android - Android学习应用程序存储数据的方法有哪些

Question

我将编写一个允许学习语言编程的 Android 应用程序。一个例子，它是 PHP:我的应用程序将具有两个功能:

• 功能 A:学习理论，就像这样:http://www.tutorialspoint.com/php/
• 功能 B:面试问题，例如:http://www.tutorialspoint.com/php/php_interview_questions.htm

使用函数 A，我为每篇文章创建 html 页面，将 html 页面存储在项目中，然后通过 webview 显示它，就像这样:

webView.loadUrl("file:///android_asset/" + value);

注意:值是存储在 Assets 文件夹中的 html 文件。

有了功能B，就有那么多的问答。创建 html 文件太长了。我考虑过 XML 或 JSON 格式。这样做合适吗？您还有其他更好的解决方案吗？

p/s:抱歉关于标签，我不能用我的声誉做完整的标签。

Answer 1

基于:
Home » Android JSON Parsing – Retrieve From MySQL DatabaseAndroid JSON Parsing
从 2015 年 4 月 20 日起，作者:Belal Khan

您可以将数据存储在 MySQL 数据库中，并使用 PHP JSON 加载它。
例如对JSON进行编码的PHP文件为:

<?php
define('HOST','localhost');
define('USER','user');
define('PASS','pass');
define('DB','dbname');
$con = mysqli_connect(HOST,USER,PASS,DB);
$sql = "select * from questions";
$res = mysqli_query($con,$sql);
$result = array(); 
while($row = mysqli_fetch_array($res)){
    array_push($result,
        array('id'=>$row[0],
              'question'=>$row[1],
              'answer'=>$row[2]
    ));
}
echo json_encode(array("result"=>$result));
mysqli_close($con);
?>

Java代码是:

public class MainActivity extends ActionBarActivity {

String myJSON;

private static final String TAG_RESULTS="result";
private static final String TAG_ID = "id";
private static final String TAG_QUESTION = "question";
private static final String TAG_ANSWER ="answer";

JSONArray peoples = null;

ArrayList<HashMap<String, String>> QuestionList;

ListView list;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    list = (ListView) findViewById(R.id.listView);
    QuestionList = new ArrayList<HashMap<String,String>>();
    getData();
}


protected void showList(){
    try {
        JSONObject jsonObj = new JSONObject(myJSON);
        results = jsonObj.getJSONArray(TAG_RESULTS);

        for(int i=0;i<results.length();i++){
            JSONObject c = peoples.getJSONObject(i);
            String id = c.getString(TAG_ID);
            String question = c.getString(TAG_QUESTION);
            String answer = c.getString(TAG_ANSWER);

            HashMap<String,String> questions = new HashMap<String,String>();

            questions.put(TAG_ID,id);
            questions.put(TAG_QUESTION,question);
            questions.put(TAG_ANSWER,answer);

            QuestionList.add(questions);
        }

        ListAdapter adapter = new SimpleAdapter(
                MainActivity.this, personList, R.layout.list_item,
                new String[]{TAG_ID,TAG_QUESTION,TAG_ANSWER},
                new int[]{R.id.id, R.id.question, R.id.answer}
        );

        list.setAdapter(adapter);

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

}

public void getData(){
    class GetDataJSON extends AsyncTask<String, Void, String>{

        @Override
        protected String doInBackground(String... params) {
            DefaultHttpClient httpclient = new DefaultHttpClient(new BasicHttpParams());
            HttpPost httppost = new HttpPost("http://10.0.2.2/get-data.php");

            // Depends on your web service
            httppost.setHeader("Content-type", "application/json");

            InputStream inputStream = null;
            String result = null;
            try {
                HttpResponse response = httpclient.execute(httppost);
                HttpEntity entity = response.getEntity();

                inputStream = entity.getContent();
                // json is UTF-8 by default
                BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream, "UTF-8"), 8);
                StringBuilder sb = new StringBuilder();

                String line = null;
                while ((line = reader.readLine()) != null)
                {
                    sb.append(line + "\n");
                }
                result = sb.toString();
            } catch (Exception e) {
                // Oops
            }
            finally {
                try{if(inputStream != null)inputStream.close();}catch(Exception squish){}
            }
            return result;
        }

        @Override
        protected void onPostExecute(String result){
            myJSON=result;
            showList();
        }
    }
    GetDataJSON g = new GetDataJSON();
    g.execute();
}

你必须在你的布局中添加一个 ListView 并且不要忘记在 list 中添加互联网权限。