Question

SecondFragment

我已经创建了一个Tab活动。将一个片段的值发送到另一个片段时，我在ArrayList中得到空值。我在第二个片段中获取值，但无法将其设置为ArrayList。我正在使用__add__在行中显示值。

RecyclerView

FirstFragment

    import android.app.Application;
    import android.content.Context;
    import android.os.Bundle;
    import android.support.v4.app.Fragment;
    import android.support.v7.widget.LinearLayoutManager;
    import android.support.v7.widget.RecyclerView;
    import android.util.Log;
    import android.view.LayoutInflater;
    import android.view.View;
    import android.view.ViewGroup;
    import android.widget.RelativeLayout;
    import android.widget.TextView;
    import android.widget.Toast;

    import java.lang.reflect.Array;
    import java.util.ArrayList;
    import java.util.Arrays;
    import java.util.List;
    import java.util.Random;
    import java.util.jar.Attributes;

    public class Registration_Details extends Fragment {

        RecyclerView recyclerView;
        ArrayList list;
        List<String> list2;
        MyAddapter myAddapter;
        Context context;
        Bundle bundle;
        TextView textView,textView2,textView3;
        String name, contact,email;
        private Random mRandom = new Random();
        private TextView memail,mphone,muser;
        View rootView;

        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);

            ArrayValueAdd();


        }

        private void ArrayValueAdd() {

            Bundle bundle = this.getArguments();

            if (bundle != null) {

                name = bundle.getString("Name");
                contact = bundle.getString("Contact");
                email = bundle.getString("Email");




            }


            list = new ArrayList<String>(3);


            for (int i = 0; i <= 5; i++) {


//Here unable to getting the value
                list.add(name);
                list.add(contact);
                list.add(email);

//Getting the value in Log.e

                Log.e(name, "This is my message");


            }

        }

        @Override
        public void onStart() {
            super.onStart();
            ArrayValueAdd();
        }

            @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                                 Bundle savedInstanceState) {
            rootView = inflater.inflate(R.layout.registration_details, container, false);
            recyclerView = (RecyclerView) rootView.findViewById(R.id.recycler_view);
            recyclerView.setHasFixedSize(true);

            LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this.getActivity());
            linearLayoutManager.setOrientation(LinearLayoutManager.VERTICAL);
            recyclerView.setLayoutManager(linearLayoutManager);






                RelativeLayout relativeLayout = (RelativeLayout) rootView.findViewById(R.id.tv);




            myAddapter = new MyAddapter(getActivity(), list, new OnMyItemClickListner() {
                @Override
                public void onItemClicked(int pos) {


                }
            }, new OndeleteItem() {

                @Override
                public void ondelete(int pos) {



                    Toast.makeText(getActivity(), String.valueOf(name), Toast.LENGTH_LONG).show();

                    myAddapter.notifyDataSetChanged();
                }

        }




            );

             recyclerView.setAdapter(myAddapter);
            return rootView;
        }


    }

更新的SecondFragment

import android.os.Bundle;
import android.service.carrier.CarrierMessagingService;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

public class Registration_Tab  extends Fragment {

    EditText editTextName, editTextContact,editTextEmail;
    View rootView;
    Button submitButton;
    String name,contact,email;
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.registration_tab, container, false);

        editTextName = (EditText)rootView.findViewById(R.id.editTextName);

        editTextContact = (EditText)rootView.findViewById(R.id.editTextContact);

        editTextEmail = (EditText)rootView.findViewById(R.id.editTextEmail);

        submitButton = (Button) rootView.findViewById(R.id.button);




        submitButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                name = editTextName.getText().toString();
                contact = editTextContact.getText().toString();
                email = editTextEmail.getText().toString();

                Bundle bundle=new Bundle();
                bundle.putString("Name",name);
                bundle.putString("Contact",contact);
                bundle.putString("Email",email);






            FragmentTransaction transection=getFragmentManager().beginTransaction();
            Registration_Details registration_details=new Registration_Details();
                registration_details.setArguments(bundle); //data being send to SecondFragment
                transection.replace(R.id.constraintLayout, registration_details);
                transection.commit();

                Toast.makeText(getActivity(),"Goingg  " +name,Toast.LENGTH_LONG).show();


            }
        });






        return rootView;
    }


}

MyAddapter

import android.app.Application;
import android.content.Context;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.RelativeLayout;
import android.widget.TextView;
import android.widget.Toast;

import java.lang.reflect.Array;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Random;
import java.util.jar.Attributes;

public class Registration_Details extends Fragment {

    RecyclerView recyclerView;
    ArrayList list;
    List<String> list2;
    MyAddapter myAddapter;
    Context context;
    Bundle bundle;
    TextView textView,textView2,textView3;
    String name, contact,email;
    private Random mRandom = new Random();
    private TextView memail,mphone,muser;
    View rootView;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);




    }


    @Override
    public void onStart() {
        super.onStart();
    }

        @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        rootView = inflater.inflate(R.layout.registration_details, container, false);
        recyclerView = (RecyclerView) rootView.findViewById(R.id.recycler_view);
        recyclerView.setHasFixedSize(true);

        LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this.getActivity());
        linearLayoutManager.setOrientation(LinearLayoutManager.VERTICAL);
        recyclerView.setLayoutManager(linearLayoutManager);


            Bundle bundle = this.getArguments();

            if (bundle != null) {

                name = bundle.getString("Name");
                contact = bundle.getString("Contact");
                email = bundle.getString("Email");




            }


            list = new ArrayList<String>();
            list.add(name);
            list.add(contact);
            list.add(email);

            Log.e(name, "This is my message");




        myAddapter = new MyAddapter(getActivity(), list, new OnMyItemClickListner() {
            @Override
            public void onItemClicked(int pos) {


            }
        }, new OndeleteItem() {

            @Override
            public void ondelete(int pos) {



                Toast.makeText(getActivity(), String.valueOf(name), Toast.LENGTH_LONG).show();

                myAddapter.notifyDataSetChanged();
            }

    }




        );

         recyclerView.setAdapter(myAddapter);
        return rootView;
    }


}

Answer 1

问题出在您的列表初始化和方法位置上，

执行以下操作：

input_shape

并仅在片段的list = new ArrayList<String>();或ArrayValueAdd中调用onCreateView方法，现在这些方法以onViewCreated的生命周期执行，而不是生命周期的执行。 Activity使得它们永远不会执行，因为Fragment已通过状态。

也不需要循环，您可以这样做：

Activity

no不循环。

片段不能直接将数据传递到另一个片段，因此您需要它从父list = new ArrayList<String>(); list.add(name); list.add(contact); list.add(email);

流出

请查看此答案以获取详细说明：here

将值从一个片段发送到另一个片段时，在Arraylist中获取空值

SecondFragment

FirstFragment

更新的SecondFragment

MyAddapter

1 个答案: