I'd like to use loop while left mousebutton is pressed:
private void Loop_MouseDown(object sender, MouseEventArgs e)
{
while (e.Button==MouseButtons.Left)
{
//Loop
}
}
I can't use solution from this thread:
C# how to loop while mouse button is held down
because I'm sending via RS232 data and using timer with it's own interval doesn't work. Also any solution from this topic doesn't work for me.
It can't also work one like here:
if (e.Button == MouseButtons.Left)
{
//loop
}
This solution also doesn't work:
bool isLooping = false;
//on mouse down
private void myControl_MouseUp(object sender, System.Windows.Forms.MouseEventArgs e) {
isLooping = true;
runLoop();
}
//on mouse up event
private void myControl_MouseUp(object sender, System.Windows.Forms.MouseEventArgs e) {
isLooping = false;
}
//This is the main loop you care about. Put this in your application
//This should go in its own thread
void runLoop() {
while (isLooping) {
//do stuff
}
}
because calling runLoop would block the thread, and so the MouseUp event would never fire.
So how to make it work correctly?
Use a BackGroundWorker. Perfect for your problem.
Put the loop function in the worker and start / stop the worker on mouse events.
If using a timer won't work, you'll need to send the data on a different thread, and signal that thread from the MouseUp handler.
The correct way to do this would be to put the rs-232 send function into a separate thread so the UI will remain responsive, then you can start and stop it when the mouse events change.
This page might be useful:
http://www.yoda.arachsys.com/csharp/threads/winforms.shtml
These scenarios are very complicated to implement - see your handlers and boolean variables for storing the state.
I would suggest to use Reactive Extensions.
Edit:
It will probably be slightly over-engineered (I don't know if this is the only scenario Elfoc wants to implement). In Rx you can create observable sequence of events
var mouseDown = Observable.FromEvent<MouseButtonEventArgs>(source, "MouseDown");
var mouseUp = Observable.FromEvent<MouseButtonEventArgs>(image, "MouseUp");
var mouseMove = from evt in Observable.FromEvent<MouseEventArgs>(image, "MouseMove")
select evt.EventArgs.GetPosition(this);
use LINQ-to-Rx to query and filter the events
var leftMouseDown = from evt in mouseDown
where evt.LeftButton == MouseButtonState.Pressed
select evt;
and compose it using Rx operators - until any mouse up event is raised take all the positions while left mouse is down
var q = from position in leftMouseDown
from pos in mouseMove.Until(mouseUp)
select new { X = pos.X - imageOffset.X, Y = pos.Y - imageOffset.Y };
Finally, subscribe to the observable sequence of positions and do your stuff
q.Subsribe(value => { ... });
Slightly modified from the code here.
Related
I needed a small function that will wait for the left mous button to be released, and will not be based on the MouseUp event.
In many cases when we need this, we simply write an event handler for the MouseUp event.
It's simple, and it works.
There are however cases, where using the MouseUp event will not be useful,
such as when we are already in another (different) event handler,
and the left mouse button might be pressed when this event handler is called, and we need to wait for it to be released.
(the goal is to have a single flow of code, and not have to split it between several places which might already be occupied with another code)
I implemented it this way:
public void WaitForMouseUp()
{
while( (Control.MouseButtons&MouseButtons.Left)!=0 )
Application.DoEvents();
}
It works,
you can use it for example when you are in the event handler for the Control.Enter event,
and if the control was entered via the mouse, then this function will block until the mouse button is released.
I only worry about one thing:
I am using Application.DoEvents() there, and I wonder if there another way instead of using Application.DoEvents().
(Application.DoEvents(); has disadvantages of possible reentrancy, and so, so for this reason I try to minimize using it, whenever possible)
Anyone has an idea with what I can substitute the Application.DoEvents() part?
Here's an awesome way to do what you're asking. Use Microsoft's Reactive Extensions to make a single line of code do everything you want.
The reactive extensions provide a whole lot of operators that can be applied to events.
So first some basic observables that directly relate to normal control events:
var mouseEnters =
Observable
.FromEventPattern(
h => button1.MouseEnter += h,
h => button1.MouseEnter -= h);
var mouseLeaves =
Observable
.FromEventPattern(
h => button1.MouseLeave += h,
h => button1.MouseLeave -= h);
var mouseUps =
Observable
.FromEventPattern<MouseEventHandler, MouseEventArgs>(
h => button1.MouseUp += h,
h => button1.MouseUp -= h);
Now we need a query that will fire only once when the mouse up occurs, but only if the mouse has entered the button1, but only before it leaves.
var query =
mouseEnters
.Select(me => mouseUps.Take(1).TakeUntil(mouseLeaves))
.Switch();
Now to subscribe to the event to be able to handle it:
var subscription =
query
.Subscribe(ep =>
{
/*
this code runs for the first mouse up only
after each mouse enter on `button1`
unless the mouse leaves `button1`
*/
});
It now because very simple to unsubscribe as the type of subscription is IDisposable. So you simply call subscription.Dispose();.
