新手项目 - 从 BroadcastReceive 开始一个活动

Question

I'm trying to build a simple daily reminder app as my first Android project and I'm just stucked now. Too much information from hours watching tutorials. :)

So I would like some help to understand the code behind my idea so hopefully someone explains this with ease :)

• Three times a day I want an alarm/reminder/splash to set off for ten seconds with different pictures and sounds depending on the alarmtime. An ability to tap/swipe to stop it before 10 seconds.

alarm1 ---alarm1time08:10 ---alarm1pic1.jpg ---alarm1Sound1.mp3

alarm2 ---alarm2time12:30 ---alarm2pic1.jpg ---alarm2Sound1.mp3

alarm3 ---alarm3time18:45 ---alarm3pic1.jpg ---alarm3Sound1.mp3

So how do I do this?

I'm using Android Studio 2.3 (to slow computer for 3.x...), Java and my phones are Lollipop 5.1 API level 22 and Marshmallow 6.0 API level 23

This is my code that actually works without error..

But now i don't know how open an activity with my image and sounds. I got a RED startActivity when I tried it in hRec.

MainActivity.java

 package com.hlm.myreminder; import android.app.AlarmManager; import android.app.PendingIntent; import android.content.Intent; import android.os.Bundle; import android.support.v7.app.AppCompatActivity; import android.util.Log; import java.util.Calendar; public class MainActivity extends AppCompatActivity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); int hHour1 = 08; int hMin1 = 10; Calendar hCal1 = Calendar.getInstance(); hCal1.set(Calendar.HOUR_OF_DAY, hHour1); hCal1.set(Calendar.MINUTE, hMin1); hCal1.set(Calendar.SECOND, 0); Log.v("hLogging","cal set"); Intent hIntent = new Intent(getApplication(),hRec.class); PendingIntent hPi = PendingIntent.getBroadcast(getApplicationContext(),0,hIntent,PendingIntent.FLAG_UPDATE_CURRENT); Log.v("hLogging","intent set"); AlarmManager hAlMgr = (AlarmManager)getSystemService(ALARM_SERVICE); hAlMgr.setRepeating(AlarmManager.RTC_WAKEUP,hCal1.getTimeInMillis(),hAlMgr.INTERVAL_DAY,hPi); Log.v("hLogging","am set"); // startActivity(new Intent(this, hshowreminderpic1.class)); //works // Log.v("hLogging","goto hshowreminderpic1 done"); //works } }

hRec.java

 package com.hlm.myreminder; import android.content.BroadcastReceiver; import android.content.Context; import android.content.Intent; import android.util.Log; public class hRec extends BroadcastReceiver { @Override public void onReceive(Context context, Intent hIntent) { Log.d("hLogging", "hRec:BroadcastReceiverAlarm"); // show hshowreminderpic1 /* startActivity gets RED */ // startActivity(new Intent(this, hshowreminderpic1.class)); // Log.v("hLogging","goto hshowreminderpic1 request"); }

AndroidManifest.xml

 <?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.hlm.myreminder"> <uses-permission android:name="android.permission.WAKE_LOCK" /> <uses-permission android:name="com.android.alarm.permission.SET_ALARM"/> <application android:allowBackup="true" android:icon="@drawable/h_icon72" android:label="@string/app_name" android:supportsRtl="true" android:theme="@style/AppTheme"> <activity android:name=".MainActivity"> <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> <activity android:name=".hshowreminderpic1"/> <receiver android:name=".hRec"></receiver> </application> </manifest>

Answer 1

You need to pass context to start your activity from hRec.java as hRec is not an activity. So simply write

Intent i = new Intent(context, hshowreminderpic1.class); 
i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK); 
context.startActivity(i);

Answer 2

尝试使用这个：

context.startActivity(new Intent(this, hshowreminderpic1.class));