我正在尝试创建一个显示有关用户从日期选择器和时间选择器输入的所选时间和日期的通知的应用程序，但是在选择了时间和日期之后，该应用程序未在该确切时间显示。相反，当我按“确定”按钮几秒钟后就会触发。 以下是主要活动的代码：
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.add_reminder);
Reminder_Title=(EditText)findViewById(R.id.Reminder_Title);
tDate=(TextView) findViewById(R.id.Date_text);
tTime=(TextView)findViewById(R.id.Time_text);
tRepeat=(TextView)findViewById(R.id.Repeat_text);
doneFab=(FloatingActionButton)findViewById(R.id.donefab);
calendar=Calendar.getInstance();
int Hour = calendar.get(Calendar.HOUR_OF_DAY);
int Mint = calendar.get(Calendar.MINUTE);
final int Year = calendar.get(Calendar.YEAR);
final int Month = calendar.get(Calendar.MONTH) + 1;
final int Day = calendar.get(Calendar.DAY_OF_MONTH);
mDate = Day + "/" + Month + "/" + Year;
tDate.setText(mDate);
if(Mint<10) {
mTime=Hour + ":"+0+ Mint;
}
else
{
mTime=Hour + ":" + Mint;
}
tTime.setText(mTime);
doneFab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (Reminder_Title.getText().toString().length() != 0) {
AlertDialog.Builder Message = new AlertDialog.Builder(Add_Reminder.this);
Message.setTitle("Message");
Message.setMessage("Reminder Added!!");
Message.setNegativeButton("Ok", new DialogInterface.OnClickListener() {
@RequiresApi(api = Build.VERSION_CODES.M)
@Override
public void onClick(DialogInterface dialog, int which) {
// Set calender for notifcation
calendar.set(Calendar.MONTH, --nMonth);
calendar.set(Calendar.YEAR, nYear);
calendar.set(Calendar.DAY_OF_MONTH, nDay);
calendar.set(Calendar.HOUR_OF_DAY, nHour);
calendar.set(Calendar.MINUTE, nMinute);
calendar.set(Calendar.SECOND, 0);
calendar.set(Calendar.MILLISECOND, 0);
long selectedTimestamp = calendar.getTimeInMillis();
Intent intent=new Intent(Add_Reminder.this,AlarmSetter.class);
PendingIntent p1=PendingIntent.getBroadcast(getApplicationContext(),0, intent,0);
AlarmManager a=(AlarmManager)getSystemService(ALARM_SERVICE);
a.setExactAndAllowWhileIdle(AlarmManager.RTC,selectedTimestamp,p1);
}
});
AlertDialog alert = Message.create();
alert.show();
}
}
});
}
public void setDate(View view) {
Calendar c=Calendar.getInstance();
int mYear = c.get(Calendar.YEAR);
int mMonth = c.get(Calendar.MONTH);
int mDay = c.get(Calendar.DAY_OF_MONTH);
DatePickerDialog datePickerDialog = new DatePickerDialog(this, new DatePickerDialog.OnDateSetListener()
{
@Override
public void onDateSet(DatePicker view, int year, int monthOfYear, int dayOfMonth)
{
//getting reminder set dates and day
nYear=year;
nMonth=monthOfYear;
nDay=dayOfMonth;
mDate=dayOfMonth + "-" + (monthOfYear + 1) + "-" + year;
tDate.setText(mDate);
}
}, mYear, mMonth, mDay);
datePickerDialog.show();
}
public void setTime(View view) {
Calendar c = Calendar.getInstance();
int mHour = c.get(Calendar.HOUR);
int mMinute = c.get(Calendar.MINUTE);
// Launch Time Picker Dialog
TimePickerDialog timePickerDialog = new TimePickerDialog(this,
new TimePickerDialog.OnTimeSetListener() {
@Override
public void onTimeSet(TimePicker view, int HOUR_OF_DAY,
int minute) {
nHour=HOUR_OF_DAY;
nMinute=minute;
if(minute<10) {
mTime=HOUR_OF_DAY + ":"+0+ minute;
}
else
{
mTime=HOUR_OF_DAY + ":" + minute;
}
tTime.setText(mTime);
}
}, mHour, mMinute, false);
timePickerDialog.show();
}
public void setRepeating(View view)
{
final String[] items = new String[6];
items[0] = "No Repeating";
items[1] = "Every Hour";
items[2] = "Every Day";
items[3] = "Every Week";
items[4] = "Every Month";
items[5] = "Every Year";
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle("Select Type");
builder.setItems(items, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int item) {
String mRepeatType = items[item];
tRepeat.setText(mRepeatType);
}
});
AlertDialog alert = builder.create();
alert.show();
}
Alarm.java代码
public class AlarmSetter extends BroadcastReceiver{
@Override public void onReceive(Context context, Intent intent) {
String id="main_channel";
if(Build.VERSION.SDK_INT>=Build.VERSION_CODES.O) {
Toast.makeText(context, "Wake up", Toast.LENGTH_LONG).show();
NotificationManager notificationManager=(NotificationManager)context.getSystemService(Context.NOTIFICATION_SERVICE);
CharSequence name="Channel Name";
String description="Channel Description";
int importance=NotificationManager.IMPORTANCE_HIGH;
NotificationChannel notificationChannel=new NotificationChannel(id,name,importance);
notificationChannel.setDescription(description);
notificationChannel.enableLights(true);
notificationChannel.setLightColor(Color.WHITE);
notificationChannel.enableVibration(false);
if(notificationManager!=null)
{
notificationManager.createNotificationChannel(notificationChannel);
}
NotificationCompat.Builder notificationBuilder =new NotificationCompat.Builder(context,id);
notificationBuilder.setSmallIcon(R.drawable.timesmall);
notificationBuilder.setContentTitle("Notification Title");
notificationBuilder.setLights(Color.WHITE,500,5000);
notificationBuilder.setColor(Color.RED);
notificationBuilder.setDefaults(Notification.DEFAULT_SOUND);
NotificationManagerCompat notificationManagerCompat=NotificationManagerCompat.from(context);
notificationManagerCompat.notify(1000,notificationBuilder.build());
}
}
}
答案 0 :(得分：0)
这有点远，但是我认为您的错误是calendar.set(Calendar.MONTH, --nMonth);
删除pre-decrement statement --，它应该可以工作。
--nMonth意味着执行nMonth = nMonth - 1，然后在语句nMonth中使用新的calendar.set(Calendar.MONTH, nMonth); <-这里nMonth比以前少一个。这意味着您每次设置闹钟都会在一个月前设置。
也请查看google-java样式指南http://google.github.io/styleguide/javaguide.html#s5.2.7-local-variable-names，它告诉您如何编写更具可读性的代码。特别是Month，Hour，Mint ...应该全部小写。