How to make a DatePicker with DialogFragment and FragmentManager?

问题

So I have been at this for a while, and I cannot seem to figure it out. I am fairly new at Android development, so bear with me please. I wasn't too familiar with creating a Datepicker and I learned to do it the deprecated way just to get the hang of it. Used this tutorial to get me up to speed:

http://developer.android.com/resources/tutorials/views/hello-datepicker.html

But now I need to change it, mainly to not use deprecated code, so I looked all around, and I found 2 tutorials, mainly this one though:

http://www.kylebeal.com/2011/11/android-datepickerdialog-and-the-dialogfragment/

Problem is, there is code that does not make sense. Mainly this part:

//create new DateDialogFragment
DateDialogFragment ddf = DateDialogFragment.newInstance(this, R.string.set_date, date);

ddf.setDateDialogFragmentListener(new DateDialogFragmentListener() {

    @Override
    public void dateDialogFragmentDateSet(Calendar date) {
        // update the fragment
        mDateDetailFragment.updateDate(date);
    }
});

ddf.show(getSupportFragmentManager(), "date picker dialog fragment");

That is suppose to be what is running in the activity class that it runs in. So I kind of get whats happening throughout the rest of the code, and feel free to look at the rest as it will probably help. The code is essentially following almost the same route as the original showDialog() code. Implementing DatePickerDialog.onDateSetListener, and returning a new DatePickerDialog, with the obvious exception thats its using a DialogFragment. But that is where I have gotten lost.

Part of the reason is because I am not really sure where onCreateDialog() returns that new DatePickerDialog. If you look at the code I said does not make sense, both mDateDetailFragment and getSupportFragmentManager() were never instantiated or appeared anywhere else, so I cannot get the tutorial code to even work. The Android Doc also mentions that instead of using showDialog() I should be using both DialogFragment and FragmentManager, which is also not done here. Only DialogFragment.

So like the title, how exactly can I make a DatPicker in the non-depracted form? I would please ask to NOT send me to a link and just say look here. I have done that. Believe me. If not, at least explain what I have missed that makes this make sense. Also, if anyone can actually tell me where the onCreateDialog() method sends the DatePickerDialog, that would be extremely helpful as well. I am just trying to make sense of all this, rather than copy and paste code (not that it works anyways). Thanks a lot for taking the time out to read this, and if any clarifications needed, please ask.

回答1:

Going in order of your post... \

1) the onCreateDialog returns the dialog to the DialogFragment.

2) I don't know about the mDateDetailFragment.updateDate(date); line... I think he might have left some code out. EDIT Found it, it's in one of the classes in the zip file for his complete demo.

3) You are using the fragment manager (it's the getSupportFragmentManager() part):

ddf.show(getSupportFragmentManager(), "date picker dialog fragment");

Ok, that said, here's how I've done it (I'm using a DateSlider, but subbing in a Datepicker in it's place should be simple enough for you).

In the fragment/activity calling the DialogFragment:

DialogFragment newFragment = new DateDialog();
newFragment.show(getFragmentManager(), "dialog");

And my DialogFragment:

public class DateDialog extends DialogFragment {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
    }
    private DateSlider.OnDateSetListener mDateSetListener = new DateSlider.OnDateSetListener() {
        public void onDateSet(DateSlider view, Calendar selectedDate) {
            MemberAddFragment.startTxt.setText(String.format("%tB %te, %tY", selectedDate, selectedDate, selectedDate));
        }
    };

    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        final Calendar c = Calendar.getInstance();  // Get calendar instance to use in DateSlider
        return new AlternativeDateSlider(getActivity(),mDateSetListener,c,null,null);  // return DateSlider dialog to DialogFragment
    }
}

Hope this helps clear up your confusion.

回答2:

I know this question is mine and already has an answer. But I thought I'd add my own answer to others looking for help on this same issue. I have simplified the example code that I provided above into only 2 classes. Kbeal, who was gracious enough to provide the tutorial did a great job, but it was too bloated with information that was not even necessary. So using what I knew about dialogs and what I learned from what I could understand from the Kbeal's tutorial as well as the research I did on fragments, I have provided my implementation from a DatePickerDialog on my GitHub.

https://github.com/Zeroe31890/DateDialogFragment

All you honestly have to do is run it straight after only copy and pasting the 2 classes, the single layout, and modifying the Android Manifest file. Much easier than any of the other tutorials. Oh and if anybody sees anything that can be done better on it please do. Enjoy!

回答3:

Author of the post here: Sounds like you have it all figured out. I replied to your questions on my post before finding this though Barak does a fine job of answering them. If you haven't done so already download the complete source for the example app. I think it will help fill any missing blanks you still have.

来源：https://stackoverflow.com/questions/11008154/how-to-make-a-datepicker-with-dialogfragment-and-fragmentmanager

标签

android

android-fragments

android-dialogfragment

android-datepicker