NullPointerException로 DatePicker이 손상됨

Question

현재 DatePicker을 내 응용 프로그램에 적용했으며 Button을 클릭하면 충돌이 발생했습니다. 아래는 logcat입니다 :

08-18 00:22:39.564: E/AndroidRuntime(793): FATAL EXCEPTION: main 
08-18 00:22:39.564: E/AndroidRuntime(793): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.stts.sparetimetradingsystem/com.stts.sparetimetradingsystem.employer.EditEventActivity}: java.lang.NullPointerException 
08-18 00:22:39.564: E/AndroidRuntime(793): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663) 
08-18 00:22:39.564: E/AndroidRuntime(793): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679) 
08-18 00:22:39.564: E/AndroidRuntime(793): at android.app.ActivityThread.access$2300(ActivityThread.java:125) 
08-18 00:22:39.564: E/AndroidRuntime(793): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033) 
08-18 00:22:39.564: E/AndroidRuntime(793): at android.os.Handler.dispatchMessage(Handler.java:99) 
08-18 00:22:39.564: E/AndroidRuntime(793): at android.os.Looper.loop(Looper.java:123) 
08-18 00:22:39.564: E/AndroidRuntime(793): at android.app.ActivityThread.main(ActivityThread.java:4627) 
08-18 00:22:39.564: E/AndroidRuntime(793): at java.lang.reflect.Method.invokeNative(Native Method) 
08-18 00:22:39.564: E/AndroidRuntime(793): at java.lang.reflect.Method.invoke(Method.java:521) 
08-18 00:22:39.564: E/AndroidRuntime(793): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868) 
08-18 00:22:39.564: E/AndroidRuntime(793): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626) 
08-18 00:22:39.564: E/AndroidRuntime(793): at dalvik.system.NativeStart.main(Native Method) 
08-18 00:22:39.564: E/AndroidRuntime(793): Caused by: java.lang.NullPointerException 
08-18 00:22:39.564: E/AndroidRuntime(793): at com.stts.sparetimetradingsystem.employer.EditEventActivity.updateDisplayFrom(EditEventActivity.java:532) 
08-18 00:22:39.564: E/AndroidRuntime(793): at com.stts.sparetimetradingsystem.employer.EditEventActivity.onCreate(EditEventActivity.java:236) 
08-18 00:22:39.564: E/AndroidRuntime(793): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047) 
08-18 00:22:39.564: E/AndroidRuntime(793): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627) 
08-18 00:22:39.564: E/AndroidRuntime(793): ... 11 more 

죄송합니다. 여기에 내 코드입니다 : 당신이 코드에서 어디 edit_eventFrom를 초기화하지 않은 것처럼 아래

private int mYear; 
private int mMonth; 
private int mDay; 
static final int DATE_DIALOG_ID = 0; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.edit_event); 

    edit_eventSpinner = (Spinner) findViewById(R.id.edit_spinner); 
    btnSaveEvent = (Button) findViewById(R.id.btnSaveEvent); 
    btnDeleteEvent = (Button) findViewById(R.id.btnDeleteEvent); 
    edit_error = (TextView) findViewById(R.id.edit_error); 

    ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(
      this, R.array.salary_array, 
      android.R.layout.simple_spinner_item); 
    adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item); 

    edit_eventSpinner.setAdapter(adapter); 
    edit_eventSpinner 
      .setOnItemSelectedListener(new OnItemSelectedListener() { 
       public void onItemSelected(AdapterView<?> parent, 
         View view, int position, long id) { 

        if (position == 0) { 
         rate = "/hour"; 
        } else if (position == 1) { 
         rate = "/day"; 
        } else { 
         rate = "/month"; 
        } 
       } 

       public void onNothingSelected(AdapterView<?> parent) { 

       } 
      }); 

    // getting event details from intent 
    Intent i = getIntent(); 

