Hi I have a ObservableCollection getting data in every minute. When it reaches an hour, I would like to clear the first item and move all the items up then adding the new item, thus maintaining it at 60 elements. Does anyone have any idea how to do so?
Here is my code:
public class MainWindow : Window
{
double i = 0;
double SolarCellPower = 0;
DispatcherTimer timer = new DispatcherTimer();
ObservableCollection<KeyValuePair<double, double>> Power = new ObservableCollection<KeyValuePair<double, double>>();
public MainWindow()
{
InitializeComponent();
timer.Interval = new TimeSpan(0, 0, 1); // per 5 seconds, you could change it
timer.Tick += new EventHandler(timer_Tick);
timer.IsEnabled = true;
}
void timer_Tick(object sender, EventArgs e)
{
SolarCellPower = double.Parse(textBox18.Text);
Power.Add(new KeyValuePair<double, double>(i, SolarCellPower ));
i += 5;
Solar.ItemsSource = Power;
}
}
Just count the items in your list and remove the top item if the count equals 60. Then insert the new item like normal.
if (Power.Count == 60)
Power.RemoveAt(0);
Power.Add(new KeyValuePair<double, double>(i, SolarCellPower ));
Also if you Bind your ItemsSource instead of setting it, it will update automatically when the collection changes.
Related
I have this code
Color[] colours = new Color[5]{Color.Red, Color.Blue, Color.Green, Color.Yellow, Color.Black};
public int randGen(int lower, int upper)
{
Random random = new Random();
return random.Next(lower, upper);
}
public PlayGame()
{
InitializeComponent();
}
protected override void OnAppearing()
{
base.OnAppearing();
changeColour();
}
public void changeColour()
{
int milliseconds = randGen(1000, 5000);
int count = 0;
Device.StartTimer(TimeSpan.FromMilliseconds(milliseconds), () =>
{
var layout = new StackLayout { Padding = new Thickness(5, 10) };
var label = new Label { Text = "Time: ", TextColor = Color.Green, FontSize = 25 };
layout.Children.Add(label);
label.Text += milliseconds.ToString();
this.Content = layout;
if (count < 4)
{
BackgroundColor = colours[count];
count++;
milliseconds = randGen(1000, 5000);
return true;
}
else
{
BackgroundColor = Color.Black;
return false;
}
}
);
}
Which has an array of colours. The idea is that every 1-5 seconds (which should be random each time), the background colour should change, and the text should write how long the screen was on for.
Currently, however, the time shown in the text is not reflective of the time each screen shows for, and I have some speculative concern that milliseconds in:
Device.StartTimer(TimeSpan.FromMilliseconds(milliseconds)
doesn't change at all. Any ideas?
this is what I would do - have your timer fire every second (or whatever granularity you need) but only execute your code every X times
using System.Timers;
// these are class variables
Timer timer;
int timecount = 0;
// adjust this dynamically so your code only executes every 1-n seconds
int interval = 1;
// to this wherever you want to start the timer
timer = new Timer();
timer.Elapsed += Timer_Elapsed;
// fire every 1 sec
timer.Interval = 1000;
timer.Start();
// timer event handler
private void Timer_Elapsed(object sender, ElapsedEventArgs e)
{
timecount++;
if (timecount == interval)
{
timecount = 0;
// do other stuff here
}
}
I have been trying to run a very simple application that moves a 20 by 20 pixel square 20 pixels to the right on a canvas every second. I am using a dispatchertimer to fire the event every second.
The problem is that the square doesn't move to the right unless I shake the application window (with my mouse), and it occasionally moves on its own (albeit not every second).
I have already tried reinstalling Visual Studio 2017 and installing it on my SSD and HDD, neither seem to fix the issue.
