C# - Alarm clock - Are two times the same - c#

I am in the process of making an alarm clock app in C# via Windows Forms. So far, I have this non-working section of code for my time checker.
string alarm = this.dateTimePicker1.Text;
if (DateTime.Now.ToString() == alarm)
{
MessageBox.Show("Alarm");
}
The DateTimePicker is configured for hours, minutes, and seconds. The above code is not displaying the message box at all. Where is the problem in the snippet?
Also: are there any more efficient ways of making an alarm clock

Try this to get you going:
Need to compare Hour and minutes.
private void CheckTime()
{
clock.Text = DateTime.Now.ToString("hh:mm:ss");
date.Text = DateTime.Now.ToLongDateString();
DateTime alarm = this.dateTimePicker1.Value;
DateTime currentTime = DateTime.Now;
if (alarm.Hour == currentTime.Hour && alarm.Minute == currentTime.Minute)
{
timer1.Enabled = false;
MessageBox.Show("Alarm");
}
}

Since it is an alarm clock, you'll want to do the compare including the time. That said, compare the .Ticks values of your DateTime objects:
if(DateTime.Now.Ticks >= this.DateTimePicker1.Value.Ticks)
{
// Sound the alarm
}
Depending on how the DateTimePicker you are using works, you may need to check the Value for null before comparing.

Modify the below code as needed. I find comparing strings to be a poor way to go about this.
DateTime alarm = this.dateTimePicker1.Value.Date;
if (DateTime.Compare(DateTime.Now.Date, alarm) == 0) {
MessageBow.Show("Alarm"); }

Problem is that you are looking for the exact match. Instead you should be looking if the alarm time has passed (so ">="). Also, the string comparison is not going to work for date time. You need to compare date/times:
string alarm = this.dateTimePicker1.Value;
if (DateTime.Now() >= alarm)
{
MessageBox.Show("Alarm");
}

Related

Compare DateTime against current system time?

I'm trying to make a C# method to fulfill this user story.
These are the 2 acceptance criteria
Start time must be at least one hour later than the current system time.
End time must be at last one hour after start time.
Both of the start and end time must be DateTime values, so I can parse it with the TryParse method.
Here's what I have in my code so far:
`
private DateTime datetime;
public DateTime datetimeStart { get; set; }
public DateTime datetimeEnd { get; set; }
while (true) {
Util.GetInput("Delivery window start (dd/mm/yyyy hh:mm)");
string userInput = ReadLine();
if(DateTime.TryParse(userInput, out datetime))
{
if (datetime.TimeOfDay.Hours - DateTime.Now.TimeOfDay.Hours >= 1) {
datetimeStart = datetime;
}
break;
}
else
{
WriteLine("\tDelivery window start must be at least one hour in the future.");
}
}
while (true) {
Util.GetInput("Delivery window end (dd/mm/yyyy hh:mm)");
string userInput = ReadLine();
if(DateTime.TryParse(userInput, out datetime))
{
if (datetime.TimeOfDay.Hours - datetimeStart.TimeOfDay.Hours >= 1) {
datetimeEnd = datetime;
}
break;
}
else
{
WriteLine("\tDelivery window end must be at least one hour later than the start.");
}
}
`
I'm not fully sure how the DateTime type works yet, but later on, I'd need to get an output string with this format:
"The pickup window for your order will be 04:00 on 30/10/2022 and 20:00 on 30/10/2022", and just replace the data in the string with values from datetimeStart and datetimeEnd
DateTime provides all the tools to write your conditions in straightforward code:
one hour later than / after checkTime
is just
checkTime.AddHours(1)
and
someTime must be at least one hour later than / after checkTime
becomes
someTime >= checkTime.AddHours(1)
So your code may look something like this:
...........................
if (datetime >= DateTime.Now.AddHours(1)) {
datetimeStart = datetime;
}
...........................
if (datetime >= datetimeStart.AddHours(1)) {
datetimeEnd = datetime;
}
...........................
A general rule of thumb is that any internal time keeping should be done in UTC, but when presenting in a UI (form or console) that you may show in local time.
Another rule is that when comparing DateTime objects that they should have the same Kind.
Perhaps add something like:
DateTime earliestStartTime = DateTime.UtcNow.AddHours(1);
Later if you have a variable named startTime you want to make sure that it is greater than or equal to earliestStartTime. Once you have startTime set, you can then have:
DateTime earliestEndTime = startTime.AddHours(1);
and likewise compare endTime to earliestStartTime for validity.
When presenting times to the user, you can use the .ToLocalTime() method.

Timespan Compare

I have following time samples:
06:09
08:10
23:12
00:06 // next day
00:52
I have a sample 00:31 (nextday) that needs to be compared and check if its less then the above samples.
if (cdnTime > nextNode)
{
//dosomething
}
cdnTime here is the 00:31 and nextNode is the above given multiple samples. Time 00:31 is greater then all samples except 00:52 so I need the if statement to be false until it reaches 00:52. How do I achieve this. Keeping in mind the time samples switch to next day, do I need to make it as DateTime and then compare or is there any way of comparison with TimeSpan without dates.
Yes you need to somehow tell that it's another day. You can either use a DateTime, but you could also initialize a timespan with an additional day - it provides a Parse-method for this:
using System;
using System.Globalization;
public class Program
{
public static void Main()
{
var cdnTime = TimeSpan.Parse("23:12", CultureInfo.InvariantCulture);
var nextTime = TimeSpan.Parse("01.00:03", CultureInfo.InvariantCulture);
Console.WriteLine(cdnTime.TotalMinutes);
Console.WriteLine(nextTime.TotalMinutes);
Console.WriteLine(cdnTime.CompareTo(nextTime));
Console.WriteLine(cdnTime < nextTime);
}
}
Another option would be to add the day afterwards:
var anotherTime = TimeSpan.FromMinutes(3);
anotherTime = anotherTime.Add(TimeSpan.FromDays(1));
Console.WriteLine(anotherTime.TotalMinutes);
You can try it out here:
https://dotnetfiddle.net/k39TIe

Calculate the difference between two dates and times

I'm having problem in calculating the difference between two days using form in Visual Studio c#. I was trying to use TimeSpan but I want the messagebox to display a message. How to use if statement in this matter?
DateTime startDate = (DateTime)datePreviDate.Value;
DateTime endDate = (DateTime)datecurrentTime.Value;
TimeSpan ts = endDate.Subtract(startDate);
//Here i want to put if statemnet like
//if the difference of days are less than 2 AND PREVTIME + CURRENT TIME
//IS LESS THEN 24
//then MessageBox.Show.("you CANNOT CHANGE THE DATE")
//else MessageBox.Show.("you APPOINTMENT HAS BEEN CHANGED")
MessageBox.Show(ts.Days.ToString());
form image here
It's kind of hard to understand what you want. But this might help you. I am assuming "PREVTIME" and "CURRENTTIME" are assigned previously. I'm also just turning your comments into logic. Not sure if this is what you meant.
DateTime start = (DateTime)datePreviDate.Value;
DateTime end = (DateTime)datecurrentTime.Value;
var timespan = end - start
var totalTime = PREVTIME + CURRENTTIME;
if(timespan.TotalDays > 2 && totalTime < 24){
MessageBox.Show("You Cannot Change The Date");
//Continue Code Here
} else {
MessageBox.Show("Your Appointment Has Been Changed");
//Continue Code Here
}

C# can't compare two datetimes properly

I'm new to C# and I'm trying to write a simple console application. I have two datetimes but I can't get the message Same, It keeps printing Different.
I also print the two datetimes in the console to know if they are different, but even when the system time is the same it doesn't satisfy the condition.
static void Main(string[] args)
{
while (true)
{
Thread.Sleep(1000);
DateTime dt1 = DateTime.Now;
DateTime dt2 = DateTime.Parse("06:30:00 AM");
if (TimeSpan.Compare(dt1.TimeOfDay, dt2.TimeOfDay) == 0)
{
Console.WriteLine("Same");
}
else
{
Console.WriteLine("Different");
}
Console.WriteLine(dt1);
Console.WriteLine(dt2);
}
}
DateTime has a resolution down to ticks, even though by default they're only printed to seconds in most cultures.
If you print dt1.ToString("o") and the same for dt2, you'll see that even if they're equal to the second, they may well vary in sub-second amounts. That explains why your current code can print "different" but then still print the same value for the next two lines.
A DateTime carries alot more precision than seconds, it is based on ticks, where each tick is 100 nanoseconds. So even if the DateTime.Now matches in hours minutes and seconds, it will be way off in ticks.
You'd be better off using > or < when you attempt to compare. Or do (a - b) < some timespan! Something like:
DateTime dt1 = DateTime.Now;
DateTime dt2 = DateTime.Parse("06:30:00 AM");
bool matches = ( dt2 - dt1 ).Duration() < TimeSpan.FromMilliseconds( 100 ); // matches if dt1 and dt2 are within 0.1s
The .Duration() call is needed to get an absolute time span that can't be negative. Note that you should never use this method for something like an alarm, your system could briefly freeze (due to a multitude of possibilites) and you'd miss it.
Your current comparison would compare Ticks for both DateTime object. If you want to compare Hour, Minute and seconds then have a check like:
if (dt1.TimeOfDay.Hours == dt2.TimeOfDay.Hours &&
dt1.TimeOfDay.Minutes == dt2.TimeOfDay.Minutes &&
dt1.TimeOfDay.Seconds == dt2.TimeOfDay.Seconds)

Regular DateTime question

I'm writing a service but I want to have config settings to make sure that the service does not run within a certain time window on one day of the week. eg Mondays between 17:00 and 19:00.
Is it possible to create a datetime that represents any monday so I can have one App config key for DontProcessStartTime and one for DontProcessEndTime with a values like "Monday 17:00" and "Monday 19:00"?
Otherwise I assume I'll have to have separate keys for the day and time for start and end of the time window.
Any thoughts?
thanks
You could use a utility that will parse your weekday text into a System.DayOfWeek enumeration, example here. You can then use the Enum in a comparison against the DateTime.Now.DayOfWeek
You can save the day of the week and start hour and endhour in your config file, and then use a function similar to the following:
public bool ShouldRun(DateTime dateToCheck)
{
//These should be read from your config file:
var day = DayOfWeek.Monday;
var start = 17;
var end = 19;
return !dateToCheck.DayOfWeek == day &&
!(dateToCheck.Hour >= start && dateToCheck.Hour < end);
}
You can use DayOfTheWeek property of the DateTime.
And to check proper time you can use DateTime.Today (returns date-time set to today with time set to 00:00:00) and add to it necessary amount of hours and minutes.
The DateTime object cannot handle a value that means all mondays. It would have to be a specific Monday. There is a DayOfWeek enumeration. Another object that may help you is a TimeSpan object. You could use the DayOfWeek combined with TimeSpan to tell you when to start, then use another TimeSpan to tell you how long
This is very rough code, but illustrates that you can check a DateTime object containing the current time as you wish to do:
protected bool IsOkToRunNow()
{
bool result = false;
DateTime currentTime = DateTime.Now;
if (currentTime.DayOfWeek != DayOfWeek.Monday && (currentTime.Hour <= 17 || currentTime.Hour >= 19))
{
result = true;
}
return result;
}

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