Just NuGet "Rx-WinForms" to get the bits for your project.
In fact what #Kai Brummund is suggesting is a variation of my answer to Force loop to wait for an event. Adjusting the code from there for MouseUp is simple as
public static class Utils
{
public static Task WhenMouseUp(this Control control)
{
var tcs = new TaskCompletionSource<object>();
MouseEventHandler onMouseUp = null;
onMouseUp = (sender, e) =>
{
control.MouseUp -= onMouseUp;
tcs.TrySetResult(null);
};
control.MouseUp += onMouseUp;
return tcs.Task;
}
}
and the usage is
Control c = ...;
await c.WhenMouseUp();
The same technique can be used for any event.
If You wan't to write a flow within a single method, you can make an awaitable using a TaskCompletionSource.
Your flow:
await MouseUp();
...
private Task MouseUp() {
_tcs = new TaskCompletionSource();
return _tcs.Task;
}
public ... OnMouseUpEvent() {
_tcs?.SetResult(true);
}
Sorry for Pseudo code, will update this once I get something other than a mobile.
OT: Commenters: Think outside of the Box!
I needed a small function that will wait for the mouse's left button to be released.
No you don't. WinForms GUI programming is event driven, asynchronous. You should use the MouseUp event to detect the mouse button's release. This does mean that you need to implement your logic using state based asynchronous techniques, rather than the synchronous model that you crave.
In my WPF application, I have an event handler that gets called on the MouseEnter event of my UI element:
myUiElement.MouseEnter += myEventHandler
I would like to throttle myEventHandler so it doesn't get called more than once every second. How can I do this? Is Rx the best approach just for this? I'm using .NET 4.0 if it makes a difference.
Also, I need to make sure that the MouseLeave event always gets called before the next MouseEnter event; do I need to manage this on my own? Or is the framework already designed so that MouseLeave events will always be called before the next MouseEnter event? What if I have asynchronous code in these event handlers?
Using Rx, you want to use the Sample method or Throttle.
Something like this should work (untested):
Observable
.FromEventPattern<TextChangedEventArgs>(myUiElement, "MouseEnter")
.Sample(TimeSpan.FromSeconds(1))
.Subscribe(x => ... Do Stuff Here ...);
The difference between Sample and Throttle is that Sample will take a value every 1 second no matter when the last value was taken, whereas Throttle will take a value and then wait another 1 second before taking another.
It probably depends on what you are shooting for...
You could use reactive extensions, but you could accomplish this just as easily with a timer.
Set a flag along with a Timer. When the timer tick event fires, set the flag to false, disable the timer, and run the code for your event. Then, in your control event handlers, have the handler code skipped if the flag is set.
bool flag;
DispatcherTimer timer;
public constructor()
{
timer = new DispatcherTimer();
timer.Interval = TimeSpan.FromSeconds(1);
timer.Tick += (s,e) => {
flag = false;
timer.Stop()
DoThrottledEvent();
}
}
void mouse_enter(object sender, MouseEventArgs args)
{
if(!flag)
{
flag = true;
timer.Start();
}
}
void DoThrottledEvent()
{
//code for event here
}
Reactive extensions introduces an extra dependency, but they are a bit of fun. If you are interested, go for it!
Another approach would be to use a private field to keep track of the "time" when the last mouse event occurred, and only continue processing if that time was more than one second ago.
DateTime _lastMouseEventTime = DateTime.UtcNow;
void OnMouseEnter(object sender, MouseEventArgs e)
{
DateTime now = DateTime.UtcNow;
if (now.Subtract(_lastMouseEventTime).TotalSeconds >= 1)
{
// do stuff...
}
_lastMouseEventTime = now;
}
This ensures that "stuff" gets done at least one second apart, which is what I think you were asking for.
well, I'm writing a bot that will use certain coordinates on screen and then will simulate 15 clicks on them (every click with different coordinates). I already made it work with coordinates I entered manually on the code but now I need a way to record those coordinates. What i wanted to do is: the users press a button, then the program shows a messagebox saying "right click the main menu", the user right clicks that and those coordinates will be recorded on an array, then the program will show a second messagebox asking to right click the next button and so... My problem is that I don't know how to make the method wait for the user to right click to continue.
I tested my program by making an event that would trigger everytime I right click and show the coordinates in a messagebox, using a UserActivityHook class with contains the event OnMouseActivity:
UserActivityHook actHook;
void MainFormLoad(object sender, System.EventArgs e)
{
actHook = new UserActivityHook();
// crate an instance with global hooks
// hang on events
actHook.OnMouseActivity+=new MouseEventHandler(MouseMoved);
}
public void MouseMoved(object sender, MouseEventArgs e)
{
if (e.Clicks > 0)
{
if (e.Button.Equals(MouseButtons.Right))
{
MessageBox.Show("X:" + e.X + " Y:" + e.Y);
}
}
}
I've trying to do something like:
private void button1_Click(object sender, EventArgs e)
{
RecordMacro(cords, 1);
}
public void RecordMacro(int coordinates[][], int slotnumber){
MessageBox.show("Right click main menu");
//saves coordinates on [0][0] and [0][1]
WaitForRightClickAndSaveCords(coordinates[][]);
MessageBox.show("Right click resupply button");
//saves coordinates on [1][0] and [1][1]
WaitForRightClickAndSaveCords(coordinates[][]);
...
}
I'm still a newbie and this is my first question in StackOverflow (I usually find an answer browsing here and don't have the need to ask myself) so I'll gladly accept any critics.
This is easiest to implement using C# 5.0's asynchrony model. We'll start out by creating a method that will generate a Task that will be completed when your conditions are met. It will do this by creating a TaskCompletionSource, adding a handler to the event, and marking the task as completed in the handler. Throw in some boilerplate code to make sure the handler is removed when done, return the Task from the completion source, and we're set:
public static Task<Point> WhenRightClicked(this UserActivityHook hook)
{
var tcs = new TaskCompletionSource<Point>();
MouseEventHandler handler = null;
handler = (s, e) =>
{
if (e.Clicks > 0 && e.Button == MouseButtons.Right)
{
tcs.TrySetResult(new Point(e.X, e.Y));
hook.OnMouseActivity -= handler;
}
};
hook.OnMouseActivity += handler;
return tcs.Task;
}
Now you can write:
public async void RecordMacro(int[][] coordinates, int slotnumber)
{
MessageBox.Show("Right click main menu");
Point mainMenuPosition = await actHook.WhenRightClicked();
MessageBox.Show("Right click resupply button");
Point resupplyButtonPosition = await actHook.WhenRightClicked();
}
There are a myriad number of ways to make this work, none of which you should remotely do. The reason is, that assuming you managed to stop execution of the thread with WaitForRightClick, you would be blocking the UI thread!
By doing that, you prevent the user from being able to click on the element you want (among lots of other reasons to never block the UI thread).
You could thread it or use asynchornous methods, as Servy suggests. This blocks the method (or executes it asynchronously) without blocking the UI thread itself.
While more complex, you could also queue up a bunch of object representing a "ClickTarget". Then, you would listen on the right-click event and record the associated coordinates with the current ClickTarget, dequeue to get the next instruction, and so on.
The complete code would be too long for StackOverflow, but to give you some ideas:
public class ClickTarget
{
Point Coordinates {get; set;}
String TargetName {get; set;}
}
Queue<ClickTarget> clickTargets;
//Obviously you instantiate/populate this somewhere
private void onRightClick(...)
{
ClickTarget target = clickTargets.Dequeue();
target.Coordinates = clickLocation;
MessageBox.Show("Please click on " + clickTargets.Peek().TargetName);
}
I have a sub which starts one of two timers (depending on 'zone' condition). This sub called 'CheckAndActivateRelays' is itself called by a Serial Port _DataReceived event. I am inserting break points to help me troubleshoot and am seeing that the tmrSoundSirensAfterDelay.Start() line is being executed successfully with the status of the timer even changing to enabled. However the associated Tick event never executes any of the code contained within it.
If I do the same thing by calling the sub from within button24's click event, it works perfectly. Everything is on the same Form with no threaded processes.
