Intent调用时出现NullPointerException

Question

package com.exercise.AndroidAlarmService;

import java.util.Calendar;

import android.app.Activity;
import android.app.AlarmManager;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.util.DisplayMetrics;
import android.util.Log;
import android.view.Window;
import android.view.WindowManager;
import android.widget.LinearLayout;
import android.widget.TextView;

public class AlarmDialogActivity extends Activity {

static Context who;
static int screenWidth;
static int screenHeight;
static Thread tr;

private DrawView dr;

public Handler updateHandler = new Handler() {
    /** Gets called on every message that is received */
    // @Override
    public void handleMessage(Message msg) {
        if (dr != null) {
            Log.w("where", "Update called");
            dr.invalidate();
        }
        super.handleMessage(msg);
    }
};

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    requestWindowFeature(Window.FEATURE_NO_TITLE);
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
            WindowManager.LayoutParams.FLAG_FULLSCREEN);
    DisplayMetrics metrics = getResources().getDisplayMetrics();
    screenWidth = metrics.widthPixels;
    screenHeight = metrics.heightPixels;
    Log.w("haha", "haha " + screenWidth + " " + screenWidth * 0.2 + " "
            + screenWidth * 0.4 + " " + screenWidth * 0.6 + " "
            + screenWidth * 0.8 + " " + screenWidth);
    dr = new DrawView(this);
    setContentView(dr);

    who = this;
    final TextView tym = (TextView) findViewById(R.id.idalarmtime);
    final LinearLayout ll = (LinearLayout) this.findViewById(R.id.layc);
    tr = new Thread(new UpdateThread());
    tr.start();
}

public class UpdateThread implements Runnable {

    @Override
    public void run() {
        while (true) {
            AlarmDialogActivity.this.updateHandler.sendEmptyMessage(0);
        }
    }

}

public void snooze() {

    if (AlarmDialogActivity.this == null) {
        Log.w("where", "its null");
    } else {
        Log.w("where", "its not null");
    }

    if (MyAlarmService.class == null) {
        Log.w("where", "its null");
    } else {
        Log.w("where", "its not null");
    }

    Intent myIntent = new Intent(AlarmDialogActivity.this,
            MyAlarmService.class);
    myIntent.putExtra("id", "0");
    myIntent.putExtra("tym", "21:55");
    PendingIntent pendingIntent = PendingIntent.getService(
            AlarmDialogActivity.this, 0, myIntent, 0);
    AlarmManager alarmManager = (AlarmManager) getSystemService(ALARM_SERVICE);
    Calendar calendar = Calendar.getInstance();
    calendar.setTimeInMillis(System.currentTimeMillis());
    calendar.clear();
    calendar.set(2013, 4, 21, 18, 6);
    alarmManager.set(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(),
            pendingIntent);

    Log.w("where", "snooze time set");
    this.finish();
}

}

这是意图服务

package com.exercise.AndroidAlarmService;

import android.app.IntentService;
import android.app.Service;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;

public class MyAlarmService extends IntentService {

public MyAlarmService() {
    super("MyAlarmService");
    // TODO Auto-generated constructor stub
    Log.w("where", "intent Created");
}

@Override
protected void onHandleIntent(Intent intent) {
    Log.w("Where", "Gone Off");
    String id = intent.getExtras().getString("id");
    Log.w("Where", "" + id);
    String tym = intent.getExtras().getString("tym");
    Log.w("Where", "" + tym);

    Service myService;
    myService = this;
    Intent dialogIntent = new Intent(myService, AlarmDialogActivity.class);
    Bundle b = new Bundle();
    b.putString("tym","21:50");
    dialogIntent.putExtras(b);
    dialogIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    myService.startActivity(dialogIntent);

}
}

在点击按钮时调用snooze（）...但是我在创建IntentService时在snooze（）中获得了nullpointerexcpetion

05-21 18:30:39.625: E/AndroidRuntime(11580): FATAL EXCEPTION: main
05-21 18:30:39.625: E/AndroidRuntime(11580): java.lang.NullPointerException
05-21 18:30:39.625: E/AndroidRuntime(11580):    at             android.content.ContextWrapper.getPackageName(ContextWrapper.java:120)
05-21 18:30:39.625: E/AndroidRuntime(11580):    at android.content.ComponentName.<init>(ComponentName.java:75)
05-21 18:30:39.625: E/AndroidRuntime(11580):    at android.content.Intent.<init>(Intent.java:2823)
05-21 18:30:39.625: E/AndroidRuntime(11580):    at com.exercise.AndroidAlarmService.AlarmDialogActivity.snooze(AlarmDialogActivity.java:88)
05-21 18:30:39.625: E/AndroidRuntime(11580):    at com.exercise.AndroidAlarmService.DrawView.onTouchEvent(DrawView.java:186)
05-21 18:30:39.625: E/AndroidRuntime(11580):    at android.view.View.dispatchTouchEvent(View.java:3885)
05-21 18:30:39.625: E/AndroidRuntime(11580):    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:942)
05-21 18:30:39.625: E/AndroidRuntime(11580):    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:942)
05-21 18:30:39.625: E/AndroidRuntime(11580):    at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:1769)
05-21 18:30:39.625: E/AndroidRuntime(11580):    at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1135)
05-21 18:30:39.625: E/AndroidRuntime(11580):    at android.app.Activity.dispatchTouchEvent(Activity.java:2096)
05-21 18:30:39.625: E/AndroidRuntime(11580):    at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:1753)
05-21 18:30:39.625: E/AndroidRuntime(11580):    at android.view.ViewRoot.deliverPointerEvent(ViewRoot.java:2227)
05-21 18:30:39.625: E/AndroidRuntime(11580):    at android.view.ViewRoot.handleMessage(ViewRoot.java:1886)
05-21 18:30:39.625: E/AndroidRuntime(11580):    at android.os.Handler.dispatchMessage(Handler.java:99)
05-21 18:30:39.625: E/AndroidRuntime(11580):    at android.os.Looper.loop(Looper.java:130)
05-21 18:30:39.625: E/AndroidRuntime(11580):    at android.app.ActivityThread.main(ActivityThread.java:3687)
05-21 18:30:39.625: E/AndroidRuntime(11580):    at java.lang.reflect.Method.invokeNative(Native Method)
05-21 18:30:39.625: E/AndroidRuntime(11580):    at java.lang.reflect.Method.invoke(Method.java:507)
05-21 18:30:39.625: E/AndroidRuntime(11580):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:867)
05-21 18:30:39.625: E/AndroidRuntime(11580):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:625)
05-21 18:30:39.625: E/AndroidRuntime(11580):    at dalvik.system.NativeStart.main(Native Method)