當我使用日曆時，如何獲得微調值？

我可以得到年和月，但我不能得到天的價值spinner。

它顯示

java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String java.lang.Object.toString()' on a null object reference

我怎樣才能解決這個問題？

下面是代碼：

private void datePick(){ 
     Calendar calendar = Calendar.getInstance(); 

     for (int i = 0; i < 100; i++) { 
      dataYear.add("" + (calendar.get(Calendar.YEAR) - i)); 
     } 

     adapterSpYear = new ArrayAdapter<String>(getActivity(), R.layout.spinner, dataYear); 
     adapterSpYear.setDropDownViewResource(R.layout.support_simple_spinner_dropdown_item); 
     spYear.setAdapter(adapterSpYear); 
     spYear.setSelection(34);//for 1982 

     for (int i = 1; i <= 12; i++) { 
      dataMonth.add("" + (i < 10 ? "0" + i : i)); 
     } 

     adapterSpMonth = new ArrayAdapter<String>(getActivity(), R.layout.spinner, dataMonth); 
     adapterSpMonth.setDropDownViewResource(R.layout.support_simple_spinner_dropdown_item); 
     spMonth.setAdapter(adapterSpMonth); 


     adapterSpDay = new ArrayAdapter<String>(getActivity(), R.layout.spinner, dataDay); 
     adapterSpDay.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item); 
     spDay.setAdapter(adapterSpDay); 

     spMonth.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() { 
      @Override 
      public void onItemSelected(AdapterView<?> adapterView, View view, int arg2, long arg3) { 
       dataDay.clear(); 
       Calendar calendar1 = Calendar.getInstance(); 
       calendar1.set(Calendar.YEAR, Integer.valueOf(spYear.getSelectedItem().toString())); 
       calendar1.set(Calendar.MONTH, arg2); 
       int dayOfMonth = calendar1.getActualMaximum(Calendar.DAY_OF_MONTH); 
       for (int i = 1; i <= dayOfMonth; i++) { 
        dataDay.add("" + (i < 10 ? "0" + i : i)); 
       } 
       adapterSpDay.notifyDataSetChanged(); 


       String year=spYear.getSelectedItem().toString(); 
       String month=spMonth.getSelectedItem().toString(); 
       String day=spDay.getSelectedItem().toString(); 

       Log.i("test",".>>>>Year>>>>"+year); 
       Log.i("test",".>>>>Month>>>>"+month); 
       Log.i("test",".>>>>Day>>>>"+day); 
      } 

      @Override 
      public void onNothingSelected(AdapterView<?> adapterView) { 

      } 
     }); 
    }

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來源

2016-12-28 徐博俊

我認爲你應該在使用它adapterSpDay.clear（）和adapterSpDay.add或addAll做出改變，而不是清算和添加新的數據你dataDay的array – Beyka

檢查spDay.getSelectedItem（）的值。它是空的，因爲你沒有選擇任何一天，你只選擇年份和月份.. –

如果我設置代碼String day = spDay.getSelectedItem（）。toString（）; 啓動應用程序，它會立即崩潰。我從Sangeet獲得瞭解決方案，感謝您的幫助@SHIVANIGARG和Beyka –

在轉適配器adapterSpDay.notifyDataSetChanged();不會刷新適配器的數據。你必須再次裏面創建適配器以及適配器一天

spMonth.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() { 
      @Override 
      public void onItemSelected(AdapterView<?> adapterView, View view, int arg2, long arg3) 
      { // Here create adapter for day again by passing new data and set that adapter to day spinner. 
       ............ 
         }

來源

2016-12-28 07:23:16

謝謝@Sangeet Suresh，我現在解決了這個問題。問題是日適配器的地方。 –

當我使用日曆時，如何獲得微調值？

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