Android的设置报警 - 提醒应用 [英] set Android alarm - Reminder app
问题描述
我按照<一href=\"http://www.techrepublic.com/blog/software-engineer/use-androids-alarmmanager-to-schedule-an-event/\"相对=nofollow>这个例子来设置报警。
这是在 MainActivity 类Droidgap扩展
This is the MainActivity class extends with Droidgap
@SuppressLint({ "JavascriptInterface", "SetJavaScriptEnabled" }) public class MainActivity extends DroidGap {
//CordovaWebView cwv;
final static public long ONE_SECOND = 1000;
final static public long TWENTY_SECONDS = ONE_SECOND * 20;
public PendingIntent pi;
public BroadcastReceiver br;
public AlarmManager am;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
WebView webView =new WebView(this);
//enabling javascript call to native code
webView.getSettings().setJavaScriptEnabled(true);
webView.setClickable(true);
//Give name to interface class, "Reminder" will call through javascript
webView.addJavascriptInterface(new MainActivity(), "Reminder");
webView.loadUrl("file:///android_asset/www/index.html");
setContentView(webView);
}
这做工精细,其设定报警及消防得当,
This work fine, its set alarm and fire properly,
@Override
public void onStart(){
super.onStart();
setup();
am.set( AlarmManager.ELAPSED_REALTIME_WAKEUP, SystemClock.elapsedRealtime() +
TWENTY_SECONDS, pi ); //This code works
}
虽然我尝试调用另一个方法有通过JavaScript其给予同样的NullPointerException code,这是我的JavascriptInterface,
While i try to invoke another method have same code through javascript its give NullPointerException, This is my JavascriptInterface,
@JavascriptInterface
public void showToast(String mssg) {
Log.v("AlrmMNG", am.toString());//Even this log is not working
am.set( AlarmManager.ELAPSED_REALTIME_WAKEUP, SystemClock.elapsedRealtime() +
TWENTY_SECONDS, pi );
Log.v("Alarm end", "Alarm set");
}
这是在 logcat的
03-05 12:25:58.330: E/AndroidRuntime(3444): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
03-05 12:55:59.710: W/System.err(3640): java.lang.NullPointerException
03-05 12:55:59.710: W/System.err(3640): at com.agrando.reminder_level1.MainActivity.showToast(MainActivity.java:67)
03-05 12:55:59.710: W/System.err(3640): at com.android.org.chromium.base.SystemMessageHandler.nativeDoRunLoopOnce(Native Method)
03-05 12:55:59.720: W/System.err(3640): at com.android.org.chromium.base.SystemMessageHandler.handleMessage(SystemMessageHandler.java:27)
03-05 12:55:59.730: W/System.err(3640): at android.os.Handler.dispatchMessage(Handler.java:102)
03-05 12:55:59.730: W/System.err(3640): at android.os.Looper.loop(Looper.java:136)
03-05 12:55:59.730: W/System.err(3640): at android.os.HandlerThread.run(HandlerThread.java:61)
03-05 12:55:59.830: I/chromium(3640): [INFO:CONSOLE(25)] "Uncaught Error: Error calling method on NPObject.", source: file:///android_asset/www/index.html (25)
我在几个不同的方法,但同样的结果尝试这一点。(我没有在这里添加设置()code,你可以从上面的链接中找到它。)请帮助**结果
* 这里是链接到项目文件一> * 的**
I tried this in several different methods but same result.( I didn't add setup() code in here, you can find it from link given above.) Please help **
*Here is the link to project files ***
推荐答案
上午
实例 AlarmManager
是空
你忘记使用前初始化之前,这样做的:
am
instance of AlarmManager
is null
before you forget to initialize it before using so do it as:
am=(AlarmManager)MainActivity.this.getSystemService(Context.ALARM_SERVICE);
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