    // getting event id (EID) from intent 
    eid = i.getStringExtra(TAG_EID); 

    // Getting complete event details in background thread 
    new GetEventDetails().execute(); 

    // save button click event 
    btnSaveEvent.setOnClickListener(new View.OnClickListener() { 

     public void onClick(View arg0) { 
      // starting background task to update event 
      String e = edit_eventName.getText().toString(); 
      String c = edit_eventCName.getText().toString(); 
      String s = edit_eventSalary.getText().toString(); 
      String f = edit_eventFrom.getText().toString(); 
      String t = edit_eventTo.getText().toString(); 
      String whf = edit_eventWHFrom.getText().toString(); 
      String wht = edit_eventWHTo.getText().toString(); 
    }); 

    // Delete button click event 
    btnDeleteEvent.setOnClickListener(new View.OnClickListener() { 

     public void onClick(View arg0) { 
      // deleting event in background thread 
      new DeleteEvent().execute(); 
     } 
    }); 

    Button edit_pickDateFrom = (Button) findViewById(R.id.edit_pickDateFrom); 

    edit_pickDateFrom.setOnClickListener(new View.OnClickListener() { 
     public void onClick(View v) { 
      showDialog(DATE_DIALOG_ID); 
     } 
    }); 

    updateDisplayFrom(); 
} 

@Override 
protected Dialog onCreateDialog(int id) { 
    switch (id) { 

    case DATE_DIALOG_ID: 
     return new DatePickerDialog(this, mDateSetListenerFrom, mYear, 
       mMonth, mDay); 
    } 
    return null; 
} 

protected void onPrepareDialog(int id, Dialog dialog) { 
    switch (id) { 

    case DATE_DIALOG_ID: 
     ((DatePickerDialog) dialog).updateDate(mYear, mMonth, mDay); 
     break; 
    } 

} 

// SET THE DATE FORMAT ALREADY USER SELECT FROM THE DATEPICKER 
private void updateDisplayFrom() { 
    edit_eventFrom.setText(new StringBuilder() 
      // Month is 0 based so add 1 
      .append(mDay).append("-").append(mMonth + 1).append("-") 
      .append(mYear).append("")); 
} 

private DatePickerDialog.OnDateSetListener mDateSetListenerFrom = new DatePickerDialog.OnDateSetListener() { 

    public void onDateSet(DatePicker view, int year, int monthOfYear, 
      int dayOfMonth) { 
     mYear = year; 
     mMonth = monthOfYear; 
     mDay = dayOfMonth; 
     updateDisplayFrom(); 
    } 
}; 

