我想实现片段通信。实际上我正在尝试将编辑文本数据从一个片段发送到第二个片段。我已经尝试了一些代码，但我的要求没有得到满足。
My First Fragment就在这里
我以不同的方式尝试过，但我无法解决，所以请指导我。
Verification.java 第一个片段
public class Verification extends Fragment {
EditText card_NO,pin_code;
Button button;
Toolbar toolbar;
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view=inflater.inflate(R.layout.verificaton,null);
card_NO=(EditText)view.findViewById(R.id.cardNo);
pin_code=(EditText)view.findViewById(R.id.pin);
button=(Button)view.findViewById(R.id.varify);
toolbar=(Toolbar)view.findViewById(R.id.toolbar);
toolbar.setTitle("Verification");
listeners();
return view;
}
private void listeners() {
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
acc_logIn();
}
});
}
private void acc_logIn(){
String cardid = card_NO.getText().toString().trim();
String pin = pin_code.getText().toString().trim();
verify(cardid,pin);
//
}
private void verify(final String cardid, final String pin){
class UserVerification extends AsyncTask<String,Void,String> {
ProgressDialog loading;
@Override
protected void onPreExecute() {
super.onPreExecute();
loading = ProgressDialog.show(getActivity(),"Please Wait",null,true,true);
}
@Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
loading.dismiss();
if(s.equalsIgnoreCase("Welcome....")){
Toast.makeText(getActivity(),"Successfully Verified",Toast.LENGTH_LONG).show();
String cardid = card_NO.getText().toString();
FragmentManager manager=getFragmentManager();
FragmentTransaction transaction=manager.beginTransaction();
Bundle bundle=new Bundle();
bundle.putString(Config.KEY_ACCOUNT, cardid);
BankServices bankServices=new BankServices();
bankServices.setArguments(bundle);
transaction.add(R.id.myFrame,bankServices);
transaction.commit();
}else{
Toast.makeText(getActivity(),s,Toast.LENGTH_LONG).show();
}
}
@Override
protected String doInBackground(String... params) {
HashMap<String,String> data = new HashMap<>();
data.put("cardid",params[0]);
data.put("pin",params[1]);
RequestHandler rh=new RequestHandler();
String result=rh.sendPostRequest(Config.URL_VERIFY,data);
return result;
}
}
UserVerification uv = new UserVerification();
uv.execute(cardid,pin);
}
}
BankServices.java 第二个片段
public class BankServices extends Fragment {
private Button balance,transfer,bill;
private TextView textView;
private Toolbar toolbar;
@Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
Bundle bundle = this.getArguments();
if (bundle != null) {
String cardid = bundle.getString(Config.KEY_ACCOUNT);
textView.setText(cardid);
}
}
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View v=inflater.inflate(R.layout.services,null);
balance=(Button)v.findViewById(R.id.bt_balanceInq);
transfer=(Button)v.findViewById(R.id.bt_transfer);
bill=(Button)v.findViewById(R.id.bt_payBill);
toolbar= (Toolbar) v.findViewById(R.id.toolbar);
toolbar.setTitle("Services");
// Bundle bundle = this.getArguments();
// if (bundle != null) {
// String cardid = bundle.getString(Config.KEY_ACCOUNT);
// textView.setText(cardid);
// }
listeners();
return v;
}
private void listeners() {
balance.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
FragmentManager manager=getFragmentManager();
FragmentTransaction transaction = manager.beginTransaction();
CheckBal checkBal=new CheckBal();
// transaction.add(R.id.myFrame,checkBal);
transaction.replace(R.id.myFrame,checkBal);
transaction.addToBackStack(null);
transaction.commitAllowingStateLoss();
// transaction.commit();
}
});
transfer.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
FragmentManager manager=getFragmentManager();
FragmentTransaction transaction = manager.beginTransaction();
Transfer tr=new Transfer();
// transaction.add(R.id.myFrame,tr);
transaction.replace(R.id.myFrame,tr);
transaction.addToBackStack(null);
transaction.commitAllowingStateLoss();
}
});
bill.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
FragmentManager manager=getFragmentManager();
FragmentTransaction transaction = manager.beginTransaction();
PayBill payBill=new PayBill();
// transaction.add(R.id.myFrame,payBill);
transaction.replace(R.id.myFrame,payBill);
transaction.addToBackStack(null);
transaction.commitAllowingStateLoss();
}
});
}
}
I try this now and it gives this error occurred ..
