从非静态Java获取数据到静态

Question

public class RetrieveActivity extends Activity {
    static String dateData;
    static int choice ;



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

    public void showDatePickerDialogFrom(View v) 
    {   
        choice=1;
        DialogFragment newFragment = new DatePickerFragment();
        newFragment.show(getFragmentManager(), "datePicker");
    }


    public void showDatePickerDialogTo(View v) 
        {   
        choice=2;
        String dateSelected;
        DialogFragment newFragment = new DatePickerFragment();
        newFragment.show(getFragmentManager(), "datePicker");
        }



    public static void populateSetDate(int year,int month,int day)
    {
        dateData = ""+day+"/"+month+"/"+year;
        if(choice==1)
        {
        EditText dateFrom=(EditText)findViewById(R.id.dateTo); <------ error over here on the static to non static stuff.
        dateFrom.setText(dateData);
        }
        else
        {
        EditText dateTo=(EditText)findViewById(R.id.dateFrom1);<--- here also the same.
        dateTo.setText(dateData);
        }
    }

    public static class DatePickerFragment extends DialogFragment
    implements DatePickerDialog.OnDateSetListener 
    {


        @Override
        public Dialog onCreateDialog(Bundle savedInstanceState) 
        {
            // Use the current date as the default date in the picker
            final Calendar c = Calendar.getInstance();
            int year = c.get(Calendar.YEAR);
            int month = c.get(Calendar.MONTH);
            int day = c.get(Calendar.DAY_OF_MONTH);

            // Create a new instance of DatePickerDialog and return it
            return new DatePickerDialog(getActivity(), this, year, month, day);
        }

        public void onDateSet(DatePicker view, int year, int month, int day) 
        {   
            populateSetDate(year, month+1,day);
        }

I tried to change the variable to static so that it doesn't give me error. and then i did search on the web how fix this problem . Some did tell me that adding getActivity will fix the problem. but it still giving me the same error. anyone can help. Thanks

Answer 1

First make your method populateSetDate and variables non-static.

And in fragment:

 public void onDateSet(DatePicker view, int year, int month, int day) 
    {   
        ((RetrieveActivity)getActivity()).populateSetDate(year, month+1,day);
    }

A better solution would be to create an interface :

interface Callbacack{
    public void populateSetDate(int year,int month,int day);
}

Make you activity implement it:

public class RetrieveActivity extends Activity implements Callback

Inside fragment:

public static class DatePickerFragment extends DialogFragment
    implements DatePickerDialog.OnDateSetListener 
    {
    Callback callback;
    public void setCallback(Callback callback){
        this.callback = callback;
    }

And onDateSet

 public void onDateSet(DatePicker view, int year, int month, int day) 
        {   
            callback.populateSetDate(year, month+1,day);
        }