내가 edit_eventName를 초기화하더라도 후에 내가 얻을 새로운 오류가 등

08-18 01:09:56.764: E/AndroidRuntime(977): FATAL EXCEPTION: main 
08-18 01:09:56.764: E/AndroidRuntime(977): java.lang.IllegalArgumentException: current should be >= start and <= end 
08-18 01:09:56.764: E/AndroidRuntime(977): at android.widget.NumberPicker.setCurrent(NumberPicker.java:288) 
08-18 01:09:56.764: E/AndroidRuntime(977): at android.widget.DatePicker.updateDaySpinner(DatePicker.java:364) 
08-18 01:09:56.764: E/AndroidRuntime(977): at android.widget.DatePicker.updateSpinners(DatePicker.java:350) 
08-18 01:09:56.764: E/AndroidRuntime(977): at android.widget.DatePicker.init(DatePicker.java:346) 
08-18 01:09:56.764: E/AndroidRuntime(977): at android.app.DatePickerDialog.<init>(DatePickerDialog.java:124) 
08-18 01:09:56.764: E/AndroidRuntime(977): at android.app.DatePickerDialog.<init>(DatePickerDialog.java:83) 
08-18 01:09:56.764: E/AndroidRuntime(977): at com.stts.sparetimetradingsystem.employer.EditEventActivity.onCreateDialog(EditEventActivity.java:527) 
08-18 01:09:56.764: E/AndroidRuntime(977): at android.app.Activity.onCreateDialog(Activity.java:2472) 
08-18 01:09:56.764: E/AndroidRuntime(977): at android.app.Activity.createDialog(Activity.java:881) 
08-18 01:09:56.764: E/AndroidRuntime(977): at android.app.Activity.showDialog(Activity.java:2547) 
08-18 01:09:56.764: E/AndroidRuntime(977): at android.app.Activity.showDialog(Activity.java:2514) 
08-18 01:09:56.764: E/AndroidRuntime(977): at com.stts.sparetimetradingsystem.employer.EditEventActivity$5.onClick(EditEventActivity.java:245) 
08-18 01:09:56.764: E/AndroidRuntime(977): at android.view.View.performClick(View.java:2408) 
08-18 01:09:56.764: E/AndroidRuntime(977): at android.view.View$PerformClick.run(View.java:8816) 
08-18 01:09:56.764: E/AndroidRuntime(977): at android.os.Handler.handleCallback(Handler.java:587) 
08-18 01:09:56.764: E/AndroidRuntime(977): at android.os.Handler.dispatchMessage(Handler.java:92) 
08-18 01:09:56.764: E/AndroidRuntime(977): at android.os.Looper.loop(Looper.java:123) 
08-18 01:09:56.764: E/AndroidRuntime(977): at android.app.ActivityThread.main(ActivityThread.java:4627) 
08-18 01:09:56.764: E/AndroidRuntime(977): at java.lang.reflect.Method.invokeNative(Native Method) 
08-18 01:09:56.764: E/AndroidRuntime(977): at java.lang.reflect.Method.invoke(Method.java:521) 
08-18 01:09:56.764: E/AndroidRuntime(977): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868) 
08-18 01:09:56.764: E/AndroidRuntime(977): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626) 
08-18 01:09:56.764: E/AndroidRuntime(977): at dalvik.system.NativeStart.main(Native Method) 

Answer 1

보인다 당신 게시했습니다.

당신이 그랬던 것처럼 당신은 레이아웃에서 해당 View을 팽창해야합니다 다른 Views :

edit_eventSpinner = (Spinner) findViewById(R.id.edit_spinner); 
btnSaveEvent = (Button) findViewById(R.id.btnSaveEvent); 
btnDeleteEvent = (Button) findViewById(R.id.btnDeleteEvent); 
edit_error = (TextView) findViewById(R.id.edit_error); 

그리고 swayam가 언급 한 바와 같이, 당신은 당신이 사용하고자하는 모든 View이 작업을 수행해야합니다 귀하의 코드입니다. 마찬가지로 swayam

는

---

두 번째 오류를 코드에서

, IllegalArgumentException를 사용하기 전에 모든 다음의 EditText 뷰를 초기화 : 현재는> = 시작 < = 끝 당신은 몇 가지 기본 또는 어떤 가치 당신이 원하는에 mYear, mDay 및 mMonth를 초기화해야

해야합니다.

Reference for this solution.

Answer 2

당신은 당신의 XML을 참조하여 글고 뷰의 초기화가 누락되었습니다.

EditText edit_eventName = (EditText) findViewById(R.id.idOfThisEditTextInYourXML); 
EditText edit_eventFrom = (EditText) findViewById(R.id.idOfThisEditTextInYourXML); 

마찬가지로, 코드에서 사용하기 전에 모든 다음의 EditText 뷰를 초기화 : 또한 초기화 mDay, mMonth and mYear에 대한 누락

  edit_eventCName 
      edit_eventSalary 
      edit_eventFrom 
      edit_eventTo 
      edit_eventWHFrom 
      edit_eventWHTo 

. 몇 가지 값 (정수)을 할당해야합니다.

private int mYear = 2012; // example value 
private int mMonth = 7; // example value 
private int mDay =17; // example value