从PendingIntent.getActivity获取空指针异常Android

Question

我想添加一个从onClick按钮实现警报，但我得到一个空指针异常“android：app.PendingIntent.getActivity（PendingIntent.java ：257）“and”at android：app.PendingIntent.getActivity（PendingIntent.java:224）“。

这里是我的代码，点击“添加”按钮应该创建Pending Intent。

public class DisplayAlertMessage extends Activity { 
private int mYear, mMonth, mDay, mHour, mMinute; 
private long alarm_time; 
    private int rem = 0; 
    private String date,time; 
    private String lists1[] = new String[10]; 
static final int DATE_DIALOG_ID = 999; 

@SuppressLint("InflateParams") 
public void displayAlertDialog(LayoutInflater inflater,final MainActivity obj,final MainActivity obj1,final Context con) { 
    /** This intent invokes the activity DemoActivity, which in turn opens the AlertDialog window */ 
    final Intent in = new Intent("com.example.todotry_1.demoactivity"); 
    final View alertLayout = inflater.inflate(R.layout.layout_custom_dialog, null); 
    final EditText Note = (EditText) alertLayout.findViewById(R.id.Note); 
    final EditText Lists = (EditText) alertLayout.findViewById(R.id.Lists); 
    final TextView Remind = (TextView) alertLayout.findViewById(R.id.Remind); 
    final TextView Time = (TextView) alertLayout.findViewById(R.id.Time); 
    final TextView Date = (TextView) alertLayout.findViewById(R.id.Date); 
    final TextView Timeval = (TextView) alertLayout.findViewById(R.id.Timeval); 
    final TextView Dateval = (TextView) alertLayout.findViewById(R.id.Dateval); 
    final ImageView iv=(ImageView) alertLayout.findViewById(R.id.img); 
    i=iv; 
    AlertDialog.Builder alert = new AlertDialog.Builder(obj,R.style.DialogTheme); 
    Remind.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View v) { 
       Log.d("onCLICK","REMIND"); 
       Toast.makeText(con, "REMIND CLICKED", Toast.LENGTH_SHORT).show(); 
       Remind.setVisibility(View.GONE); 
       Time.setVisibility(View.VISIBLE); 
       Date.setVisibility(View.VISIBLE); 
       rem = 1; 
       Time.setOnClickListener(new OnClickListener() { 
       @Override 
          public void onClick(View v) { 
          final Calendar c = Calendar.getInstance(); 
           mHour = c.get(Calendar.HOUR_OF_DAY); 
           mMinute = c.get(Calendar.MINUTE); 

           // Launch Time Picker Dialog 
           TimePickerDialog tpd = new TimePickerDialog(obj,new TimePickerDialog.OnTimeSetListener() 
           { 

              @Override 
              public void onTimeSet(TimePicker view, int hourOfDay,int minute) { 
              // Display Selected time in textbox 
              Timeval.setVisibility(View.VISIBLE); 
               Timeval.setText(hourOfDay + ":" + minute); 
              } 
             }, mHour, mMinute, false); 
            tpd.show(); 
            time = mHour+":"+mMinute; 
          } 
        }); 
       Date.setOnClickListener(new OnClickListener() { 
          @Override 
          public void onClick(View v) { 
          final Calendar c = Calendar.getInstance(); 
           mYear = c.get(Calendar.YEAR); 
           mMonth = c.get(Calendar.MONTH); 
           mDay = c.get(Calendar.DAY_OF_MONTH); 

          // Launch Date Picker Dialog 
          DatePickerDialog dpd = new DatePickerDialog(obj,new DatePickerDialog.OnDateSetListener() { 
       @Override 
             public void onDateSet(DatePicker view, int year, int monthOfYear, int dayOfMonth) { 
              // Display Selected date in textbox 
             Dateval.setVisibility(View.VISIBLE); 
              Dateval.setText(dayOfMonth + "-"+ (monthOfYear + 1) + "-" + year); 
       } 
            }, mYear, mMonth, mDay); 
           dpd.show(); 
           date = mDay+"-"+mMonth+"-"+mYear; 
          } 
        }); 
       GregorianCalendar calendar = new GregorianCalendar(mYear,mMonth,mDay, mHour, mMinute); 
       alarm_time = calendar.getTimeInMillis(); 
      } 
     }); 


    alert.setTitle("ADD NOTE"); 
    alert.setView(alertLayout); 
    alert.setCancelable(false); 
    alert.setNegativeButton("Cancel", new DialogInterface.OnClickListener() { 

    @Override 
    public void onClick(DialogInterface dialog, int which) { 
    Toast.makeText(con, "Cancel clicked", Toast.LENGTH_SHORT).show(); 
    } 
    }); 

    alert.setPositiveButton("ADD", new DialogInterface.OnClickListener() { 

    @Override 
    public void onClick(DialogInterface dialog, int which) { 
    // code for matching password 
    String note = Note.getText().toString(); 
    String lists = Lists.getText().toString() + '\n'; 

    int l=lists.length(); 
    int i=0; 
    String one=""; 
    char q; 
    String main1=""; 
    int count = 0,j=0; 
    for (i=0;i<l;i++) 
    { 
     q=lists.charAt(i); 
     if(q!='\n') 
      one += q; 
     else 
     { 
      Log.d("the string",":" + one); 
      //Toast.makeText(getBaseContext(), "Words " + one , Toast.LENGTH_SHORT).show(); 
      main1 += count + " : " + one; 
      lists1[j++] = one; 
      one=""; 
     } 
     count++; 
    } 
    Log.d("DISplay","111before finish add"); 
    if((date == null)^(time == null)) 
    { 
     Toast.makeText(con, "Enter both date and time to set alarm", Toast.LENGTH_SHORT).show(); 
    } 
    else{ 
    TaskDBHelper ob = new TaskDBHelper(obj1); 
    SQLiteDatabase sqlDB = ob.getWritableDatabase(); 
    if((date != null)&(time != null)) 
    { 
     String f1 = String.format("INSERT INTO prioritised (task,date,time,ringtone,done,Hidden) VALUES('"+note+"','"+date+"','"+time+"','"+""+"',0,"+MainActivity.getStat()+")"); 
     sqlDB.execSQL(f1); 
     if((j!=0)&(main1!="\n")) 
     { 
      int id=0; 
      Cursor cursor = sqlDB.rawQuery("SELECT _id from prioritised where task = '"+note+"'",null); 

      if (cursor != null) { 
        try { 
         if (cursor.moveToFirst()) { 
          id = cursor.getInt(0); 
         } 
        } finally { 
         cursor.close(); 
        } 
       } 
      Log.d("Prio"," "+id); 
      String add; 
      for(int k=0;k<j;k++) 
      { 
       add = String.format("INSERT INTO sublistprioritised (_id1,sublist,done,hidden) VALUES("+id+",'"+lists1[k]+"',0,"+MainActivity.getStat()+")"); 
       sqlDB.execSQL(add); 
      } 

     } 

      /** Creating a Pending Intent */ 
      Context x=getBaseContext(); 
          int requestID = (int) System.currentTimeMillis(); 
      PendingIntent operation = PendingIntent.getActivity(x, requestID, in,Intent.FLAG_ACTIVITY_NEW_TASK); 

      /** Getting a reference to the System Service ALARM_SERVICE */ 
      AlarmManager alarmManager = (AlarmManager) x.getSystemService(ALARM_SERVICE); 

      /** Setting an alarm, which invokes the operation at alart_time */ 
        alarmManager.set(AlarmManager.RTC_WAKEUP , alarm_time , operation); 
        /** Alert is set successfully */ 
        Toast.makeText(x, "Alarm is set successfully",Toast.LENGTH_SHORT).show(); 
    } 
    else{ 
    String f2 = String.format("INSERT INTO unprioritised (task,done,Hidden) VALUES('"+note+"',0,"+MainActivity.getStat()+")"); 
    sqlDB.execSQL(f2); 
    if((j!=0)&(main1!="\n")) 
    { 
     int id=0; 
     Cursor cursor = sqlDB.rawQuery("SELECT _id from unprioritised where task = '"+note+"'",null); 
     if (cursor != null) { 
       try { 
        if (cursor.moveToFirst()) { 
         id = cursor.getInt(0); 
        } 
       } finally { 
        cursor.close(); 
       } 
      } 
     String add; 
     for(int k=0;k<j;k++) 
     { 
      add = String.format("INSERT INTO sublistunprioritised (_id1,sublist,done,Hidden) VALUES("+id+",'"+lists1[k]+"',0,"+MainActivity.getStat()+")"); 
      sqlDB.execSQL(add); 
     } 

    } 
    } 
    } 
    } 
    }); 
    AlertDialog dialog = alert.create(); 
    dialog.show(); 
    } 
} 

谢谢。任何帮助表示赞赏。

这里的logcat的

04-02 13:38:03.922: E/AndroidRuntime(2120): FATAL EXCEPTION: main 
04-02 13:38:03.922: E/AndroidRuntime(2120): Process: com.example.todotry_1, PID: 2120 
04-02 13:38:03.922: E/AndroidRuntime(2120): java.lang.NullPointerException 
04-02 13:38:03.922: E/AndroidRuntime(2120): at android.app.PendingIntent.getActivity(PendingIntent.java:257) 
04-02 13:38:03.922: E/AndroidRuntime(2120): at android.app.PendingIntent.getActivity(PendingIntent.java:224) 
04-02 13:38:03.922: E/AndroidRuntime(2120): at com.example.todotry_1.DisplayAlertMessage$4.onClick(DisplayAlertMessage.java:244) 
04-02 13:38:03.922: E/AndroidRuntime(2120): at com.android.internal.app.AlertController$ButtonHandler.handleMessage(AlertController.java:166) 
04-02 13:38:03.922: E/AndroidRuntime(2120): at android.os.Handler.dispatchMessage(Handler.java:102) 
04-02 13:38:03.922: E/AndroidRuntime(2120): at android.os.Looper.loop(Looper.java:136) 
04-02 13:38:03.922: E/AndroidRuntime(2120): at android.app.ActivityThread.main(ActivityThread.java:5017) 
04-02 13:38:03.922: E/AndroidRuntime(2120): at java.lang.reflect.Method.invokeNative(Native Method) 
04-02 13:38:03.922: E/AndroidRuntime(2120): at java.lang.reflect.Method.invoke(Method.java:515) 
04-02 13:38:03.922: E/AndroidRuntime(2120): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779) 
04-02 13:38:03.922: E/AndroidRuntime(2120): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595) 
04-02 13:38:03.922: E/AndroidRuntime(2120): at dalvik.system.NativeStart.main(Native Method) 

