注释

app/src/main/java/net/micode/notes/ui/AlarmInitReceiver.java

@@ -34,19 +34,22 @@ public class AlarmInitReceiver extends BroadcastReceiver {
         NoteColumns.ID,
         NoteColumns.ALERTED_DATE
     };
-
+//对数据库的操作，调用标签ID和闹钟时间
     private static final int COLUMN_ID                = 0;
     private static final int COLUMN_ALERTED_DATE      = 1;
 
     @Override
     public void onReceive(Context context, Intent intent) {
         long currentDate = System.currentTimeMillis();
+        //System.currentTimeMillis()产生一个当前的毫秒
+        //这个毫秒就是自1970年1月1日0时起的毫秒数
         Cursor c = context.getContentResolver().query(Notes.CONTENT_NOTE_URI,
                 PROJECTION,
                 NoteColumns.ALERTED_DATE + ">? AND " + NoteColumns.TYPE + "=" + Notes.TYPE_NOTE,
                 new String[] { String.valueOf(currentDate) },
+                //将long变量currentData转化为字符串
                 null);
-
+//Cursor在这里的作用是通过查找数据库中的标签内容，找到和当前系统时间相等的标签
         if (c != null) {
             if (c.moveToFirst()) {
                 do {
@@ -62,4 +65,7 @@ public class AlarmInitReceiver extends BroadcastReceiver {
             c.close();
         }
     }
+    //然而通过网上查找资料发现，对于闹钟机制的启动，通常需要上面的几个步骤
+    //如新建Intent、PendingIntrnt以及AlarmManger等
+    //这里就是根据数据库里的闹钟时间创建一个闹钟机制
 }

app/src/main/java/net/micode/notes/ui/DateTimePicker.java

@@ -29,6 +29,8 @@ import android.widget.FrameLayout;
 import android.widget.NumberPicker;
 
 public class DateTimePicker extends FrameLayout {
+    //FrameLayout是布局模板之一
+    //所有的子元素全部在元素的右上方
 
     private static final boolean DEFAULT_ENABLE_STATE = true;
 
@@ -45,13 +47,15 @@ public class DateTimePicker extends FrameLayout {
     private static final int MINUT_SPINNER_MAX_VAL = 59;
     private static final int AMPM_SPINNER_MIN_VAL = 0;
     private static final int AMPM_SPINNER_MAX_VAL = 1;
-
+//初始化控件
     private final NumberPicker mDateSpinner;
     private final NumberPicker mHourSpinner;
     private final NumberPicker mMinuteSpinner;
     private final NumberPicker mAmPmSpinner;
+    //NumberPicker是数字选择器
+    //这里定义的四个变量全部是在设置闹钟时需要选择的变量（如日期、时、分、上午或者下午
     private Calendar mDate;
-
+//定义了Calendar类型的变量mDate,用于操作时间
     private String[] mDateDisplayValues = new String[DAYS_IN_ALL_WEEK];
 
     private boolean mIsAm;
@@ -71,23 +75,28 @@ public class DateTimePicker extends FrameLayout {
             updateDateControl();
             onDateTimeChanged();
         }
-    };
+    };//OnValueChangeListener,这是时间改变监听器，这里主要是对日期监听
+    //将现在的日期的值传递给mDate,updateDateControl是同步操作
 
     private NumberPicker.OnValueChangeListener mOnHourChangedListener = new NumberPicker.OnValueChangeListener() {
+        //这里是对小时的监听
         @Override
         public void onValueChange(NumberPicker picker, int oldVal, int newVal) {
             boolean isDateChanged = false;
             Calendar cal = Calendar.getInstance();
+            //声明一个Calendar的变量cal，便于后续操作
             if (!mIs24HourView) {
                 if (!mIsAm && oldVal == HOURS_IN_HALF_DAY - 1 && newVal == HOURS_IN_HALF_DAY) {
                     cal.setTimeInMillis(mDate.getTimeInMillis());
                     cal.add(Calendar.DAY_OF_YEAR, 1);
                     isDateChanged = true;
+                    //这里是对于12显示制时，凌晨11点和12点交替时对日期的更改
                 } else if (mIsAm && oldVal == HOURS_IN_HALF_DAY && newVal == HOURS_IN_HALF_DAY - 1) {
                     cal.setTimeInMillis(mDate.getTimeInMillis());
                     cal.add(Calendar.DAY_OF_YEAR, -1);
                     isDateChanged = true;
                 }
+                //这里是对于12小时制时，中午11点和12点交替时对日期的更改
                 if (oldVal == HOURS_IN_HALF_DAY - 1 && newVal == HOURS_IN_HALF_DAY ||
                         oldVal == HOURS_IN_HALF_DAY && newVal == HOURS_IN_HALF_DAY - 1) {
                     mIsAm = !mIsAm;
@@ -98,12 +107,13 @@ public class DateTimePicker extends FrameLayout {
                     cal.setTimeInMillis(mDate.getTimeInMillis());
                     cal.add(Calendar.DAY_OF_YEAR, 1);
                     isDateChanged = true;
+                    //这里是对于12小时制时，晚上11点和12点交替时对日期的更改
                 } else if (oldVal == 0 && newVal == HOURS_IN_ALL_DAY - 1) {
                     cal.setTimeInMillis(mDate.getTimeInMillis());
                     cal.add(Calendar.DAY_OF_YEAR, -1);
                     isDateChanged = true;
                 }
-            }
+            }//这里是对弈24
             int newHour = mHourSpinner.getValue() % HOURS_IN_HALF_DAY + (mIsAm ? 0 : HOURS_IN_HALF_DAY);
             mDate.set(Calendar.HOUR_OF_DAY, newHour);
             onDateTimeChanged();