流程：com.example.hp.amibank，PID：3532 java.lang.NullPointerException：尝试在空对象引用上调用虚方法'void android.widget.TextView.setText（java.lang.CharSequence）' 在com.example.hp.amibank.BankServices.onViewCreated（BankServices.java:31） 在android.app.FragmentManagerImpl.moveToState（FragmentManager.java:1010） 在android.app.FragmentManagerImpl.moveToState（FragmentManager.java:1171）
答案 0 :(得分：1)
嗨Abdulmateen关注你的问题https://stackoverflow.com/questions/43920934/error-on-sending-data-from-one-fragment-to-another#43920934。你的问题的解决方案是在OnCreateView中添加textView =（TextView）findViewById（id here），类似于bill =（Button）v.findViewById（R.id.bt_payBill）。您的错误堆栈跟踪清楚地表明您正在尝试在尚未初始化textView的null引用上调用setText，希望它有所帮助。
答案 1 :(得分：0)
尝试
Verification.java 第一个片段
public class Verification extends Fragment {
EditText card_NO,pin_code;
Button button;
Toolbar toolbar;
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view=inflater.inflate(R.layout.verificaton,null);
card_NO=(EditText)view.findViewById(R.id.cardNo);
pin_code=(EditText)view.findViewById(R.id.pin);
button=(Button)view.findViewById(R.id.varify);
toolbar=(Toolbar)view.findViewById(R.id.toolbar);
toolbar.setTitle("Verification");
listeners();
return view;
}
private void listeners() {
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
acc_logIn();
String cardid = card_NO.getText().toString();
PayBill payBill = new PayBill();
Bundle bundle = new Bundle();
bundle.putString(Config.KEY_ACCOUNT, cardid);
payBill.setArguments(bundle);
}
});
}
private void acc_logIn(){
String cardid = card_NO.getText().toString().trim();
String pin = pin_code.getText().toString().trim();
verify(cardid,pin);
//
}
private void verify(final String cardid, final String pin){
class UserVerification extends AsyncTask<String,Void,String> {
ProgressDialog loading;
@Override
protected void onPreExecute() {
super.onPreExecute();
loading = ProgressDialog.show(getActivity(),"Please Wait",null,true,true);
}
@Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
loading.dismiss();
if(s.equalsIgnoreCase("Welcome....")){
Toast.makeText(getActivity(),"Successfully Verified",Toast.LENGTH_LONG).show();
FragmentManager manager=getFragmentManager();
FragmentTransaction transaction=manager.beginTransaction();
BankServices bankServices=new BankServices();
transaction.add(R.id.myFrame,bankServices);
transaction.commit();
Bundle bundle=new Bundle();
bundle.putString(Config.KEY_ACCOUNT, cardid);
PayBill payBill=new PayBill();
payBill.setArguments(bundle);
FragmentManager manager= getActivity().getFragmentManager(); //getSupportFragmentManager
FragmentTransaction transaction=manager.beginTransaction();
Bundle bundle=new Bundle();
bundle.putString(Config.KEY_ACCOUNT, cardid);
PayBill payBill=new PayBill();
payBill.setArguments(bundle);
transaction.add(R.id.yourFragmeID,payBill);
transaction.commit();
// Intent intent = new Intent(getActivity(),PayBill.class);
// intent.putExtra(Config.KEY_ACCOUNT,cardid);
// startActivity(intent);
}else{
Toast.makeText(getActivity(),s,Toast.LENGTH_LONG).show();
}
}
@Override
protected String doInBackground(String... params) {
HashMap<String,String> data = new HashMap<>();
data.put("cardid",params[0]);
data.put("pin",params[1]);
RequestHandler rh=new RequestHandler();
String result=rh.sendPostRequest(Config.URL_VERIFY,data);
return result;
}
}
UserVerification uv = new UserVerification();
uv.execute(cardid,pin);
}
}
PayBill.java 已更新
public class PayBill extends Fragment {
private EditText ref;
private EditText bill;
private TextView textView;
private Button fetch,bt_pay;
private ProgressDialog loading;
Toolbar toolbar;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View v=inflater.inflate(R.layout.paybill,null);
ref=(EditText)v.findViewById(R.id.refId);
textView=(TextView)v.findViewById(R.id.tv_c);
bill=(EditText) v.findViewById(R.id.tv_Bill);
fetch=(Button)v.findViewById(R.id.bt_fetch);
bt_pay=(Button)v.findViewById(R.id.bt_payBill);
fetch.setOnClickListener(
new View.OnClickListener() {
@Override
public void onClick(View v) {
getBill();
}
});
bt_pay.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
paybill();
}
});
toolbar=(Toolbar)v.findViewById(R.id.toolbar);
toolbar.setTitle("Pay Bill");
Bundle bundle = this.getArguments();
if (bundle != null) {
String cardid = bundle.getString(Config.KEY_ACCOUNT);
textView.setText(cardid);
}
return v;
}
private void getBill(){
final String rid = ref.getText().toString().trim();
if (rid.equals("")) {
Toast.makeText(getActivity(), "Please enter an id", Toast.LENGTH_LONG).show();
return;
}
loading = ProgressDialog.show(getActivity(),"Please wait ......","fetching....",false,false);
String url = Config.URL_Get_BILL+ref.getText().toString().trim();
StringRequest stringRequest = new StringRequest(url, new Response.Listener<String>() {
@Override
public void onResponse(String response) {
loading.dismiss();
showJSON(response);
}
},
new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
Toast.makeText(getActivity(),error.getMessage().toString(),Toast.LENGTH_LONG).show();
}
});
RequestQueue requestQueue = Volley.newRequestQueue(getActivity());
requestQueue.add(stringRequest);
}
private void showJSON(String response){
String sbill="";
try {
JSONObject jsonObject = new JSONObject(response);
JSONArray result = jsonObject.getJSONArray(Config.TAG_JSON_ARRAY);
JSONObject collegeData = result.getJSONObject(0);
sbill = collegeData.getString(Config.TAG_SHOW_BILL);
} catch (JSONException e) {
e.printStackTrace();
}
bill.setText(sbill);
}
private void paybill() {
final String rid = ref.getText().toString().trim();
final String paydue = bill.getText().toString().trim();
final String cardid=textView.getText().toString().trim();
loading = ProgressDialog.show(getActivity(), "Please wait ......", "Working....", false, false);
StringRequest stringRequest = new StringRequest(Request.Method.POST, Config.URL_PAY_BILL,
new Response.Listener<String>() {
@Override
public void onResponse(String response) {
loading.dismiss();
Toast.makeText(getActivity(), response, Toast.LENGTH_LONG).show();
}
},
new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
loading.dismiss();
Toast.makeText(getActivity(), error.toString(), Toast.LENGTH_LONG).show();
Toast.makeText(getActivity(), error.toString(), Toast.LENGTH_LONG).show();
Toast.makeText(getActivity(), error.toString(), Toast.LENGTH_LONG).show();
}
}) {
@Override
protected Map<String, String> getParams() {
Map<String, String> params = new HashMap<String, String>();
params.put(Config.KEY_ACCOUNT, cardid);
params.put(Config.KEY_BILL_ID,rid);
params.put(Config.KEY_BILL_DUE, paydue);
return params;
}
};
RequestQueue requestQueue = Volley.newRequestQueue(getActivity());
requestQueue.add(stringRequest);
}
}
答案 2 :(得分：0)
问题出现在第一个片段中，您的起始BankService片段只是创建了PayBill的对象，
代码已更新
private void verify(final String cardid, final String pin){
class UserVerification extends AsyncTask<String,Void,String> {
ProgressDialog loading;
@Override
protected void onPreExecute() {
super.onPreExecute();
loading = ProgressDialog.show(getActivity(),"Please Wait",null,true,true);
}
@Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
loading.dismiss();
if(s.equalsIgnoreCase("Welcome....")){
Toast.makeText(getActivity(),"Successfully Verified",Toast.LENGTH_LONG).show();
FragmentManager manager=getFragmentManager();
FragmentTransaction transaction=manager.beginTransaction();
Bundle bundle=new Bundle();
bundle.putString(Config.KEY_ACCOUNT, cardid);
PayBill payBill=new PayBill();
payBill.setArguments(bundle);
transaction.add(R.id.myFrame,payBill);
transaction.commit();
}else{
Toast.makeText(getActivity(),s,Toast.LENGTH_LONG).show();
}
}
@Override
protected String doInBackground(String... params) {
HashMap<String,String> data = new HashMap<>();
data.put("cardid",params[0]);
data.put("pin",params[1]);
RequestHandler rh=new RequestHandler();
