android中的DatePicker示例

import android.app.DatePickerDialog;
import android.app.Dialog;
import android.os.Bundle;
import android.widget.DatePicker;
import android.widget.Toast;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.fragment.app.DialogFragment;

import java.util.Calendar;

public class DatePickerFragment extends DialogFragment implements DatePickerDialog.OnDateSetListener {

    @NonNull
    @Override
    public Dialog onCreateDialog(@Nullable Bundle savedInstanceState) {
        // 获取当前日期
        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);

        // 创建一个DatePickerDialog实例并返回
        return new DatePickerDialog(getActivity(), this, year, month, day);
    }

    @Override
    public void onDateSet(DatePicker view, int year, int month, int dayOfMonth) {
        // 处理日期选择事件
        String selectedDate = year + "-" + (month + 1) + "-" + dayOfMonth;
        Toast.makeText(getActivity(), "Selected Date: " + selectedDate, Toast.LENGTH_SHORT).show();
    }
}

import android.os.Bundle;
import androidx.appcompat.app.AppCompatActivity;
import androidx.fragment.app.DialogFragment;
import android.view.View;
import android.widget.Button;

public class MainActivity extends AppCompatActivity {

    private Button datePickerButton;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        datePickerButton = findViewById(R.id.datePickerButton);
        datePickerButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                showDatePicker();
            }
        });
    }

    private void showDatePicker() {
        DialogFragment datePickerFragment = new DatePickerFragment();
        datePickerFragment.show(getSupportFragmentManager(), "datePicker");
    }
}