();
if (response.isSuccess()) {
if (response.body() != null) {
if (response.body().get(0).getStatus() > 0) {
String json = gson.toJson(response);
System.out.println(json);
artCode = response.body().get(0).getItemcode();
cost = response.body().get(0).getPrice();
String desc = response.body().get(0).getDescription();
image_url = response.body().get(0).getURL();
Double d = response.body().get(0).getStock();
Double aDouble = new Double(d);
int i = aDouble.intValue();
qty = String.valueOf(i);
if (qty.equals("0")) {
stock_status.setText("Not In Stock");
stockAvailibility.setImageResource(R.mipmap.stockunavailable);
quantity_txt.setVisibility(View.GONE);
qtyText.setVisibility(View.GONE);
addCart.setVisibility(View.GONE);
} else {
stockAvailibility.setImageResource(R.mipmap.stock_image);
}
code.setText(artCode);
price.setText("Euro" + "" + cost);
productDescription = (ExpandableTextView) findViewById(R.id.expand_text_view);
productDescription.setText(desc);
name.setText(itemName);
stock.setText("Units :" + " " + qty);
Picasso.with(context).load(image_url).resize(240, 120).into(productImage);
} else {
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setMessage(response.body().get(0).getResponse())
.setCancelable(false)
.setPositiveButton("OK", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
//do things
}
});
AlertDialog alert = builder.create();
alert.show();
//Toast.makeText(context, response.body().get(0).getResponse(), Toast.LENGTH_SHORT).show();
}
}
}
}
@Override
public void onRetrofitTaskFailure(Throwable t) {
stopProgress();
//Toast.makeText(ProductDetailActivity.this,"Fail to load Data",Toast.LENGTH_LONG).show();
finish();
}
public static void hideKeyboard(Context ctx) {
InputMethodManager inputManager = (InputMethodManager) ctx
.getSystemService(Context.INPUT_METHOD_SERVICE);
// check if no view has focus:
View v = ((Activity) ctx).getCurrentFocus();
if (v == null)
return;
inputManager.hideSoftInputFromWindow(v.getWindowToken(), 0);
}
}
堆栈跟踪
Process: com.jbm.jbmcustomer, PID: 9188
java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.res.Resources$Theme android.content.Context.getTheme()' on a null object reference
at android.app.AlertDialog.resolveDialogTheme(AlertDialog.java:222)
at android.app.AlertDialog.<init>(AlertDialog.java:200)
at android.app.AlertDialog.<init>(AlertDialog.java:196)
at android.app.AlertDialog.<init>(AlertDialog.java:141)
at android.app.ProgressDialog.<init>(ProgressDialog.java:77)
at com.jbm.jbmcustomer.fragment.CartFragment.showProgreass(CartFragment.java:179)
at com.jbm.jbmcustomer.fragment.CartFragment.delItemCart(CartFragment.java:172)
at com.jbm.jbmcustomer.adapter.AdapterShowCart.onClick(AdapterShowCart.java:80)
at android.view.View.performClick(View.java:5198)
at android.view.View$PerformClick.run(View.java:21147)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
getActivity 返回 null 的原因是，您使用的是在适配器 class 内初始化的购物车片段实例，该实例未附加到任何 activity。 因此，请将 CartFragment 的实例从 CartFragment 传递到适配器 class 以解决问题。 AdapterShowCart class 中有一个构造函数，其中传递了购物车片段实例，但在片段中的 delItemCart(String email,String itemId) 中调用了它（我不明白为什么要这样做）。
在 AdapterShowCart 第 80 行中，您正在触发一个操作，该操作尝试使用对不再存在的上下文的引用从资源中获取值。
据推测，ProductDetailActivity.this 导致了问题。