Question

我已经能够将一个条目保存到共享首选项，并且可以在另一个视图的列表视图中显示，但我想添加多个条目并将它们显示在列表视图中。我以为我有正确的代码，但它没有看到mto已经改变了什么。我的意图是收藏列表，我从一个视图中获取条目数据并在另一个视图中显示它。

SingleView活动：

SharedPreferences.Editor fd;
SharedPreferences FeedPref;

private ArrayList<String> addArray = new ArrayList<>();

    txt = (TextView) findViewById(R.id.name);

    add = (Button) findViewById(R.id.btnAdd);
    FeedPref = PreferenceManager.getDefaultSharedPreferences(getBaseContext());
    fd = FeedPref.edit();


    add.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {

            String message = txt.getText().toString();

            if (addArray.contains(message)) {
                Toast.makeText((getBaseContext()), "Plant Already Added", Toast.LENGTH_LONG).show();
            } else {
                addArray.add(message);

                FeedPref = PreferenceManager.getDefaultSharedPreferences(getBaseContext());
                fd = FeedPref.edit();
                fd.putInt("array_size", addArray.size());

                for (int i = 0; i < addArray.size(); i++) {
                    fd.putString("Status_" + i, addArray.get(i));
                }
                   fd.commit();
                    Toast.makeText((getBaseContext()), "Plant Added", Toast.LENGTH_LONG).show();
                }
            }
        });
    }

mygarden活动：

public class mygardenMain extends Activity {
//String[] presidents;
ListView listView;
//ArrayAdapter<String> adapter;
SharedPreferences FeedPref;
SharedPreferences.Editor fd;
//private ArrayList<String> addArray;
//public static final String PREFS = "examplePrefs";

@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.mygarden_list);
    listView = (ListView) findViewById(R.id.mygardenlist);
    //addArray = new ArrayList<>();

    FeedPref = PreferenceManager.getDefaultSharedPreferences(getBaseContext());

    int size = FeedPref.getInt("array_size", 0);

    for (int i = 0; i < size; i++) {
        String mess = FeedPref.getString("Status_" + i, null);
        String[] values = new String[]{mess};

        ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, values);
        listView.setAdapter(adapter);

    }
}

Answer 1

SingleView活动：

    SharedPreferences.Editor fd;
    SharedPreferences FeedPref;

    private ArrayList<String> addArray = new ArrayList<>();

        txt = (TextView) findViewById(R.id.name);

        add = (Button) findViewById(R.id.btnAdd);
        FeedPref = PreferenceManager.getDefaultSharedPreferences(getBaseContext());
        fd = FeedPref.edit();


        add.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {

                String message = txt.getText().toString();

                if (addArray.contains(message)) {
                    Toast.makeText((getBaseContext()), "Plant Already Added", Toast.LENGTH_LONG).show();
                } else {

                   FeedPref = PreferenceManager.getDefaultSharedPreferences(getBaseContext());
                    fd = FeedPref.edit();

                    Gson gson = new Gson();
                    String jsonText = Prefs.getString("key", "");
                    if(!jsonText.equals(""))
                    {
                        String[] text = gson.fromJson(jsonText, String[].class);  //EDIT: gso to gson
                        if(text.length>0)
                        {
                            //addArray = Arrays.asList(text);
                            //addArray = new ArrayList(addArray);
                            List<String> addArrayNew = Arrays.asList(text);
                            addArray = new ArrayList(addArrayNew);

                        }
                    }
                    addArray.add(message);

                    gson = new Gson();
                    jsonText = gson.toJson(addArray );
                    prefsEditor.putString("key", jsonText);
                    prefsEditor.commit();
                }
            });
        }

mygarden活动：

    public class mygardenMain extends Activity {
    //String[] presidents;
    ListView listView;
    //ArrayAdapter<String> adapter;
    SharedPreferences FeedPref;
    SharedPreferences.Editor fd;
    //private ArrayList<String> addArray;
    //public static final String PREFS = "examplePrefs";
    String jsonText;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.mygarden_list);
        listView = (ListView) findViewById(R.id.mygardenlist);
        //addArray = new ArrayList<>();

        FeedPref = PreferenceManager.getDefaultSharedPreferences(getBaseContext());

        int size = FeedPref.getInt("array_size", 0);

         Gson gson = new Gson();
         jsonText = FeedPref.getString("key", "");
         if(!jsonText.equals(""))
         {
           String[] values= gson.fromJson(jsonText, String[].class);
           ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, values);
           listView.setAdapter(adapter);
        }

    }

Answer 2

设置abc = new HashSet＆lt;＆gt;（）;

abc.add（ “约翰”）;

abc.add（ “测试”）;

abc.add（ “再次”）;

    SharedPreferences sharedPref = this.getPreferences(Context.MODE_PRIVATE);
    SharedPreferences.Editor editor = sharedPref.edit();

    editor.putStringSet("key",abc);

    editor.commit();

如何将字符串集保存到共享首选项

2 个答案: