java - 无法在 Fragment Activity 上删除和创建数据

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我正在尝试从 API 网页删除并创建数据字符串，但无法获取错误代码我从 native php 创建 API 网站。但我在 postman 工作插入和删除数据上创建数据

代码删除数据

package com.dev.kedaiit.sibooks.ui.kategori;

import android.app.ProgressDialog;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import androidx.appcompat.app.AppCompatActivity;

import com.android.volley.AuthFailureError;
import com.android.volley.Request;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.StringRequest;
import com.dev.kedaiit.sibooks.MainActivity;
import com.dev.kedaiit.sibooks.R;
import com.dev.kedaiit.sibooks.util.AppController;
import com.dev.kedaiit.sibooks.util.ServerAPI;

import org.json.JSONException;
import org.json.JSONObject;

import java.util.HashMap;
import java.util.Map;

public class DeleteKategori extends AppCompatActivity {
    EditText deleteID ;
    Button btnDelete;
    ProgressDialog pd;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_delete_kategori);

        deleteID = (EditText) findViewById(R.id.id_kategori);
        btnDelete = (Button) findViewById(R.id.btn_delete);
        pd = new ProgressDialog(DeleteKategori.this);

        btnDelete.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                deleteData();
            }
        });
    }

    private void deleteData()
    {
        pd.setMessage("Delete Data ...");
        pd.setCancelable(true);
        pd.show();

        StringRequest delReq = new StringRequest(Request.Method.POST, ServerAPI.URL_DELETE_KATEGORI, new Response.Listener<String>() {
                    @Override
                    public void onResponse(String response) {
                        pd.cancel();
                        Log.d("volley","response : " + response.toString());
                        try {
                            JSONObject res = new JSONObject(response);
                            Toast.makeText(DeleteKategori.this,"Successs" +res.getString("message"), Toast.LENGTH_SHORT).show();

                        } catch (JSONException e) {
                            e.printStackTrace();
                        }


                        startActivity(new Intent(DeleteKategori.this, KategoriFragment.class));
                    }
                },
                new Response.ErrorListener() {
                    @Override
                    public void onErrorResponse(VolleyError error) {
                        pd.cancel();
                        Log.d("volley", "error : " + error.getMessage());
                        Toast.makeText(DeleteKategori.this, "ERROR DELETE DATA", Toast.LENGTH_SHORT).show();
                    }
                }){
            @Override
            protected Map<String, String> getParams() throws AuthFailureError {
                Map<String, String> map = new HashMap<>();
                map.put("id_kategori",deleteID.getText().toString());
                return map;
            }
        };

        AppController.getInstance().addToRequestQueue(delReq);
    }
}

代码插入数据

package com.dev.kedaiit.sibooks.ui.kategori;

import android.app.ProgressDialog;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import androidx.appcompat.app.AppCompatActivity;

import com.android.volley.AuthFailureError;
import com.android.volley.Request;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.StringRequest;
import com.dev.kedaiit.sibooks.R;
import com.dev.kedaiit.sibooks.util.AppController;
import com.dev.kedaiit.sibooks.util.ServerAPI;

import org.json.JSONException;
import org.json.JSONObject;

import java.util.HashMap;
import java.util.Map;

public class InsertKategori extends AppCompatActivity {
    EditText id_kategori, kategori;
    Button btnBatal, btnSimpan;
    ProgressDialog pd;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_insert_kategori);

        /*get data from intent*/
        Intent data = getIntent();
        final int update = data.getIntExtra("update",0);
        String intent_idkategori = data.getStringExtra("id_kategori");
        String intent_kategori = data.getStringExtra("kategori");
        /*end get data from intent*/

//        id_kategori = (EditText) findViewById(R.id.idkategori);
        kategori = (EditText) findViewById(R.id.edt_kategori);
        btnBatal = (Button) findViewById(R.id.btn_cancel);
        btnSimpan = (Button) findViewById(R.id.btn_simpan);
        pd = new ProgressDialog(InsertKategori.this);