更新日志：

04-02 15:59:03.140: E/AndroidRuntime(1880): android.database.sqlite.SQLiteConstraintException: columns _id1, sublist are not unique (code 19) 
04-02 15:59:03.140: E/AndroidRuntime(1880): at android.database.sqlite.SQLiteConnection.nativeExecuteForChangedRowCount(Native Method) 
04-02 15:59:03.140: E/AndroidRuntime(1880): at android.database.sqlite.SQLiteConnection.executeForChangedRowCount(SQLiteConnection.java:734) 
04-02 15:59:03.140: E/AndroidRuntime(1880): at android.database.sqlite.SQLiteSession.executeForChangedRowCount(SQLiteSession.java:754) 
04-02 15:59:03.140: E/AndroidRuntime(1880): at android.database.sqlite.SQLiteStatement.executeUpdateDelete(SQLiteStatement.java:64) 
04-02 15:59:03.140: E/AndroidRuntime(1880): at android.database.sqlite.SQLiteDatabase.executeSql(SQLiteDatabase.java:1674) 
04-02 15:59:03.140: E/AndroidRuntime(1880): at android.database.sqlite.SQLiteDatabase.execSQL(SQLiteDatabase.java:1603) 
04-02 15:59:03.140: E/AndroidRuntime(1880): at com.example.todotry_1.DisplayAlertMessage$4.onClick(DisplayAlertMessage.java:236) 
04-02 15:59:03.140: E/AndroidRuntime(1880): at com.android.internal.app.AlertController$ButtonHandler.handleMessage(AlertController.java:166) 
04-02 15:59:03.140: E/AndroidRuntime(1880): at android.os.Handler.dispatchMessage(Handler.java:102) 
04-02 15:59:03.140: E/AndroidRuntime(1880): at android.os.Looper.loop(Looper.java:136) 
04-02 15:59:03.140: E/AndroidRuntime(1880): at android.app.ActivityThread.main(ActivityThread.java:5017) 
04-02 15:59:03.140: E/AndroidRuntime(1880): at java.lang.reflect.Method.invokeNative(Native Method) 
04-02 15:59:03.140: E/AndroidRuntime(1880): at java.lang.reflect.Method.invoke(Method.java:515) 
04-02 15:59:03.140: E/AndroidRuntime(1880): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779) 
04-02 15:59:03.140: E/AndroidRuntime(1880): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595) 
04-02 15:59:03.140: E/AndroidRuntime(1880): at dalvik.system.NativeStart.main(Native Method) 

Answer 1

它看起来是不必要的来电来访getBaseContext()，你可能不希望使用currentTimeMillis()作为requestCode，只是如果您需要取消PendingIntent：

/** Creating a Pending Intent */ 
      //Context x=getBaseContext(); 
      //int requestID = (int) System.currentTimeMillis(); 

      PendingIntent operation = null; 
      //Make sure nothing is null for debugging purposes 
      if (con == null){ 
       Log.e("onCLICK","con is null"); 
      } 
      else if (in == null){ 
       Log.e("onCLICK","in is null"); 
      } 
      else{ 
       operation = PendingIntent.getActivity(con, 0, in,PendingIntent.FLAG_UPDATE_CURRENT); 
      } 

      if (operation != null){ 
       /** Getting a reference to the System Service ALARM_SERVICE */ 
       AlarmManager alarmManager = (AlarmManager) con.getSystemService(ALARM_SERVICE); 

       /** Setting an alarm, which invokes the operation at alart_time */ 
       alarmManager.set(AlarmManager.RTC_WAKEUP , alarm_time , operation); 
       /** Alert is set successfully */ 
       Toast.makeText(con, "Alarm is set successfully",Toast.LENGTH_SHORT).show(); 

      } 

看看这篇文章，以及为例子：PendingIntent works correctly for the first notification but incorrectly for the rest

编辑：我只是把的PendingIntent代码为AndroidStudio，它给了我这个消息：

必须有一个或多个：的PendingIntent。 FLAG_ONE_SHOT， PendingIntent.FLAG_NO_CREATE，PendingIntent.FLAG_CANCEL_CURRENT， PendingIntent.FLAG_UPDATE_CURRENT，Intent.FILL_IN_ACTION， Intent.FILL_IN_DATA，Intent.FILL_IN_CATEGORIES， Intent.FILL_IN_COMPONENT，Intent.FILL_IN_PACKAGE， Intent.FILL_IN_SOURCE_BOUNDS，Intent.FILL_IN_SELECTOR， Intent.FILL_IN_CLIP_DATA less ...（Ctrl + F1）报告两种类型的 问题：提供错误类型的资源标识符。对于 的例子，当调用Resources.getString（int id）时，你应该是 传递R.string.something，而不是R.drawable.something。将 错误的常量传递给需要一组特定的 常量之一的方法。例如，当调用View＃setLayoutDirection时， 参数必须是android.view.View.LAYOUT_DIRECTION_LTR或 android.view.View.LAYOUT_DIRECTION_RTL。

看看The Documentation欲了解更多信息，请点击这里使用有效标志。