Here is the full code of the application's MainWindow.xaml.cs
/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
DispatcherTimer timer = new DispatcherTimer();
Rectangle s = new Rectangle();
Point currentPosition = new Point(20, 20);
public MainWindow()
{
InitializeComponent();
timer.Tick += Timer_Tick;
timer.Interval = TimeSpan.FromSeconds(1);
timer.Start();
s.Width = 20;
s.Height = 20;
s.Fill = new SolidColorBrush(Colors.Black);
map.Children.Add(s);
}
public void Timer_Tick(object sender, EventArgs e)
{
RedrawSquare();
}
public void RedrawSquare()
{
map.Children.Clear();
s.Width = 20;
s.Height = 20;
s.Fill = new SolidColorBrush(Colors.Black);
Canvas.SetLeft(s, currentPosition.X += 20);
map.Children.Add(s);
}
}
On the MainWindow.xaml file there is an empty Canvas with the name "map"
Thank you in advance
You don't need to remove and add the Rectangle on each timer tick, or reset its properties each time.
Just increment the value of the Canvas.Left property:
public partial class MainWindow : Window
{
private readonly DispatcherTimer timer = new DispatcherTimer();
private readonly Rectangle s = new Rectangle();
public MainWindow()
{
InitializeComponent();
timer.Tick += Timer_Tick;
timer.Interval = TimeSpan.FromSeconds(1);
timer.Start();
s.Width = 20;
s.Height = 20;
s.Fill = Brushes.Black;
Canvas.SetLeft(s, 0);
map.Children.Add(s);
}
public void Timer_Tick(object sender, EventArgs e)
{
Canvas.SetLeft(s, Canvas.GetLeft(s) + 20);
}
}
The movement would however be much smoother with an animation:
public MainWindow()
{
InitializeComponent();
s.Width = 20;
s.Height = 20;
s.Fill = Brushes.Black;
Canvas.SetLeft(s, 0);
map.Children.Add(s);
var animation = new DoubleAnimation
{
By = 20,
Duration = TimeSpan.FromSeconds(1),
IsCumulative = true,
RepeatBehavior = RepeatBehavior.Forever
};
s.BeginAnimation(Canvas.LeftProperty, animation);
}
You can try setting the DispatcherPriority to Normal.
Instantiate your timer like this:
DispatcherTimer timer = new DispatcherTimer(DispatcherPriority.Normal);
EDIT:
Although this somehow fixed the issue (square was moving without the need to move the window), it's apparently still the wrong answer. I don't know much about the DispatcherTimer, but I recall having changed the priority once but I don't remember why. In any case, it might be helpful to someone else.
I have created a class which generates a random number:
public class DataGenerator
{
public void RandomHRValue()
{
Random random = new Random();
int RandomNumber = random.Next(0, 100);
}
}
I have then created a XAML file and put the following within the Grid:
<TextBlock Name="a" Text="" Width="196" HorizontalAlignment="Center" Margin="183,158,138,56"/>
I haven't done anything to the xaml.cs file. How would I go about putting a random number into that TextBlock every 20 seconds?
You can use DispatcherTimer like this:
public MainWindow()
{
InitializeComponent();
DispatcherTimer timer = new DispatcherTimer();
timer.Interval = new TimeSpan(0, 0, 20);
timer.Start();
timer.Tick += timer_Tick;
}
void timer_Tick(object sender, EventArgs e)
{
DataGenerator dg = new DataGenerator();
a.Text = dg.RandomHRValue().ToString();
}
Also change method type to int:
public int RandomHRValue()
{
Random random = new Random();
int RandomNumber = random.Next(0, 100);
return RandomNumber;
}
I can't comment due to my low reputation, but in response to the other answer, would it not be better to use the following?
InitializeComponent();
DispatcherTimer timer = new DispatcherTimer {Interval = new TimeSpan(0, 0, 5)};
timer.Start();
timer.Tick += timer_Tick;
If this is wrong, can you say why, so I, myself, can get some feedback (btw OP and I are working together on this)
I'm very new to WP8 dev and c#. I'm trying to make a loop that counts up by n on an interval. I want to press a button to increment n.