        /*kondisi update / insert*/
        if(update == 1)
        {
            btnSimpan.setText("Update Data");
            id_kategori.setText(intent_idkategori);
            id_kategori.setVisibility(View.VISIBLE);
            kategori.setText(intent_kategori);

        }


        btnSimpan.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                if(update == 1)
                {
                    Update_data();
                }else {
                    simpanData();
                }
            }
        });

        btnBatal.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent main = new Intent(InsertKategori.this,KategoriFragment.class);
                startActivity(main);
            }
        });
    }

    private void Update_data()
    {
        pd.setMessage("Update Data");
        pd.setCancelable(true);
        pd.show();

        StringRequest updateReq = new StringRequest(Request.Method.POST, ServerAPI.URL_UPDATE_KATEGORI,
                new Response.Listener<String>() {
                    @Override
                    public void onResponse(String response) {
                        pd.cancel();
                        try {
                            JSONObject res = new JSONObject(response);
                            Toast.makeText(InsertKategori.this, ""+   res.getString("message") , Toast.LENGTH_SHORT).show();
                        } catch (JSONException e) {
                            e.printStackTrace();
                        }

                        startActivity( new Intent(InsertKategori.this,KategoriFragment.class));
                    }
                },
                new Response.ErrorListener() {
                    @Override
                    public void onErrorResponse(VolleyError error) {
                        pd.cancel();
                        Toast.makeText(InsertKategori.this, "Gagal Insert Data", Toast.LENGTH_SHORT).show();
                    }
                }){
            @Override
            protected Map<String, String> getParams() throws AuthFailureError {
                Map<String,String> map = new HashMap<>();
                map.put("id_kategori",id_kategori.getText().toString());
                map.put("kategori",kategori.getText().toString());

                return map;
            }
        };

        AppController.getInstance().addToRequestQueue(updateReq);
    }



    private void simpanData()
    {

        pd.setMessage("Menyimpan Data");
        pd.setCancelable(true);
        pd.show();

        StringRequest sendData = new StringRequest(Request.Method.POST, ServerAPI.URL_INSERT_KATEGORI,
                new Response.Listener<String>() {
                    @Override
                    public void onResponse(String response) {
                        pd.cancel();
                        try {
                            JSONObject res = new JSONObject(response);
                            Toast.makeText(InsertKategori.this, ""+   res.getString("message") , Toast.LENGTH_SHORT).show();
                        } catch (JSONException e) {
                            e.printStackTrace();
                        }

                        startActivity( new Intent(InsertKategori.this,KategoriFragment.class));
                    }
                },
                new Response.ErrorListener() {
                    @Override
                    public void onErrorResponse(VolleyError error) {
                        pd.cancel();
                        Toast.makeText(InsertKategori.this, "Gagal Insert Data", Toast.LENGTH_SHORT).show();
                    }
                }){
            @Override
            protected Map<String, String> getParams() throws AuthFailureError {
                Map<String,String> map = new HashMap<>();
                map.put("id_kategori",id_kategori.getText().toString());
                map.put("kategori",kategori.getText().toString());
                return map;
            }
        };

        AppController.getInstance().addToRequestQueue(sendData);
    }

}

fragment 类别

package com.dev.kedaiit.sibooks.ui.kategori;

import android.app.ProgressDialog;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import androidx.fragment.app.Fragment;
import androidx.recyclerview.widget.DividerItemDecoration;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;

import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.JsonObjectRequest;
import com.android.volley.toolbox.Volley;
import com.dev.kedaiit.sibooks.R;
import com.dev.kedaiit.sibooks.adapter.AdapterDataKategori;
import com.dev.kedaiit.sibooks.model.DataKategori;
import com.dev.kedaiit.sibooks.util.ServerAPI;
import com.google.android.material.floatingactionbutton.FloatingActionButton;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.util.ArrayList;
import java.util.List;

public class KategoriFragment extends Fragment {
    private RecyclerView recyclerView;
    private FloatingActionButton floatingActionButton;
    private LinearLayoutManager linearLayoutManager;
    private DividerItemDecoration dividerItemDecoration;
    private List<DataKategori> list;
    private RecyclerView.Adapter adapter;


    public KategoriFragment() {
        // Required empty public constructor
    }

    @Override
    public View onCreateView(final LayoutInflater inflater, final ViewGroup container, Bundle savedInstanceState) {

        final View view = inflater.inflate(R.layout.fragment_kategori, container, false);

        recyclerView = view.findViewById(R.id.recyclerViewKategori);

        list = new ArrayList<DataKategori>();
        adapter = new AdapterDataKategori(getContext(), list);

        linearLayoutManager = new LinearLayoutManager(getContext());
        linearLayoutManager.setOrientation(LinearLayoutManager.VERTICAL);
        dividerItemDecoration = new DividerItemDecoration(recyclerView.getContext(), linearLayoutManager.getOrientation());

        recyclerView.setHasFixedSize(true);
        recyclerView.setLayoutManager(linearLayoutManager);
        recyclerView.addItemDecoration(dividerItemDecoration);
        recyclerView.setAdapter(adapter);


        FloatingActionButton fab = (FloatingActionButton) view.findViewById(R.id.fab);
        FloatingActionButton delKtg = (FloatingActionButton) view.findViewById(R.id.delKtg);

        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent intent = new Intent(view.getContext(), InsertKategori.class);
                startActivity(intent);
            }
        });

        delKtg.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent intent = new Intent(view.getContext(),DeleteKategori.class);
                startActivity(intent);
            }
        });

        getData();

        return view;
    }

    private void getData() {
        final ProgressDialog progressDialog = new ProgressDialog(getContext());
        progressDialog.setMessage("Loading...");
        progressDialog.show();

        JsonObjectRequest my_request = new JsonObjectRequest(Request.Method.GET, ServerAPI.URL_DATA_KATEGORI, null, new Response.Listener<JSONObject>() {
            @Override
            public void onResponse(JSONObject response) {
                try{
                    JSONArray jsonArray = response.getJSONArray("data");
                    for (int i = 0; i < jsonArray.length(); i++) {

                        JSONObject Jobj = jsonArray.getJSONObject(i);

                        DataKategori obj = new DataKategori();
                        obj.setId_kategori(Jobj.getString("id_kategori"));
                        obj.setKategori(Jobj.getString("kategori"));

                        list.add(obj);

                    }
                } catch (JSONException e) {
                    e.printStackTrace();
                    progressDialog.dismiss();
                }
                adapter.notifyDataSetChanged();
                progressDialog.dismiss();
            }
        }, new Response.ErrorListener() {

            @Override
            public void onErrorResponse(VolleyError error) {
                Log.e("Volley", "Error: " + error.getMessage());
                progressDialog.dismiss();
            }
        });

        RequestQueue requestQueue = Volley.newRequestQueue(getContext());
        requestQueue.add(my_request);
    }
}

https://github.com/bellabeen/sibooks-client这个项目我在 logcat 中得到这个，当我没有收到错误代码时

Answer 1

你的代码几乎没问题。你只是错过了一件事。您没有初始化 VolleyRequest。在 simponData 和 UpdateData 方法内部将此行写入底部。

RequestQueue requestQueue = Volley.newRequestQueue(getContext());
requestQueue.add(my_request);

而不是AppController.getInstance().addToRequestQueue(updateReq)。另一件事是，您从收到响应时开始调用 fragment 。成功收到结果后，您应该调用 onbackPress() 。

 new Response.Listener<String>() {
                @Override
                public void onResponse(String response) {
                    pd.cancel();
                    try {
                        JSONObject res = new JSONObject(response);
                        Toast.makeText(InsertKategori.this, ""+   res.getString("message") , Toast.LENGTH_SHORT).show();
                    } catch (JSONException e) {
                        e.printStackTrace();
                    }
                    onBackPressed();
                }
            },

它将恢复之前的 fragment 。为了在收到成功响应时更新 KategoriFragment View ，您可以在 onResume() 方法中调用 getData() 方法，而不是 <强>oncreate()。每当 fragment 对使用可见时，它将调用此方法