appday2

DatePicker和TimePicker的使用
这是layout的代码

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<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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:id="@+id/main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <ScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintRight_toRightOf="parent">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="vertical">

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:id="@+id/textView"
                android:text="Large Text"
                android:textAppearance="?android:attr/textAppearanceLarge"/>

            <DatePicker
                android:id="@+id/datePicker"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:endYear="2030"
                android:startYear="1970" />

            <TimePicker
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:id="@+id/timePicker" />
        </LinearLayout>
    </ScrollView>
</androidx.constraintlayout.widget.ConstraintLayout>

这是activity的代码

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package com.example.day2;

import android.os.Bundle;
import android.widget.DatePicker;
import android.widget.TextView;
import android.widget.TimePicker;

import androidx.activity.EdgeToEdge;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.graphics.Insets;
import androidx.core.view.ViewCompat;
import androidx.core.view.WindowInsetsCompat;

import java.util.Calendar;

public class MainActivity extends AppCompatActivity {
    private TextView textView;
    private DatePicker datePicker;
    private TimePicker timePicker;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        EdgeToEdge.enable(this);
        setContentView(R.layout.activity_main);
        textView = this.findViewById(R.id.textView);
        datePicker = this.findViewById(R.id.datePicker);
        timePicker = this.findViewById(R.id.timePicker);
        Calendar calendar = Calendar.getInstance(); // 获得当前的日期和时间
        int year = calendar.get(Calendar.YEAR);
        int month = calendar.get(Calendar.MONTH);
        int day = calendar.get(Calendar.DAY_OF_MONTH);
        int hour = calendar.get(Calendar.HOUR);
        int minute = calendar.get(Calendar.MINUTE);

        datePicker.init(year, month, day, new DatePicker.OnDateChangedListener() {
            @Override
            public void onDateChanged(DatePicker view, int year, int monthOfYear, int dayOfMonth) {
                updateTextView();
            }
        });
        timePicker.setIs24HourView(false);
        timePicker.setCurrentHour(hour);
        timePicker.setCurrentMinute(minute);
        timePicker.setOnTimeChangedListener(new TimePicker.OnTimeChangedListener() {
            @Override
            public void onTimeChanged(TimePicker view, int hourOfDay, int minute) {
                updateTextView();
            }
        });
        textView.setText(year+"/"+month+"/"+day+"    "+hour+":"+minute);
    }

    public void updateTextView() {
        String str_hour = "", str_minute = "";
        int year = datePicker.getYear();
        int month = datePicker.getMonth();
        int day = datePicker.getDayOfMonth();
        int hour = timePicker.getHour();
        if (hour >= 12) {
            hour -= 12;
        }
        if (hour < 10) {
            str_hour = "0" + hour;
        } else {
            str_hour = hour + "";
        }
        int minute = timePicker.getMinute();
        if (minute < 10) {
            str_minute = "0" + minute;
        } else {
            str_minute = minute + "";
        }
        String str = Integer.toString(year) + "/" + Integer.toString(month + 1) + "/" + Integer.toString(day) + "    " + str_hour + ":" + str_minute;
        textView.setText(str); // 更新TextView的文本
    }
}

约束布局，相对布局，线性布局，滚动视图的使用（注意要在new的时候new对应的）
1.约束布局

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<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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:id="@+id/main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="TextView"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Button
        android:id="@+id/button1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Button"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/textView" />

    <ImageView
        android:id="@+id/imageView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/button1"
        app:srcCompat="?attr/actionModePasteDrawable"
        tools:srcCompat="@tools:sample/avatars[2]" />

    <Button
        android:id="@+id/button2"
        android:layout_width="190dp"
        android:layout_height="180dp"
        android:text="Button"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/imageView" />
</androidx.constraintlayout.widget.ConstraintLayout>

相对布局 

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<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:id="@+id/textView3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_marginLeft="8dp"
        android:layout_marginTop="8dp"
        android:text="请输入信息"
        android:textAppearance="?android:attr/textAppearanceLarge"/>
    <EditText
        android:id="@+id/editTextText2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/textView3"
        android:layout_marginLeft="8dp"
        android:layout_marginTop="8dp"
        android:ems="10"
        android:inputType="text" />
    <requestFocus/>

    <Button
        android:id="@+id/button4"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/editTextText2"
        android:layout_alignParentRight="true"
        android:layout_marginTop="8dp"
        android:layout_marginRight="8dp"
        android:text="确定" />

    <Button
        android:id="@+id/button5"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/editTextText2"
        android:layout_alignBaseline="@+id/button4"
        android:layout_alignBottom="@+id/button4"
        android:layout_toLeftOf="@+id/button4"
        android:text="取消" />
</RelativeLayout>

线性布局 

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<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Button" />

    <Button
        android:id="@+id/button3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Button" />
</LinearLayout>

滚动视图 

点击查看代码

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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">

    <ScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_marginStart="4dp"
        android:layout_marginTop="4dp"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical"
            android:padding="4dp">

            <TextView
                android:id="@+id/textView2"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:text="TextView" />

            <Button
                android:id="@+id/button7"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:text="Button" />

            <CalendarView
                android:id="@+id/calendarView"
                android:layout_width="match_parent"
                android:layout_height="wrap_content" />

            <Button
                android:id="@+id/button8"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:text="Button" />
        </LinearLayout>

    </ScrollView>

</androidx.constraintlayout.widget.ConstraintLayout>