Here is my code right now:
namespace Petsounds {
public partial class MainPage : PhoneApplicationPage {
float clicks = 0;
float clickers = 0;
float clickerBuyers = 0;
float clickerCost = 5;
float clickerBuyerCost = 500;
long savedTime = DateTime.Now.Ticks / TimeSpan.TicksPerSecond;
bool buyClickerButtonFlag = false;
bool clickButtonFlag = false;
// Constructor
public MainPage() {
InitializeComponent();
//
DispatcherTimer t = new DispatcherTimer();
t.Interval = TimeSpan.FromMilliseconds(10);
t.Tick += (s, e) => startLoop();
t.Start();
}
private void clickButtonOnClick(object sender, RoutedEventArgs e) {
clickButtonFlag = true;
System.Diagnostics.Debug.WriteLine("clicked!" + clicks);
}
private void buyClickerButtonOnClick(object sender, RoutedEventArgs e) {
buyClickerButtonFlag = true;
}
private void startLoop() {
if (true) {
long nowTime = savedTime;
long timePassed = nowTime - savedTime;
//user input
if (clickButtonFlag) {
clickButtonFlag = false;
clicks++;
System.Diagnostics.Debug.WriteLine("clicked!" + clicks);
}
if (buyClickerButtonFlag) {
buyClickerButtonFlag = false;
if (clicks > clickerCost) {
clickers++;
clicks -= clickerCost;
clickerCost *= 1.6F;
}
System.Diagnostics.Debug.WriteLine("clicker bought!" + clickers);
}
//update vars
if (timePassed > TimeSpan.TicksPerSecond) {
savedTime = nowTime;
nowTime = DateTime.Now.Ticks / TimeSpan.TicksPerSecond;
clicks += clickers;
}
//update display
clickCount.Text = clicks.ToString();
buyClickerButtonCost.Text = "Cossst " + clickerCost.ToString();
}
}
}
}
My button's are inconsistent, and if I remove the thread, the buttons are responsive (but of course the counter doesn't work.)
EDIT:
I've changed
DispatcherTimer t = new DispatcherTimer();
t.Interval = TimeSpan.FromMilliseconds(10);
t.Tick += (s, e) => startLoop();
t.Start();
to
Timer myTimer = new Timer(startLoop);
myTimer.Change(1000, 10);
And now get an error:
A first chance exception of type 'System.UnauthorizedAccessException' occurred in System.Windows.ni.dll
on line
clickCount.Text = clicks.ToString();
First of all... you will quickly find that 10ms is not really 10ms... It might not even be that close... If you did 1000ms... that would be expected to be more accurate.
Also, a DispatcherTimer is going to queue up a function call to the GUI thread each interval... which means you are flooding the GUI thread with startLoop() calls. This doesn't give the thread much time to update anything else... like your buttons.
There is a different approach you might want to consider.
If your task is to increment a numeric value when a user touches a button (and have the numbers increase at a steady pace) consider using the RepeatButton.
RepeatButton: Represents a control that raises its Click event repeatedly from the time it is pressed until it is released.
XAML
<!--
Delay: The time, in milliseconds, the RepeatButton waits
when it is pressed before it starts repeating the click action.
Interval: The time, in milliseconds, between repetitions
of the click action, as soon as repeating starts.
-->
<RepeatButton Content='Buy'
Interval='50' Delay='100'
Click='RepeatButton_Click' />
Code
private float buyCounter = 0;
private void RepeatButton_Click(object sender, RoutedEventArgs e) {
buyCounter += 1;
buyClickerButtonCost.Text = buyCounter.ToString();
}
It's like #Andrew said - DispatcherTimer works on UI thread and with so small intervall you are blocking it.
If you want such a small interval you can use Timer on different Thread:
public MainPage()
{
InitializeComponent();
System.Threading.Timer myTimer = new Timer(MyTimerCallback);
myTimer.Change(1000, 10);
}
private static int value = 0;
private static void MyTimerCallback(object state)
{
value++;
}
But you must remember that you use it on different Thread - this Timer has no access to your UI elements (buttons and so on).
