將微調器項目讀取到另一個微調器

Question

我有一個spinner項目，並且該值已插入到SQLite 。現在，我想將該項目檢索到另一個處於Update.java spinner中。

Information.java

 public void addItemsOnSpinner2() {
        spinner2 = (Spinner) findViewById(R.id.spinner2);
        List<String> list = new ArrayList<String>();
        list.add("Sunny");
        list.add("Cloudy");
        list.add("Rainy");
        list.add("Thunderstorm");
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(Information.this, android.R.layout.simple_spinner_dropdown_item, list);
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        spinner2.setAdapter(adapter);

更新.java

  public void addWeather() {
    weather3 = (Spinner) findViewById(R.id.spinner5);
    List<String> list = new ArrayList<String>();
    list.add("Sunny");
    list.add("Cloudy");
    list.add("Rainy");
    list.add("Thunderstorm");
    ArrayAdapter<String> adapter = new ArrayAdapter<String>(UpdatePage.this, android.R.layout.simple_spinner_dropdown_item, list);
    adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    weather3.setAdapter(adapter);
    String Weather = c.getString(c.getColumnIndexOrThrow(MyDatabaseHelper.Weather));
    weather3.setText(Weather);
}

當然，此方法不起作用，無法解析setText 。 我一直在尋找解決方案很長時間，但似乎找不到太多信息。 任何想法或建議將不勝感激。

已編輯

 public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        dbHelper = new MyDatabaseHelper(this);
        setContentView(R.layout.updatepage);
        final String name = getIntent().getExtras().getString("name1");
        final String date=getIntent().getExtras().getString("date1");
        final String ID = getIntent().getExtras().getString("ID");
        addWeather();
        RetrievePage(name,date,ID);
    }

     public void addWeather() {
            weather3 = (Spinner) findViewById(R.id.spinner5);
            String[] arr = new String[]{"Sunny","Cloudy","Rainy","Thunderstorm"};
            List<String> list = new ArrayList<String>();
            String weather = c.getString(c.getColumnIndexOrThrow(MyDatabaseHelper.Weather));
            list.add(weather);
            for(String s:arr){
                if(!list.contains(s)){
                    list.add(s);
                }
            }
            ArrayAdapter<String> adapter = new ArrayAdapter<String>(UpdatePage.this, android.R.layout.simple_spinner_dropdown_item, list);
            adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
            weather3.setAdapter(adapter);
        }

 public void RetrievePage(String name,String date, String id) {
        final String name2 = name;
        final String date2=date;
        final String id2 = id;
        final EditText name3 = (EditText) findViewById(R.id.editText9);
        final EditText date3 = (EditText) findViewById(R.id.editText12);
        name3.setText(name2);
        date3.setText(date2);

        final EditText subC3 = (EditText) findViewById(R.id.editText17);
        final EditText noP = (EditText) findViewById(R.id.editText18);
        final EditText noH = (EditText) findViewById(R.id.editText19);
        final Spinner poject3 = (Spinner) findViewById(R.id.spinner8);


        database = dbHelper.getWritableDatabase();
        c = database.rawQuery("SELECT i.Weather, i.Status,w.Subcontractors, w.NumberOfPerson, w.NumberOfHours FROM Information i LEFT JOIN WorkForce w ON w.TInfo_id = i._id WHERE i.Name = ? AND i._id= ? ",
                new String[]{String.valueOf(name2),String.valueOf(id2)}, null);
        if (c != null) {
            while (c.moveToNext()) {
                Info I = new Info();
                Details WD = new Details();
                Force WF = new Force();
                String Weather = c.getString(c.getColumnIndexOrThrow(MyDatabaseHelper.Weather));
                String Status = c.getString(c.getColumnIndexOrThrow(MyDatabaseHelper.Status));
                String SubC = c.getString(c.getColumnIndexOrThrow(MyDatabaseHelper.Subcontractors));
                String NoP = c.getString(c.getColumnIndexOrThrow(MyDatabaseHelper.NumberOfPerson));
                String NoH = c.getString(c.getColumnIndexOrThrow(MyDatabaseHelper.NumberOfHours));
                I.setWeather(Weather);
                I.setStatus(Status);
                WF.setSubcontractors(SubC);
                WF.setNoOfPerson(NoP);
                WF.setNoOfHours(NoH);
                subC3.setText(SubC);
                noP.setText(NoP);
                noH.setText(NoH);

            }

        }
        c.close();

錯誤

Caused by: java.lang.NullPointerException: Attempt to invoke interface method 'int android.database.Cursor.getColumnIndexOrThrow(java.lang.String)' on a null object reference

Answer 1

我不確定我是否確切了解您要實現的目標，但是如果要在weather3微調器中顯示在spinner2中選擇的項目，則可以執行以下操作：

    public void addWeather() {
        weather3 = (Spinner) findViewById(R.id.spinner5);
        String[] arr = new String[]{"Sunny","Cloudy","Rainy","Thunderstorm"};
        List<String> list = new ArrayList<String>();
        String weather = c.getString(c.getColumnIndexOrThrow(MyDatabaseHelper.Weather));
        list.add(weather);
        for(String s:arr){
            if(!list.contains(s)){
                list.add(s);
            }
        }
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(UpdatePage.this, android.R.layout.simple_spinner_dropdown_item, list);
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        weather3.setAdapter(adapter);
    }

想法是將要顯示的項目添加為ArrayList的第一項。