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Android / MySQL：Spinner不填充MySQL中的數據

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ibeautiful 2022-08-05 15:36:25

我的代碼有問題。我已經創建了一個從MySQL數據庫填充的微調器。PHP代碼似乎根本沒有問題，因為我運行鏈接“localhost/latihan1/menu/php”，json字符串將顯示。json 顯示如下：{“result”：[{“username”：“haha”，“name”：“Bus Bisnis”，“course”：“math”，“session”：“20119”}，{“username”：“hihi”，“name”：“Bus Ace”，“course”：“fizik”，“session”：“12817”}，{“username”：“m_ridwan”，“name”：“Ridwan”，“course”：“Komputer”，“session”：“1920”}，{“username”：“m_iqbal”，“name”：“Iqbal”，“course”：“Sains”，“session”：“2021”}]}但是當我打開應用程序時，微調器不會顯示數據。我不知道為什么。以下是我的代碼爪哇島公共類 MainActivity 擴展 AppCompatActivity 實現 Spinner.OnItemSelectedListener{ private Spinner spinner; private ArrayList<String> students; //JSON Array private JSONArray result; private TextView textViewName; private TextView textViewCourse; private TextView textViewSession; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); //Initializing the ArrayList students = new ArrayList<String>(); spinner = findViewById(R.id.spinner); spinner.setOnItemSelectedListener(this); textViewName = findViewById(R.id.textViewName); textViewCourse = findViewById(R.id.textViewCourse); textViewSession = findViewById(R.id.textViewSession); getData(); } private void getData(){ StringRequest stringRequest = new StringRequest(Config.DATA_URL, new Response.Listener<String>() { @Override public void onResponse(String response) { JSONObject j = null; try { j = new JSONObject(response); result = j.getJSONArray(Config.JSON_ARRAY); getStudents(result); } catch (JSONException e) { e.printStackTrace(); } }

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慕姐8265434

TA貢獻1813條經驗獲得超2個贊

我在我的安卓工作室里執行了你的代碼。我看起來您的網絡調用無法獲取數據（結果保持為空）。檢查我的代碼以供參考。我用靜態數據替換了您的網絡呼叫。

package com.attiq.testapp;

import android.os.Bundle;

import android.view.View;

import android.widget.AdapterView;

import android.widget.ArrayAdapter;

import android.widget.Spinner;

import android.widget.TextView;

import androidx.appcompat.app.AppCompatActivity;

import com.google.gson.Gson;

import com.google.gson.JsonArray;

import com.google.gson.JsonObject;

import org.json.JSONArray;

import org.json.JSONException;

import org.json.JSONObject;

import java.util.ArrayList;

public class Main5Activity extends AppCompatActivity implements Spinner.OnItemSelectedListener {

private Spinner spinner;

private ArrayList<String> students;

//JSON Array

private JSONArray result;

private TextView textViewName;

private TextView textViewCourse;

private TextView textViewSession;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main5);

//Initializing the ArrayList

students = new ArrayList<String>();

spinner = findViewById(R.id.spinner);

spinner.setOnItemSelectedListener(this);

textViewName = findViewById(R.id.textViewName);

textViewCourse = findViewById(R.id.textViewCourse);

textViewSession = findViewById(R.id.textViewSession);

getData();

}

private void getData(){

String json= "{\"result\":[{\"username\":\"haha\",\"name\":\"Bus Bisnis\",\"course\":\"math\",\"session\":\"20119\"},{\"username\":\"hihi\",\"name\":\"Bus Ace\",\"course\":\"fizik\",\"session\":\"12817\"},{\"username\":\"m_ridwan\",\"name\":\"Ridwan\",\"course\":\"Komputer\",\"session\":\"1920\"},{\"username\":\"m_iqbal\",\"name\":\"Iqbal\",\"course\":\"Sains\",\"session\":\"2021\"}]}";

try {

JSONObject jsonObject = new JSONObject(json);

result= jsonObject.getJSONArray("result");

getStudents(result);

} catch (Exception e){

e.printStackTrace();

}

private void getStudents(JSONArray j) {

for (int i = 0; i < j.length(); i++) {

try {

JSONObject json = j.getJSONObject(i);

students.add(json.getString(Config.TAG_USERNAME));

} catch (JSONException e) {

e.printStackTrace();

}

spinner.setAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_spinner_dropdown_item, students));

}

private String getName(int position) {

String name = "";

try {

JSONObject json = result.getJSONObject(position);

name = json.getString(Config.TAG_NAME);

} catch (JSONException e) {

e.printStackTrace();

}

return name;

}

private String getCourse(int position) {

String course = "";

try {

JSONObject json = result.getJSONObject(position);

course = json.getString(Config.TAG_COURSE);

} catch (JSONException e) {

e.printStackTrace();

}

return course;

}

private String getSession(int position) {

String session = "";

try {

JSONObject json = result.getJSONObject(position);

session = json.getString(Config.TAG_SESSION);

} catch (JSONException e) {

e.printStackTrace();

}

return session;

}

@Override

public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {

//Setting the values to textviews for a selected item

textViewName.setText(getName(position));

textViewCourse.setText(getCourse(position));

textViewSession.setText(getSession(position));

}

@Override

public void onNothingSelected(AdapterView<?> parent) {

textViewName.setText("");

textViewCourse.setText("");

textViewSession.setText("");

}

反對回復 2022-08-05

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Android / MySQL：Spinner不填充MySQL中的數據

Android / MySQL：Spinner不填充MySQL中的數據

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