Android的DialogFragment - 获取参考日期选择器 [英] Android DialogFragment - Get reference to date picker

问题描述

Android的文档告诉我们实现像这样日期选择器，延长DialogFragment：

The Android docs tell us to implement date pickers like so, extending DialogFragment:

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) {
        // Do something with the date chosen by the user
    }
}

然后显示在我们的活动日期选取器对话框中，我们调用这个方法：

And then to display the date picker dialog in our Activity, we call this method:

public void showDatePickerDialog(View v) {
    DialogFragment newFragment = new DatePickerFragment();
    newFragment.show(getSupportFragmentManager(), "datePicker");
}

我需要知道的是，我如何才能在对话框中使用，这样我可以用的方法，如.setMinDate（）和.setMaxDate（）的实际日期选取器的参考是什么？有什么建议？

What I need to know is, how do I get a reference to the actual date picker used in the dialog so that I may use methods such as .setMinDate() and .setMaxDate()? Any suggestions?

推荐答案

我整理了这一点，与此<一个帮助href=\"http://stackoverflow.com/questions/8456143/dialogfragment-getdialog-returns-null\">StackOverflow回答：

I sorted this out with the help of this StackOverflow answer:

public void showDatePickerDialog() {
    DialogFragment newFragment = new DatePickerFragment();
    newFragment.show(getFragmentManager(), "datePicker");
    getFragmentManager().executePendingTransactions();     // commits the show method from above
    DatePickerDialog dialog = (DatePickerDialog) newFragment.getDialog();
    DatePicker datePicker = (DatePicker) dialog.getDatePicker();
    Date now = new Date();
    datePicker.setMaxDate(now.getTime());
}

您需要调用 .executePendingTransactions（）的片段管理器停止被异步添加对话框片段，否则 getDialog（）方法给出了一个空指针异常。

You need to call .executePendingTransactions()on the fragment manager to stop the dialog fragment being added asynchronously, otherwise the getDialog() method gives a null pointer exception.

我把它放在这里，将来任何人谁可能有这个问题。

I am putting it in here for anyone in the future who may have this problem.

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