实现功能

实现日期和时间选择的对话框，具体效果可看下图(以日期为例)

具体代码

1 日期对话框

1.1 xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:gravity="center">
    <DatePicker
        android:id="@+id/datePicker"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:calendarViewShown="false"
        android:datePickerMode="spinner"
        />
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:gravity="center"
        android:padding="10dp">
    <Button
        android:id="@+id/btn_date"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="选择日期"/>
    <Button
        android:id="@+id/btn_ok"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="确定"/>
    </LinearLayout>
    <TextView
        android:id="@+id/tv_date"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="尚未选择"
        android:textSize="20sp"/>
</LinearLayout>

1.2 Java

package com.example.learn;

import androidx.appcompat.app.AppCompatActivity;

import android.app.DatePickerDialog;
import android.os.Bundle;
import android.view.View;
import android.widget.DatePicker;
import android.widget.TextView;

import java.util.Calendar;

public class DatePickerActivity extends AppCompatActivity implements View.OnClickListener, DatePickerDialog.OnDateSetListener {
    private TextView tv;
    private DatePicker dp;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_date_picker);
        findViewById(R.id.btn_ok).setOnClickListener(this);
        findViewById(R.id.btn_date).setOnClickListener(this);
        tv=findViewById(R.id.tv_date);
        dp = findViewById(R.id.datePicker);
    }

    @Override
    public void onClick(View view) {
        switch(view.getId()){
            case R.id.btn_ok:
                String desc=String.format("%d年%d月%d日",dp.getYear(),dp.getMonth()+1,dp.getDayOfMonth());
                tv.setText(desc);
                break;
            case R.id.btn_date:
                //获取当前时间
                Calendar now = Calendar.getInstance();
                DatePickerDialog dpd = new DatePickerDialog(this,this,now.get(Calendar.YEAR),now.get(Calendar.MONTH),now.get(Calendar.DAY_OF_MONTH));
                //显示
                dpd.show();
                break;
        }
    }

    @Override
    public void onDateSet(DatePicker datePicker, int i, int i1, int i2) {
        String desc=String.format("%d年%d月%d日",i,i1+1,i2);
        tv.setText(desc);
    }
}

2 时间选择对话框

2.1 xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:gravity="center">
    <TimePicker
        android:id="@+id/timePicker"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:timePickerMode="spinner"
        />
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:gravity="center"
        android:padding="10dp">
        <Button
            android:id="@+id/btn_time"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="选择时间"/>
        <Button
            android:id="@+id/btn_ok"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="确定"/>
    </LinearLayout>
    <TextView
        android:id="@+id/tv_date"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="尚未选择"
        android:textSize="20sp"/>
</LinearLayout>

2.2 java

package com.example.learn;

import androidx.appcompat.app.AppCompatActivity;

import android.app.TimePickerDialog;
import android.os.Bundle;
import android.view.View;
import android.widget.DatePicker;
import android.widget.TextView;
import android.widget.TimePicker;

import java.util.Calendar;

public class TimePickerActivity extends AppCompatActivity implements View.OnClickListener, TimePickerDialog.OnTimeSetListener {
    private TextView tv;
    private TimePicker tp;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_time_picker);
        findViewById(R.id.btn_ok).setOnClickListener(this);
        findViewById(R.id.btn_time).setOnClickListener(this);
        tv=findViewById(R.id.tv_date);
        tp = findViewById(R.id.timePicker);
    }

    @Override
    public void onClick(View view) {
        switch(view.getId()){
            case R.id.btn_ok:
                String desc=String.format("%d时%d分",tp.getCurrentHour(),tp.getCurrentMinute());
                tv.setText(desc);
                break;
            case R.id.btn_time:
                //获取日历实例，包含日期和时分
                Calendar instance = Calendar.getInstance();
                //构建时间对话框
//                TimePickerDialog tpd = new TimePickerDialog(this,this,
//                        instance.get(Calendar.HOUR_OF_DAY),
//                        instance.get(Calendar.MINUTE),
//                        true);
                //添加样式
                TimePickerDialog tpd = new TimePickerDialog(this, android.R.style.Theme_Holo_Dialog,this,
                        instance.get(Calendar.HOUR_OF_DAY),
                        instance.get(Calendar.MINUTE),
                        true);
                tpd.show();
                break;
        }
    }

    @Override
    public void onTimeSet(TimePicker timePicker, int i, int i1) {
        String desc=String.format("%d时%d分",i,i1);
        tv.setText(desc);
    }
}