String result=rh.sendPostRequest(Config.URL_VERIFY,data);
return result;
}
}
UserVerification uv = new UserVerification();
uv.execute(cardid,pin);
}
答案 3 :(得分：0)
我希望这会对你有所帮助
在Post方法中更改片段1
Fragment PayBill = new PayBill();
Bundle bundle = new Bundle();
bundle.putString(Config.KEY_ACCOUNT, cardid);
PayBill.setArguments(bundle);
FragmentManager fragmentManager = getActivity().getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.add(R.id.myFrame, PayBill);
fragmentTransaction.commit();
// -----------片段2 ---------------
public class PayBill extends Fragment {
private EditText ref;
private EditText bill;
private TextView textView;
String cardid;
private Button fetch,bt_pay;
private ProgressDialog loading;
Toolbar toolbar;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Bundle bundle = this.getArguments();
if (bundle != null) {
cardid = getArguments().getString(Config.KEY_ACCOUNT);
}
}
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View v=inflater.inflate(R.layout.paybill,null);
ref=(EditText)v.findViewById(R.id.refId);
textView=(TextView)v.findViewById(R.id.tv_c);
bill=(EditText) v.findViewById(R.id.tv_Bill);
fetch=(Button)v.findViewById(R.id.bt_fetch);
bt_pay=(Button)v.findViewById(R.id.bt_payBill);
textView.setText(cardid);
fetch.setOnClickListener(
new View.OnClickListener() {
@Override
public void onClick(View v) {
getBill();
}
});
bt_pay.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
paybill();
}
});
toolbar=(Toolbar)v.findViewById(R.id.toolbar);
toolbar.setTitle(“Pay Bill”);
return v;
}
private void getBill(){
final String rid = ref.getText().toString().trim();
if (rid.equals(“”)) {
Toast.makeText(getActivity(), “Please enter an id”, Toast.LENGTH_LONG).show();
return;
}
loading = ProgressDialog.show(getActivity(),“Please wait ......“,”fetching....“,false,false);
String url = Config.URL_Get_BILL+ref.getText().toString().trim();
StringRequest stringRequest = new StringRequest(url, new Response.Listener<String>() {
@Override
public void onResponse(String response) {
loading.dismiss();
showJSON(response);
}
},
new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
Toast.makeText(getActivity(),error.getMessage().toString(),Toast.LENGTH_LONG).show();
}
});
RequestQueue requestQueue = Volley.newRequestQueue(getActivity());
requestQueue.add(stringRequest);
}
private void showJSON(String response){
String sbill=“”;
try {
JSONObject jsonObject = new JSONObject(response);
JSONArray result = jsonObject.getJSONArray(Config.TAG_JSON_ARRAY);
JSONObject collegeData = result.getJSONObject(0);
sbill = collegeData.getString(Config.TAG_SHOW_BILL);
} catch (JSONException e) {
e.printStackTrace();
}
bill.setText(sbill);
}
private void paybill() {
final String rid = ref.getText().toString().trim();
final String paydue = bill.getText().toString().trim();
final String cardid=textView.getText().toString().trim();
loading = ProgressDialog.show(getActivity(), “Please wait ......“, “Working....“, false, false);
StringRequest stringRequest = new StringRequest(Request.Method.POST, Config.URL_PAY_BILL,
new Response.Listener<String>() {
@Override
public void onResponse(String response) {
loading.dismiss();
Toast.makeText(getActivity(), response, Toast.LENGTH_LONG).show();
}
},
new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
loading.dismiss();
Toast.makeText(getActivity(), error.toString(), Toast.LENGTH_LONG).show();
Toast.makeText(getActivity(), error.toString(), Toast.LENGTH_LONG).show();
Toast.makeText(getActivity(), error.toString(), Toast.LENGTH_LONG).show();
}
}) {
@Override
protected Map<String, String> getParams() {
Map<String, String> params = new HashMap<String, String>();
params.put(Config.KEY_ACCOUNT, cardid);
params.put(Config.KEY_BILL_ID,rid);
params.put(Config.KEY_BILL_DUE, paydue);
return params;
}
};
RequestQueue requestQueue = Volley.newRequestQueue(getActivity());
requestQueue.add(stringRequest);
}
}