# 1。我想显示一个datepicker与当前日期预选(我使用butterknife注入)

  @OnClick(R.id.your_view) public void onClickYourView() {

    final Calendar myCalendar = Calendar.getInstance();
    DatePickerDialog.OnDateSetListener date = new DatePickerDialog.OnDateSetListener() {
      @Override
      public void onDateSet(DatePicker view, int year, int monthOfYear, int dayOfMonth) {
        // TODO Auto-generated method stub
        myCalendar.set(Calendar.YEAR, year);
        myCalendar.set(Calendar.MONTH, monthOfYear);
        myCalendar.set(Calendar.DAY_OF_MONTH, dayOfMonth);
        String myFormat = "dd MMMM yyyy"; // your format
        SimpleDateFormat sdf = new SimpleDateFormat(myFormat, Locale.getDefault());

        your_view.setText(sdf.format(myCalendar.getTime()));
      }

    };
    new DatePickerDialog(mContext, date, myCalendar.get(Calendar.YEAR), myCalendar.get(Calendar.MONTH), myCalendar.get(Calendar.DAY_OF_MONTH)).show();

  }

2. 如果您想预选日期，请将最后一部分替换为

new DatePickerDialog(mContext, date, 1990, 0, 1).show();

然后你可以使用myCalendar变量或直接在视图上的文本来获取它。

 selectDate.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                DatePickerDialog  mdiDialog =new DatePickerDialog(mContext,new DatePickerDialog.OnDateSetListener() {
                    @Override
                    public void onDateSet(DatePicker view, int year, int monthOfYear, int dayOfMonth) {
                        Toast.makeText(getApplicationContext(),year+ " "+monthOfYear+" "+dayOfMonth,Toast.LENGTH_LONG).show();


                    }
                }, year, month, date);
                mdiDialog.show();

            }

        });

我的类为show DatePicker。我可以使用EditText, TextView或按钮

import android.app.DatePickerDialog;
import android.content.Context;
import android.view.View;
import android.widget.DatePicker;
import android.widget.TextView;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.TimeZone;

public class TextViewDatePicker
        implements View.OnClickListener, DatePickerDialog.OnDateSetListener {
    public static final String DATE_SERVER_PATTERN = "yyyy-MM-dd";
    private DatePickerDialog mDatePickerDialog;
    private TextView mView;
    private Context mContext;
    private long mMinDate;
    private long mMaxDate;

    public TextViewDatePicker(Context context, TextView view) {
        this(context, view, 0, 0);
    }

    public TextViewDatePicker(Context context, TextView view, long minDate, long maxDate) {
        mView = view;
        mView.setOnClickListener(this);
        mView.setFocusable(false);

        mContext = context;
        mMinDate = minDate;
        mMaxDate = maxDate;
    }

    @Override
    public void onDateSet(DatePicker view, int year, int monthOfYear, int dayOfMonth) {
        Calendar calendar = Calendar.getInstance();
        calendar.set(Calendar.YEAR, year);
        calendar.set(Calendar.MONTH, monthOfYear);
        calendar.set(Calendar.DAY_OF_MONTH, dayOfMonth);
        Date date = calendar.getTime();

        SimpleDateFormat formatter = new SimpleDateFormat(DATE_SERVER_PATTERN);
        mView.setText(formatter.format(date));
    }

    @Override
    public void onClick(View v) {
        Calendar calendar = Calendar.getInstance(TimeZone.getDefault());
        mDatePickerDialog = new DatePickerDialog(mContext, this, calendar.get(Calendar.YEAR),
                calendar.get(Calendar.MONTH), calendar.get(Calendar.DAY_OF_MONTH));
        if (mMinDate != 0) {
            mDatePickerDialog.getDatePicker().setMinDate(mMinDate);
        }
        if (mMaxDate != 0) {
            mDatePickerDialog.getDatePicker().setMaxDate(mMaxDate);
        }
        mDatePickerDialog.show();
    }

    public DatePickerDialog getDatePickerDialog() {
        return mDatePickerDialog;
    }

    public void setMinDate(long minDate) {
        mMinDate = minDate;
    }

    public void setMaxDate(long maxDate) {
        mMaxDate = maxDate;
    }
}

使用

EditText myEditText = findViewById(R.id.myEditText);
TextViewDatePicker editTextDatePicker = new TextViewDatePicker(context, myEditText, minDate, maxDate);
//TextViewDatePicker editTextDatePicker = new TextViewDatePicker(context, myEditText); //without min date, max date

使用数据绑定:

<EditText
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:focusable="false"
  android:onClick="@{() -> viewModel.onDateEditTextClicked()}"
  android:hint="@string/hint_date"
  android:imeOptions="actionDone"
  android:inputType="none"
  android:maxLines="1"
  android:text="@={viewModel.filterDate}" />

(参见focusable, inputType和onClick)

在视图模型:

public void onDateEditTextClicked() {
    // do something
}

editText1.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            DatePickerDialog.OnDateSetListener dpd = new DatePickerDialog.OnDateSetListener() {
                @Override
                public void onDateSet(DatePicker view, int year, int monthOfYear,
                                      int dayOfMonth) {

                    int s = monthOfYear + 1;
                    String a = dayOfMonth + "/" + s + "/" + year;
                    editText1.setText(a);
                }
            };

            Time date = new Time();
            DatePickerDialog d = new DatePickerDialog(UpdateStore.this, dpd, date.year, date.month, date.monthDay);
            d.show();

        }
    });

下面是Material Date Picker的Kotlin扩展函数:

fun TextInputEditText.datePicker(fm:FragmentManager, tag: String) {

isFocusableInTouchMode = false
isClickable = true
isFocusable = false

val datePicker =
    MaterialDatePicker.Builder.datePicker()
        .setTitleText("Select Date")
        .build()


setOnClickListener {

    datePicker.show(fm,"tag")
}

datePicker.addOnPositiveButtonClickListener {
   setText(datePicker.headerText)
    Log.d("TAG", "datePicker: \n $it")
}}

用法:

在活动:

yourTextInputEditText.datePicker(supportFragmentManager,"tag")

在片段:

yourTextInputEditText.datePicker(requireActivity().supportFragmentManager,"tag")