Android开发，设置闹钟提醒

1.涉及到的技术点

1. 使用 MediaPlayer播放音频
2. 使用AnalogClock 显示当前时钟
3. 使用DatePickerDialog 日期选择框，设置提醒日期
4. 使用TimePickerDialog时间选择框，设置提醒时间

2. 闹铃设置页面实现

1. 编写设置闹铃的布局页面 activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.appcompat.widget.LinearLayoutCompat 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:gravity="center_horizontal"
    android:orientation="vertical">

    <AnalogClock
        android:id="@+id/analogClock"
        android:layout_width="131dp"
        android:layout_height="107dp"
        android:layout_marginTop="30dp" />

    <Button
        android:id="@+id/btn_time"
        android:layout_width="219dp"
        android:layout_height="54dp"
        android:layout_marginTop="20dp"
        android:text="选择时间" />

    <TextView
        android:id="@+id/tv_date"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="20dp"
        android:gravity="center"
        android:text="日期" />

    <TextView
        android:id="@+id/tv_time"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="20dp"
        android:gravity="center"
        android:text="时间" />

    <Button
        android:id="@+id/btn_date"
        android:layout_width="219dp"
        android:layout_height="51dp"
        android:layout_marginTop="20dp"
        android:text="选择日期" />


    <androidx.appcompat.widget.SwitchCompat
        android:id="@+id/sw_set"
        android:layout_width="wrap_content"
        android:layout_height="51dp"
        android:layout_marginTop="20dp" />


    <TextView
        android:id="@+id/tv_status"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="20dp"
        android:gravity="center"
        android:text="时间" />

</androidx.appcompat.widget.LinearLayoutCompat>

布局效果图

2. 当点击【选择时间】按钮的时候，弹出时间选择对话框

 bt_time.setOnClickListener(new View.OnClickListener() {
    
    
            @Override
            public void onClick(View view) {
    
    
                new TimePickerDialog(MainActivity.this,mOnTimeSetListener,hour,minute,true).show();
            }
        });

3. mOnTimeSetListener 的回调监听

 //时间选择回调监听器
    TimePickerDialog.OnTimeSetListener mOnTimeSetListener = new TimePickerDialog.OnTimeSetListener() {
    
    
        @Override
        public void onTimeSet(TimePicker timePicker, int hourOfDay, int minute) {
    
    

            MainActivity.this.hour = hourOfDay;
            MainActivity.this.minute = minute;

            tv_time.setText(hourOfDay + "时" + minute + "分");
        }
    };

实现效果如下

4. 当点击【选择日期】按钮的时候，弹出日期选择对话框

bt_date.setOnClickListener(new View.OnClickListener() {
    
    
            @Override
            public void onClick(View view) {
    
    
                new DatePickerDialog(MainActivity.this,mOnDateSetListener,year,month,day).show();
            }
        });

5. mOnDateSetListener 回调监听

    //日期选择回调监听器
    DatePickerDialog.OnDateSetListener mOnDateSetListener = new DatePickerDialog.OnDateSetListener() {
    
    
        @Override
        public void onDateSet(DatePicker datePicker, int i, int month, int day) {
    
    
            MainActivity.this.year = year;
            MainActivity.this.month = month;
            MainActivity.this.day = day;

            tv_date.setText(year + "年" + (month + 1) + "月" + day + "日");
        }
    };

这里注意：month 月份要加1 ，在我们习惯中，默认从1开始，外国人喜欢从0开始（因为计算机是英文编程，存在一些差异~）

实现效果如下

6. 滑动开关，设置闹铃

sw_set.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
    
    
            @Override
            public void onCheckedChanged(CompoundButton compoundButton, boolean b) {
    
    
                if (b){
    
    
                    setAlarm();
                }else {
    
    
                    cancelAlarm();
                }
            }
        });

setAlarm方法

    /**
     * 设置闹铃
     */
    private void setAlarm() {
    
    
        ca = Calendar.getInstance();
        ca.set(year, month, day, hour, minute, 0);
        //跳转到闹铃页面
        Intent intent = new Intent(MainActivity.this, ALMActivity.class);
        PendingIntent pi = PendingIntent.getActivity(MainActivity.this, 0, intent, 0);
        AlarmManager am = (AlarmManager) getSystemService(ALARM_SERVICE);
        am.set(AlarmManager.RTC_WAKEUP, ca.getTimeInMillis(), pi);
        Toast.makeText(this, "闹钟已设置", Toast.LENGTH_SHORT).show();
        tv_status.setText("闹钟时间：" + year + "年" + (month + 1) + "月" + day + "日" + hour + "时" + minute + "分");

    }

cancelAlarm 方法

    /**
     * 取消闹铃
     * */

    private void cancelAlarm() {
    
    
        Intent intent = new Intent(MainActivity.this, ALMActivity.class);
        PendingIntent pi = PendingIntent.getActivity(MainActivity.this, 0, intent, 0);
        AlarmManager am = (AlarmManager) getSystemService(ALARM_SERVICE);
        am.cancel(pi);
        Toast.makeText(this, "闹钟已取消", Toast.LENGTH_SHORT).show();
        tv_status.setText("not set");
    }

7. 闹铃设置页面整个代码实现过程

public class MainActivity extends AppCompatActivity {
    
    
    Button bt_date, bt_time;
    TextView tv_date, tv_time, tv_status;
    SwitchCompat sw_set;
    int year, month, day, hour, minute;
    Calendar ca = Calendar.getInstance();


    //日期选择回调监听器
    DatePickerDialog.OnDateSetListener mOnDateSetListener = new DatePickerDialog.OnDateSetListener() {
    
    
        @Override
        public void onDateSet(DatePicker datePicker, int i, int month, int day) {
    
    
            MainActivity.this.year = year;
            MainActivity.this.month = month;
            MainActivity.this.day = day;

            tv_date.setText(year + "年" + (month + 1) + "月" + day + "日");
        }
    };


    //时间选择回调监听器
    TimePickerDialog.OnTimeSetListener mOnTimeSetListener = new TimePickerDialog.OnTimeSetListener() {
    
    
        @Override
        public void onTimeSet(TimePicker timePicker, int hourOfDay, int minute) {
    
    

            MainActivity.this.hour = hourOfDay;
            MainActivity.this.minute = minute;

            tv_time.setText(hourOfDay + "时" + minute + "分");
        }
    };


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

        //初始化控件
        bt_date =findViewById(R.id.btn_date);
        bt_time =findViewById(R.id.btn_time);
        sw_set =findViewById(R.id.sw_set);
        tv_date =findViewById(R.id.tv_date);
        tv_time =findViewById(R.id.tv_time);
        tv_status =findViewById(R.id.tv_status);


        //获取当前时间
        year =ca.get(Calendar.YEAR);
        month =ca.get(Calendar.MONTH);
        day =ca.get(Calendar.DAY_OF_MONTH);
        hour =ca.get(Calendar.HOUR_OF_DAY);
        minute =ca.get(Calendar.MINUTE);
        bt_date.setOnClickListener(new View.OnClickListener() {
    
    
            @Override
            public void onClick(View view) {
    
    
                new DatePickerDialog(MainActivity.this,mOnDateSetListener,year,month,day).show();
            }
        });

        bt_time.setOnClickListener(new View.OnClickListener() {
    
    
            @Override
            public void onClick(View view) {
    
    
                new TimePickerDialog(MainActivity.this,mOnTimeSetListener,hour,minute,true).show();
            }
        });

        sw_set.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
    
    
            @Override
            public void onCheckedChanged(CompoundButton compoundButton, boolean b) {
    
    
                if (b){
    
    
                    setAlarm();
                }else {
    
    
                    cancelAlarm();
                }
            }
        });

    }

    /**
     * 设置闹铃
     */
    private void setAlarm() {
    
    
        ca = Calendar.getInstance();
        ca.set(year, month, day, hour, minute, 0);
        Intent intent = new Intent(MainActivity.this, ALMActivity.class);
        PendingIntent pi = PendingIntent.getActivity(MainActivity.this, 0, intent, 0);
        AlarmManager am = (AlarmManager) getSystemService(ALARM_SERVICE);
        am.set(AlarmManager.RTC_WAKEUP, ca.getTimeInMillis(), pi);
        Toast.makeText(this, "闹钟已设置", Toast.LENGTH_SHORT).show();
        tv_status.setText("闹钟时间：" + year + "年" + (month + 1) + "月" + day + "日" + hour + "时" + minute + "分");

    }

    /**
     * 取消闹铃
     * */

    private void cancelAlarm() {
    
    
        Intent intent = new Intent(MainActivity.this, ALMActivity.class);
        PendingIntent pi = PendingIntent.getActivity(MainActivity.this, 0, intent, 0);
        AlarmManager am = (AlarmManager) getSystemService(ALARM_SERVICE);
        am.cancel(pi);
        Toast.makeText(this, "闹钟已取消", Toast.LENGTH_SHORT).show();
        tv_status.setText("not set");
    }
}

3. 响铃页面（ALMActivity）实现

当我们在闹铃设置界面设置闹铃时间+日期之后，当时间达到闹铃设置的时间，就跳转到闹铃页面

1. 响铃页面布局activity_almactivity.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.appcompat.widget.LinearLayoutCompat 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"
    tools:context=".ALMActivity">


    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:padding="30dp"
        android:text="闹铃启动啦！！！"
        android:textSize="30sp" />
</androidx.appcompat.widget.LinearLayoutCompat>

这里布局很简单，就简单显示一句话。闹铃页面重点是在于播放音频，达到提醒用户的效果

2. ALMActivity.java 页面代码实现

public class ALMActivity extends AppCompatActivity {
    
    
    MediaPlayer mMediaPlayer;

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

        try {
    
    
             // 初始化 MediaPlayer
            mMediaPlayer = new MediaPlayer();
             // 设置数据源
            mMediaPlayer = MediaPlayer.create(this, R.raw.music);
            // 获取 AudioManager 服务
            AudioManager audioManager = (AudioManager) getSystemService(AUDIO_SERVICE);
             //这行代码检查 STREAM_ALARM 音频流的音量是否不为0。如果音量为0，表示用户可能已经将闹钟声音静音了，此时不会播放音频
            if (audioManager.getStreamVolume(AudioManager.STREAM_ALARM) != 0) {
    
    
              // 设置音频循环播放
                mMediaPlayer.setLooping(true);
                // 开始播放音频
                mMediaPlayer.start();
            }
        } catch (Exception e) {
    
    
            e.printStackTrace();
        }


        //弹出对话框
        new AlertDialog.Builder(this).setTitle("闹钟提醒").setMessage("这是闹铃提醒的内容")
                .setCancelable(false)
                .setPositiveButton("确定", new DialogInterface.OnClickListener() {
    
    
                    @Override
                    public void onClick(DialogInterface dialogInterface, int i) {
    
    
                       //释放 MediaPlayer 资源
                        mMediaPlayer.release();
                        mMediaPlayer= null;
                        finish();
                    }
                }).show();
    }
}

在这里使用MediaPlayer来播放音频，代码都写了非常想起的注释，就不单独讲啦

这里注意：音频文件放在res->raw下，默认raw是没有这个文件夹的，新建文件夹就好啦，如下图所示

4. 运行效果