How to have multiple timers in dataGridView each row?

Tommy

Hi everyone,

Please, I need you guys. I’m completely stuck with my code. I’m trying to create an app that has a countdown for user tasks. Once the countdown completed, holds 00:00:00, checks in MySQL, if there’s a new time added for that record. If Time_remain 0, then another timer keep checking every 30 secs it it’s been updated.

I have a dataGridView and data source is MySQL database. MySQL table contains Id, Taskname,Time_Remain (here goes time in format eg. 36000 = 6 mins).

A little bit, how the form should work.

Form loads 1st time > Loads current results from MySQL> If Time_remain is not 0 then timer even for that row starts the countdown.

First, I’d like to know, which method is best to use? Multithread?

I have the whole code to get info from MySQL. I even know, how to do this countdown if I had only one record. However, I cannot work it out, how to create the fallowing:

1) Dynamic timer for each dataGridView result (row), which has a countdown (Time Remaining). NOTE: I don't want to check MySQL every second

2) Have another timer event working, which starts once the countdown on that row reaches 00:00:00

I've been searching online and discovered that this can be done with:

private Dictionary

Or something similar, but I honestly have no clue. I've tried many variations but none of them function like I would like to. Keep in mind, the number of records taken MySQL changes. Not just 4 records, like in the picture.

I don't know, if you guys have more ideas, ways to do this and same time keep application usage (pc cpu, memory) low?

I have attached my project file for you and a screenshot, how the app would look visually.

10 Replies

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Amit Gupta9y ago
Accepted answer
Hey

I think only a timer control will do all your stuffs, there is no need to use any multithreading concept here

Read the steps carefully

1. Take 2 timer controls and set the interval to 1 sec and 30 sec respectively, just disable them at the design time.

2. First load all the respected time remaining onto your datagrid.

3. If all data fetched then start the 1st timer having interval of 1 sec
a) on its timer tick create a parallel for loop that iterate though your datatable.rows.count
b) Fetch the value of that time column and decrease its value
c) At the same time, if the value became 0, start your 2nd timer having an interval of 30 sec.
d) on the 2nd timer tick event fetch and fill your respective time interval from your database (if added)

I think doing that much will help you to accomplish your task.

Good luck
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Amit Gupta9y ago
Hey If you donot wish to use timer2 then you can use thread to fetch data from the database and retrieve the interval if added, have you done something into practice?
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Tommy9y ago
Guys, anybody else is able to suggest me with the solution to this please? Amit Gupta solution works, but when it comes to a 2nd timer, there's a lot of mess. I need something more used in practice.
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Tommy9y ago
Ok, well I was trying to use, what you've suggested regarding timer 1. It felt a litle complicated in writting it, a bit messy code. But your idea regarding that seem to work. Thank you.

But timer 2 is where I'm stuck now. If I understand what you've suggested correctly regarding 2nd timer (starts after time value 0...), it won't work the way I'd like to.

Unless I'm doing something wrong with the code.

I'll explain, how I did it. I set timer 2 tick interval 30 seconds. Since I'm using single timer (not multiple or independent to each query as it was my intention), once timer 1 value decreases to 0 > timer 2 starts. Inside timer 2 tick I have a code checking, if there was new time set in MySQL. If yes, then updates cell with new time, else recalls timer 2 to check again after 30 seconds interval.

The issue is, if I have multiple records from db ending lets say 10 seconds between one another... Records one hits value 0>timer 2 starts 30 seconds interval...
After 10 more seconds another record hits value 0 and call for the same timer 2 (while the previous call is still running for another 20 seconds). Do you understand what I mean?
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Amit Gupta9y ago
Unfortunately, I am noy with my system to do some code for you, I can only hepp you with the logic part currently
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Tommy9y ago
Are you able to help me with the code sample of what you are suggesting please?
You can download my ready code here.
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Amit Gupta9y ago
No need to stop your timer1, lets it be running. Read the first steps again and start code wuth the steps, after doing so far, you will itself understand the process
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Tommy9y ago
Hi again,

Ok, but I think this is where the problem is...

You are suggesting "When data finishes its bounding process then start your 1st timer to decrease the value till 0"

Ok, but once it hits 0 value, then 1st timer stops and 2nd starts.
But how about, if while one record value hits 0 but another record value is still more than 0? I understand I'm already stopping 1st timer as it ticks all the records.
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Amit Gupta9y ago
Are you saying I should have single timer that ticks every second and on each result in dataGridView taken from MySQL I should have that timer every second/every tick reading, how much time remain?

No, fetch your data at form load i.e your taskname and time

When data finishes its bounding process then start your 1st timer to decrease the value till 0, if it became 0 then start your 2nd timer and do your stuff
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Tommy9y ago
Hi Amit,

Thank you for trying to help but I didn't quite understad, what exactly do you mean?
I'm quite new with this so not aware of all terms.

Are you saying I should have single timer that ticks every second and on each result in dataGridView taken from MySQL I should have that timer every second/every tick reading, how much time remain?

About the 2nd timer (30 seconds), I think I get it. But then, how about if row1 time remain is 0>2nd timer starts, at same time row2 time remain was 25 seconds. So once row2 hits 0, timer 2 will only have 5 seconds left. Do you understand, what I mean?

However, maybe again I'm misunderstanding, how to do approach this in the code?

Also, I'm very much concerned about pc usage. It's very important not to have requests to db every second.
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