EDIT
You convinced me to check it:
static float clicks = 0;
static float clickers = 0;
static float clickerCost = 5;
static long savedTime = DateTime.Now.Ticks / TimeSpan.TicksPerSecond;
static bool buyClickerButtonFlag = false;
static bool clickButtonFlag = false;
public MainPage()
{
InitializeComponent();
first.Click += ShowCounter;
DispatcherTimer t = new DispatcherTimer();
t.Interval = TimeSpan.FromSeconds(5);
t.Tick += ShowCounter;
t.Start();
System.Threading.Timer myTimer = new Timer(MyTimerCallback);
myTimer.Change(10, 10);
}
private void ShowCounter(object sender, EventArgs e)
{
textBlck.Text = clicks.ToString();
}
private static void MyTimerCallback(object state)
{
clicks++; // added to check running
if (true)
{
long nowTime = savedTime;
long timePassed = nowTime - savedTime;
//user input
if (clickButtonFlag)
{
clickButtonFlag = false;
clicks++;
System.Diagnostics.Debug.WriteLine("clicked!" + clicks);
}
if (buyClickerButtonFlag)
{
buyClickerButtonFlag = false;
if (clicks > clickerCost)
{
clickers++;
clicks -= clickerCost;
clickerCost *= 1.6F;
}
System.Diagnostics.Debug.WriteLine("clicker bought!" + clickers);
}
//update vars
if (timePassed > TimeSpan.TicksPerSecond)
{
savedTime = nowTime;
nowTime = DateTime.Now.Ticks / TimeSpan.TicksPerSecond;
clicks += clickers;
}
}
}
I tested it on the device and buttons works.
On the other hand - what's the point of putting a method that waits for a flag buton click, when you can put the job easily to button click event. Let it happen when user clicked button - don't check buton state all the time.
I have a circular gauge(progress bar) with a polygon needle that when i select a number in a list box the needle goes up to that degree to resemble a speed in a car(works just fine)
What i want to do is automatically run through the indexes of the list items(0,1,2,3,....60) so the needle slowly rises till it gets to say 60 speed. Then, hold that for as long as i want so i can move a tack needle and run an odometer accordingly. i have tried to use a timer in a MVC class and use a stop watch. I can select the index 0 -6 but it will only just jump to the last one. I am trying to simulate a car dashboard the best i can...What are your thought?
public partial class MainWindow : Window
{
//DispatcherTimer timer;
List<Double> _items = new List<Double>();
DispatcherTimer timer;
public MainWindow()
{
this.InitializeComponent();
listBox1.ItemsSource = new List<double>() { 0,1,2,3,4,5,10,11,12,13,14, 15, 20, 25, 30, 35, 40 };
checkBox1.IsChecked = true;
park.Foreground = Brushes.Red;
timer = new DispatcherTimer();
timer.Interval = TimeSpan.FromMilliseconds(2500);
timer.Tick += new EventHandler(timer_Tick);
timer.Start();
}
void timer_Tick(object sender, EventArgs e)
{
int second = DateTime.Now.Second;
firstDigitsec = second / 10;
int secondDigitsec = second % 10;
checkBox1.IsChecked = false;
first.Foreground = Brushes.Green;
park.Foreground = Brushes.White;
checkBox2.IsChecked = true;
Stopwatch stopwatch = Stopwatch.StartNew();
listBox1.SelectedIndex = 0;
listBox1.SelectedIndex = 1;
listBox1.SelectedIndex = 2;
listBox1.SelectedIndex = 3;
}
private int _stopw;
public int sw
{
get { return _stopw; }
set
{
_stopw = value;
OnPropertyChanged("");
}
}
private int _firstDigitsec;
public int firstDigitsec
{
get { return _firstDigitsec; }
set
{
_firstDigitsec = value;
OnPropertyChanged("");
/*
if (firstDigitsec < 1)
{
listBox1.SelectedIndex = 0;
}
if (firstDigitsec < 2)
{
*/
}
}
public event PropertyChangedEventHandler PropertyChanged;
protected virtual void OnPropertyChanged(string propertyName)
{
var handler = PropertyChanged;
if (handler != null)
handler(this, new PropertyChangedEventArgs(propertyName));
}
Since you are using WPF this sounds like an excellent candidate for Animation
Use a Binding to bind your Gauge's Progress property to the Progress property in your viewmodel and apply a DoubleAnimation to animate the Progress property from the previous value to the new value