Custom Date Picker Dialog in Android Lollipop

问题

I want a date picker to show only Month and Year. I've customized the Date Picker to do so i.e., to remove 'day' field from the picker,but in Android Lollipop Am getting picker with Day, Month and Year. Following is my piece of code. Please help me to know the problem. Thanks in advance.

    try {
        Field f[] = mDatePicker.getClass().getDeclaredFields();
        for (Field field : f) {

            if (field.getName().equals("mDaySpinner") || field.getName().equals("mDayPicker")) {
                field.setAccessible(true);
                Object dayPicker = new Object();
                dayPicker = field.get(mDatePicker);
                ((View) dayPicker).setVisibility(View.GONE);
            }

        }
    } catch (SecurityException e) {
    } catch (IllegalArgumentException e) {
    } catch (IllegalAccessException e) {
    }

回答1:

Using reflection to find and hide UI elements is not really a great practice. In your case, it stopped working in lollipop because the mDaySpinner is now contained in an internal private static DatePickerSpinngerDelegate class within the DatePicker class.

I would recommend going through the view hierarchy to find and hide the day spinner element instead. I wrote the following code that works in lollipop:

if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
    int daySpinnerId = Resources.getSystem().getIdentifier("day", "id", "android");
    if (daySpinnerId != 0) {
        View daySpinner = datePicker.findViewById(daySpinnerId);
        if (daySpinner != null) {
            daySpinner.setVisibility(View.GONE);
        }
    }
}

回答2:

This is a basic example of a month picker, but can be easily adapted to pick also year and/or day (works also for older android versions):

public void initMonthPicker(){
dp_mes = (DatePicker) findViewById(R.id.dp_mes);

int year    = dp_mes.getYear();
int month   = dp_mes.getMonth();
int day     = dp_mes.getDayOfMonth();

dp_mes.init(year, month, day, new DatePicker.OnDateChangedListener() {
    @Override
    public void onDateChanged(DatePicker view, int year, int monthOfYear, int dayOfMonth) {
        month_i = monthOfYear + 1;
        Log.e("selected month:", Integer.toString(month_i));
     //Add whatever you need to handle Date changes
    }
});

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP){
    int daySpinnerId = Resources.getSystem().getIdentifier("day", "id", "android");
    if (daySpinnerId != 0)
    {
        View daySpinner = dp_mes.findViewById(daySpinnerId);
        if (daySpinner != null)
        {
            daySpinner.setVisibility(View.GONE);
        }
    }

    int monthSpinnerId = Resources.getSystem().getIdentifier("month", "id", "android");
    if (monthSpinnerId != 0)
    {
        View monthSpinner = dp_mes.findViewById(monthSpinnerId);
        if (monthSpinner != null)
        {
            monthSpinner.setVisibility(View.VISIBLE);
        }
    }

    int yearSpinnerId = Resources.getSystem().getIdentifier("year", "id", "android");
    if (yearSpinnerId != 0)
    {
        View yearSpinner = dp_mes.findViewById(yearSpinnerId);
        if (yearSpinner != null)
        {
            yearSpinner.setVisibility(View.GONE);
        }
    }
} else { //Older SDK versions
    Field f[] = dp_mes.getClass().getDeclaredFields();
    for (Field field : f)
    {
        if(field.getName().equals("mDayPicker") || field.getName().equals("mDaySpinner"))
        {
            field.setAccessible(true);
            Object dayPicker = null;
            try {
                dayPicker = field.get(dp_mes);
            } catch (IllegalAccessException e) {
                e.printStackTrace();
            }
            ((View) dayPicker).setVisibility(View.GONE);
        }

        if(field.getName().equals("mMonthPicker") || field.getName().equals("mMonthSpinner"))
        {
            field.setAccessible(true);
            Object monthPicker = null;
            try {
                monthPicker = field.get(dp_mes);
            } catch (IllegalAccessException e) {
                e.printStackTrace();
            }
            ((View) monthPicker).setVisibility(View.VISIBLE);
        }

        if(field.getName().equals("mYearPicker") || field.getName().equals("mYearSpinner"))
        {
            field.setAccessible(true);
            Object yearPicker = null;
            try {
                yearPicker = field.get(dp_mes);
            } catch (IllegalAccessException e) {
                e.printStackTrace();
            }
            ((View) yearPicker).setVisibility(View.GONE);
        }
    }
}

}

回答3:

Went ahead making a modified Date Picker called Simple Date picker ... have used the code similar to Date Picker just to show month and year

see https://github.com/resengupta/Month-Year-Date-Picker

SimpleDatePickerDialog.java class is responsible for showing the month and year number picker. SimpleDatePickerDelegate.java works to apply rules to the number pickers. SimpleDatePickerDialogFragment.java is a DialogFragment which wraps the alert dialog.

来源：https://stackoverflow.com/questions/26460682/custom-date-picker-dialog-in-android-lollipop