Question

我按照此处的说明操作：https://developer.android.com/guide/topics/ui/controls/pickers.html

我向下滚动到“创建日期选择器”并将此代码复制粘贴到名为TargetPage的文件中：

DisplayText

然后我在DatePickerFragment.java：

中创建了此按钮

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
    }
}

并将此代码添加到activity_front_page.xml类：

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/pick_date"
    android:onClick="showDatePickerDialog" />

但它是说DatePickerFramegent没有定义？

我刚开始使用Android工作室并为Andriod开发。我想要的是日期选择器（如果您访问上面提供的链接，它的图片显示在屏幕顶部附近）。知道如何解决这个问题吗？

Answer 1

当你使用android.support.v4.app.DialogFragment时，你应该传递给show（）一个android.support.v4.app.FragmentManager的实例，可以使用getSupportFragmentManager（）调用查询

Answer 2

尝试以下代码，看看是否有帮助：

Activity activity = getActivity;
DatePickerDialog datePickerDialog = new DatePickerDialog(activity, AlertDialog.THEME_HOLO_LIGHT,
                new DatePickerDialog.OnDateSetListener() {

                    @Override
                    public void onDateSet(DatePicker view, int year, int monthOfYear, int dayOfMonth) {

                }, year, mm, dd);
        datePickerDialog.show();

Answer 3

您需要FragmentTransaction而不是getSupportFragmentManager()

public void showDatePickerDialog(View v) {
FragmentTransaction ft = getSupportFragmentManager().beginTransaction();

DialogFragment newFragment = new DatePickerFragment();
newFragment.show(ft, "datePicker");
}

如何在Android Studio中正确创建日期选择器？

3 个答案: