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Question

我在我的应用程序中使用datePickerDialog。我在同一个onClickListener上设置了当前日期和textView

最初textView显示当前日期，当它侦听点击事件时，它会显示DatePickerDialog

我的问题是什么？

当我点按textView时，它显示DatePicker 当前日期，然后我设置了任何日期，现在可以在textView 上看到新日期，但我每次点击textView时都会在datePickerDialog中显示当前日期，我希望datepicker 更新 {{1}上的日期也。

这是我的datePickerDialog代码段

Activity.java

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我还将final Calendar c = Calendar.getInstance(); mYear = c.get(Calendar.YEAR); mMonth = c.get(Calendar.MONTH); mDay = c.get(Calendar.DAY_OF_MONTH); //format of the current date String currDate = new SimpleDateFormat("MM/dd/yyyy").format(new Date()); //set current date on textView dateView = (TextView) findViewById(R.id.date_view); dateView.setText(currDate); dateView.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { DatePickerDialog dpd = new DatePickerDialog(TRTimeReminder.this, new DatePickerDialog.OnDateSetListener() { @Override public void onDateSet(DatePicker view, int year, int month, int day) { c.set(year, month, day); String date = new SimpleDateFormat("MM/dd/yyyy").format(c.getTime()); dateView.setText(date); } }, mYear, mMonth, mDay); dpd.show(); } });更新为DatePickerDialog(TRTimeReminder.this,.....,mYear, mMonth, mDay)

其中DatePickerDialog(TRTimeReminder.this,....., y, m, d)是我在int y, m, d方法中定义为onDateSet()的变量，但是当我点击textView时，它会显示初始化日期 JAN 1 1900

Answer 1

您正在使用dpd初始化mYear, mMonth, mDay，据我所知，您永远不会更新这些内容。

有关评论的更新：

在初始化新Calendar c时从DatePickerDialog提取数据，而不是使用存储的值。

DatePickerDialog dpd = new DatePickerDialog(TRTimeReminder.this,
  new DatePickerDialog.OnDateSetListener() {
        @Override
        Public void onDateSet(DatePicker view, int year, int month, int day) {
        c.set(year, month, day);
        String date = new SimpleDateFormat("MM/dd/yyyy").format(c.getTime());
        dateView.setText(date);
        }

        c.get(Calender.YEAR); // I forgot if you need the ; here when using Java
        c.get(Calender.MONTH;
        c.get(Calender.DAY_OF_MONTH);
});

Answer 2

由于以下几个原因，我认为您的代码不是优化或正确的：

每次点击活动都有新的日期选择器实例。
我认为你甚至不会解雇之前的日期选择器，即使这样，这段代码也很糟糕。
设置当前日期后，您永远不会使用新值重新初始化成员变量mYear，mMonth，mDay。

修复您的代码 -

DatePickerDialog dpd = new DatePickerDialog(TRTimeReminder.this,
  new DatePickerDialog.OnDateSetListener() {
        @Override
        Public void onDateSet(DatePicker view, int year, int month, int day) {
            mYear = year;
            mMonth = month;
            mDay = day;
           // Perform your operation
        }

}, mYear, mMonth, mDay);

根据我的建议，我更愿意实现以下代码： -

public class CustomDatePicker extends DialogFragment implements DatePickerDialog.OnDateSetListener {

    private static final String CUSTOM_DIALOG_TAG="custom_dialog";

    public static void showDialog(FragmentManager fm){
        FragmentTransaction ft = fm.beginTransaction();
        CustomDatePicker mPrveInstance = (CustomDatePicker)fm.findFragmentByTag(CUSTOM_DIALOG_TAG);
        if (mPrveInstance != null) {
            ft.remove(mPrveInstance);
        }
        ft.addToBackStack(null);
        // Create and show the dialog.
        CustomDatePicker datePicker = new CustomDatePicker();
        datePicker.show(ft, CUSTOM_DIALOG_TAG);
    }
    @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);
    }

    @Override
    public void onDateSet(DatePicker view, int year, int monthOfYear, int dayOfMonth) {
        // Create Interface and send callback to activity to call show
        // Avoid exposing dialog fragment instance to activity
        Calendar.getInstance().set(year, month, day);
    }

}

从Activity直接调用show方法，只要你想显示它。

// CustomDatePicker.showDialog(getFragmentManager());

Answer 3

在用户设置日期后调用OnDateSet。如果要在对话框中显示上一个日期，必须首先调用onCreateDialog并设置日期。请参阅下面的代码示例：

@Override
public Dialog onCreateDialog(Bundle savedInstanceState)
{
int year = 0;
int month = 0;
int day = 0;

// get previous date if available
String dateFormatted = dateView.getText();
Log.i(TAG, "What is the user's date " + dateFormatted);

if (dateFormatted == null || dateFormatted.isEmpty())
{
  // Use the current date as the default date in the picker
  final Calendar c = Calendar.getInstance();
  year = c.get(Calendar.YEAR);
  Log.i(TAG, "what is the phone's year: " + year);
  month = c.get(Calendar.MONTH);
  Log.i(TAG, "what is the phone's month: " + month);
  day = c.get(Calendar.DAY_OF_MONTH);
  Log.i(TAG, "what is the phone's day: " + day);
} else
{
  day = Integer.parseInt(dateFormatted.substring(0, 2));
  Log.i(TAG, "what is the user's day: " + day);
  month = Integer.parseInt(dateFormatted.substring(3, 5));
  // Correct month to 0-11 format from 1-12 format
  month = month - 1;
  Log.i(TAG, "what is the user's month: " + month);
  year = Integer.parseInt(dateFormatted.substring(6, 10));
  Log.i(TAG, "what is the user's year: " + year);
}

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

N.B。我正在使用DialogFragment实现DatePickerDialog.OnDateSetListener。因此，您可能需要将getActivity更改为此。我认为它会起作用。

然后使用onDateSet：

public void onDateSet(DatePicker view, int year, int month, int day)
{
// Do something with the date chosen by the user
Time time = new Time();
time.set(day, month, year);
String date = time.format("%d-%m-%Y");
Log.i(TAG, "The date you are setting: " + date);
dateView.setText(date);
Log.i(TAG, "You have set the date to: " + date);
}

Answer 4

要在取消时重置日期选择器，请点击：

在日期选择器上添加onDismissListner
在onDismissListener内部，调用updateData方法

示例：

datePicker.setOnDismissListener((dialog) -> {
    datePicker.updateData(Year, Month, Date);
}

注意：：您可能会认为用户单击“确定”，此代码将产生问题。理想情况下不。在onDateSet中调用updateData时，不会有任何问题。

参考： https://stackoverflow.com/a/57703547/1994950

DatePickerDialog重置Android中的日期

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4 个答案: