From 1832870656330950b006a72cade173fc549b56d8 Mon Sep 17 00:00:00 2001
From: 15225468927 <407245071@qq.com>
Date: Fri, 21 Apr 2023 10:15:48 +0800
Subject: [PATCH] =?UTF-8?q?=E4=BB=A3=E7=A0=81=E6=B3=A8=E9=87=8A=5F?=
 =?UTF-8?q?=E5=88=98=E7=BF=B1=E7=BF=94/AlarmAlertActivity.java?=
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---
 .../AlarmAlertActivity.java                   | 61 +++++++++++++++++++
 1 file changed, 61 insertions(+)
 create mode 100644 代码注释_刘翱翔/AlarmAlertActivity.java

diff --git a/代码注释_刘翱翔/AlarmAlertActivity.java b/代码注释_刘翱翔/AlarmAlertActivity.java
new file mode 100644
index 0000000..b0d38e8
--- /dev/null
+++ b/代码注释_刘翱翔/AlarmAlertActivity.java
@@ -0,0 +1,61 @@
+### AlarmInitReceiver.java
+
+```java
+package net.micode.notes.ui;
+ 
+import android.app.AlarmManager;
+import android.app.PendingIntent;
+import android.content.BroadcastReceiver;
+import android.content.ContentUris;
+import android.content.Context;
+import android.content.Intent;
+import android.database.Cursor;
+ 
+import net.micode.notes.data.Notes;
+import net.micode.notes.data.Notes.NoteColumns;
+ 
+ 
+public class AlarmInitReceiver extends BroadcastReceiver {
+ 
+    private static final String [] PROJECTION = new String [] {
+        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()产生一个当前的时间,以毫秒为单位
+        //这个毫秒其实就是自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currentDate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 {
+                    long alertDate = c.getLong(COLUMN_ALERTED_DATE);
+                    Intent sender = new Intent(context, AlarmReceiver.class);
+                    sender.setData(ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, c.getLong(COLUMN_ID)));
+                    PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 0, sender, 0);
+                    AlarmManager alermManager = (AlarmManager) context
+                            .getSystemService(Context.ALARM_SERVICE);
+                    alermManager.set(AlarmManager.RTC_WAKEUP, alertDate, pendingIntent);
+                } while (c.moveToNext());
+            }
+            c.close();
+        }
+        //闹钟机制的启动，通常需要几个步骤
+        //新建Intent、PendingIntent以及AlarmManager等
+        //这里就是根据数据库里的闹钟时间创建一个闹钟机制
+    }
+}
+```
+