代码注释

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

@@ -41,57 +41,59 @@ import java.io.IOException;
 
 
 public class AlarmAlertActivity extends Activity implements OnClickListener, OnDismissListener {
-    private long mNoteId;
+    private long mNoteId;   //文本再数据库存储中的id号
-    private String mSnippet;
+    private String mSnippet;    //闹钟提醒时的文字
     private static final int SNIPPET_PREW_MAX_LEN = 60;
     MediaPlayer mPlayer;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
-        requestWindowFeature(Window.FEATURE_NO_TITLE);
+        requestWindowFeature(Window.FEATURE_NO_TITLE);  //界面显示无标题
 
         final Window win = getWindow();
         win.addFlags(WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED);
 
-        if (!isScreenOn()) {
+        if (!isScreenOn()) {      //锁屏后到了提示时间点亮屏幕，
-            win.addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON
+            win.addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON //保持屏幕亮着
-                    | WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON
+                    | WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON    //点亮屏幕
-                    | WindowManager.LayoutParams.FLAG_ALLOW_LOCK_WHILE_SCREEN_ON
+                    | WindowManager.LayoutParams.FLAG_ALLOW_LOCK_WHILE_SCREEN_ON    //允许点亮时锁屏
                     | WindowManager.LayoutParams.FLAG_LAYOUT_INSET_DECOR);
         }
 
         Intent intent = getIntent();
 
         try {
-            mNoteId = Long.valueOf(intent.getData().getPathSegments().get(1));
+            mNoteId = Long.valueOf(intent.getData().getPathSegments().get(1));//获取ID
-            mSnippet = DataUtils.getSnippetById(this.getContentResolver(), mNoteId);
+            mSnippet = DataUtils.getSnippetById(this.getContentResolver(), mNoteId);//根据ID获取标签的内容，利用getContentResolver()可以得到当前应用的实例
+
+            /*判断标签是否达到符合的长度*/
             mSnippet = mSnippet.length() > SNIPPET_PREW_MAX_LEN ? mSnippet.substring(0,
                     SNIPPET_PREW_MAX_LEN) + getResources().getString(R.string.notelist_string_info)
                     : mSnippet;
-        } catch (IllegalArgumentException e) {
+        } catch (IllegalArgumentException e) { //处理异常，显示异常信息
             e.printStackTrace();
             return;
         }
 
         mPlayer = new MediaPlayer();
         if (DataUtils.visibleInNoteDatabase(getContentResolver(), mNoteId, Notes.TYPE_NOTE)) {
-            showActionDialog();
+            showActionDialog(); //弹出对话框
-            playAlarmSound();
+            playAlarmSound();   //响起提示音
         } else {
-            finish();
+            finish();   //完成闹钟
         }
     }
 
-    private boolean isScreenOn() {
+    private boolean isScreenOn() {  //判断是否锁屏
         PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
         return pm.isScreenOn();
     }
 
-    private void playAlarmSound() {
+    private void playAlarmSound() { //响起提示音
-        Uri url = RingtoneManager.getActualDefaultRingtoneUri(this, RingtoneManager.TYPE_ALARM);
+        Uri url = RingtoneManager.getActualDefaultRingtoneUri(this, RingtoneManager.TYPE_ALARM);    //获取系统默认铃声
 
-        int silentModeStreams = Settings.System.getInt(getContentResolver(),
+        int silentModeStreams = Settings.System.getInt(getContentResolver(),    //通过settings这个类来获取数据库中的数据
                 Settings.System.MODE_RINGER_STREAMS_AFFECTED, 0);
 
         if ((silentModeStreams & (1 << AudioManager.STREAM_ALARM)) != 0) {
@@ -100,20 +102,20 @@ public class AlarmAlertActivity extends Activity implements OnClickListener, OnD
             mPlayer.setAudioStreamType(AudioManager.STREAM_ALARM);
         }
         try {
-            mPlayer.setDataSource(this, url);
+            mPlayer.setDataSource(this, url);   //设置数据来源url
-            mPlayer.prepare();
+            mPlayer.prepare();  //准备同步
-            mPlayer.setLooping(true);
+            mPlayer.setLooping(true);   //设置循环播放
-            mPlayer.start();
+            mPlayer.start();    //开始播放
-        } catch (IllegalArgumentException e) {
+        } catch (IllegalArgumentException e) { //传递了一个不合法或不正确的参数时出现异常
             // TODO Auto-generated catch block
             e.printStackTrace();
-        } catch (SecurityException e) {
+        } catch (SecurityException e) { //程序使用不当存在某些危险的操作引发安全问题
             // TODO Auto-generated catch block
             e.printStackTrace();
-        } catch (IllegalStateException e) {
+        } catch (IllegalStateException e) { //在不合理或不正确时间内唤醒一方法时出现异常
             // TODO Auto-generated catch block
             e.printStackTrace();
-        } catch (IOException e) {
+        } catch (IOException e) { //文件读取异常
             // TODO Auto-generated catch block
             e.printStackTrace();
         }
@@ -121,37 +123,39 @@ public class AlarmAlertActivity extends Activity implements OnClickListener, OnD
 
     private void showActionDialog() {
         AlertDialog.Builder dialog = new AlertDialog.Builder(this);
-        dialog.setTitle(R.string.app_name);
+        dialog.setTitle(R.string.app_name); //对话框设置标题
-        dialog.setMessage(mSnippet);
+        dialog.setMessage(mSnippet);    //对话框设置内容
-        dialog.setPositiveButton(R.string.notealert_ok, this);
+        dialog.setPositiveButton(R.string.notealert_ok, this);  //设置确定按钮
         if (isScreenOn()) {
-            dialog.setNegativeButton(R.string.notealert_enter, this);
+            dialog.setNegativeButton(R.string.notealert_enter, this); //设置取消按钮
         }
         dialog.show().setOnDismissListener(this);
     }
 
     public void onClick(DialogInterface dialog, int which) {
-        switch (which) {
+        switch (which) {    //选择下一步的操作
-            case DialogInterface.BUTTON_NEGATIVE:
+            case DialogInterface.BUTTON_NEGATIVE:   //取消
-                Intent intent = new Intent(this, NoteEditActivity.class);
+                /*实现两个类的跳转*/
-                intent.setAction(Intent.ACTION_VIEW);
+                Intent intent = new Intent(this, NoteEditActivity.class);   //创建intent对象
-                intent.putExtra(Intent.EXTRA_UID, mNoteId);
+                intent.setAction(Intent.ACTION_VIEW);   //调用隐式intent调用
-                startActivity(intent);
+                intent.putExtra(Intent.EXTRA_UID, mNoteId); //Intent.EXTRA_UID为键名，mNoteId为键对应的值，把想要传递的数据暂存在intent中，当另一个活动启动后，再把这些数据从intent缓存中取出
+                startActivity(intent);  //开始跳转
                 break;
+
             default:
-                break;
+                break;  //确定
         }
     }
 
     public void onDismiss(DialogInterface dialog) {
-        stopAlarmSound();
+        stopAlarmSound();   //停止闹钟声音
-        finish();
+        finish();   //完成动作
     }
 
     private void stopAlarmSound() {
         if (mPlayer != null) {
-            mPlayer.stop();
+            mPlayer.stop(); //停止播放
-            mPlayer.release();
+            mPlayer.release();  //释放对象
             mPlayer = null;
         }
     }