Anyone? Thanks
private void checkAndActivateRelays(int zoneNumber)
{
if (globalFullAlarmSet || globalNightAlarmSet || globalDoorsAlarmSet)
{
if (zoneNumber == 1) //Entry zone
{
//kick off a timer after delay specified in Settings1 file,
if (Settings1.Default.alarmSirenDurationInMinutes != 0)
{
//activates the relays if global alarm flags are still set to true
//(i.e. user has not entered code in time)
globalAlarmEntryDurationTicks = 0;
tmrSoundSirensAfterDelay.Start();
}
}
else //If any other zone is activated during alarm set condition
{
if (Settings1.Default.alarmSirenDurationInMinutes != 0)
{
//Output to relays 1 & 2
spIOCard.Write("~out10=1~");
spIOCard.Write("~out11=1~");
//then close after duration from Settings1 file
globalAlarmSirenDurationTicks = 0;
tmrSoundSirens.Start();
}
}
}
}
private void tmrSoundSirensAfterDelay_Tick(object sender, EventArgs e)
{
globalAlarmEntryDurationTicks = globalAlarmEntryDurationTicks + 1;
if (globalAlarmEntryDurationTicks == Settings1.Default.alarmEntryDelayInSeconds) //Value from Settings1 file
{
spIOCard.Write("~out10=1~");
spIOCard.Write("~out11=1~");
globalAlarmEntryDurationTicks = 0;
tmrSoundSirensAfterDelay.Stop();
tmrSoundSirens.Start();
}
}
private void tmrSoundSirens_Tick(object sender, EventArgs e)
{
globalAlarmSirenDurationTicks = globalAlarmSirenDurationTicks + 1;
if (globalAlarmSirenDurationTicks == (Settings1.Default.alarmSirenDurationInMinutes * 5)) //*60 Value from Settings1 file
{
spIOCard.Write("~out10=0~");
spIOCard.Write("~out11=0~");
globalAlarmSirenDurationTicks = 0;
tmrSoundSirens.Stop();
}
}
private void button24_Click(object sender, EventArgs e)
{
globalFullAlarmSet = true;
checkAndActivateRelays(1);
}
Serial Port Data Received Code:
private void spIO_DataReceived(object sender, System.IO.Ports.SerialDataReceivedEventArgs e)
{
RxString = spIOCard.ReadExisting();
if (RxString == "~in00=1~")
{
checkAndActivateRelays(1);
button10.BackColor = System.Drawing.Color.Red;
}
if (RxString == "~in00=0~")
{
button10.BackColor = System.Drawing.Color.LightGray;
}
if (RxString == "~in01=1~")
{
checkAndActivateRelays(2);
button11.BackColor = System.Drawing.Color.Red;
}
if (RxString == "~in01=0~")
{
button11.BackColor = System.Drawing.Color.LightGray;
}
if (RxString == "~in02=1~")
{
button12.BackColor = System.Drawing.Color.Red;
}
if (RxString == "~in02=0~")
{
button12.BackColor = System.Drawing.Color.LightGray;
}
}
Something to think about since you are using the DataReceivedEvent. According to MSDN it is raised on a secondary thread. This is probably causing your issue.
The DataReceived event is raised on a secondary thread when data is
received from the SerialPort object. Because this event is raised on a
secondary thread, and not the main thread, attempting to modify some
elements in the main thread, such as UI elements, could raise a
threading exception. If it is necessary to modify elements in the main
Form or Control, post change requests back using Invoke, which will do
the work on the proper thread.
Since calling Start() is not the problem the timer setup is where you need to look. Make sure you handle the tick event AND set an interval.
myTimer.Tick += new EventHandler(TimerEventProcessor);
// Sets the timer interval to 5 seconds.
myTimer.Interval = 5000;
myTimer.Start();
The key here is that you are doing this in the SerialPort DataReceived event. This event is fired on a separate thread. Thats important because you probably registered for the Tick event on the main thread, but you start the timer on a different one. You'll need to register the Tick event in the checkAndActivateRelays function. Then it should be happy.
The DataReceived event is raised on a secondary thread when data is received from the SerialPort object. Because this event is raised on a secondary thread, and not the main thread, attempting to modify some elements in the main thread, such as UI elements, could raise a threading exception. If it is necessary to modify elements in the main Form or Control, post change requests back using Invoke, which will do the work on the proper thread.
I'm using a timer to reset a lable I use as a warning box. Basically, if the user does something (more specifically, something goes wrong, ex : He uses a word not recognized by the program), this catches what went wrong early and returns to him what happened so he can change the input.
The reset blanks out the label after 5 seconds to prevent him from seeing something like "please do not use chinese characters" and maybe still thinking an old error is still up. This is what I got reading the invoke (since I hear begininvoke requires an endinvoke, I chose invoke).
private void lblWrn_TextChange(object sender, EventArgs e)
{
Timee = new System.Timers.Timer(5000);
Timee.Elapsed += new ElapsedEventHandler(timerClearWrn);
Timee.Enabled = true;
}
string empty = "";
private void timerClearWrn(object sender, ElapsedEventArgs elapsed)
{
lblWrn.Invoke(new Action<Label>(lblWrn), new object[] { lblWrn, "" });
}
I am not too sure where I am going wrong with this, and looking up examples, cannot figure out which part to change. Can someone explain to me the error or invoke a bit more?
If it's a Windows Forms application, use System.Windows.Forms.Timer, then you don't need Invoke, as the timer callback is executed on the main thread.
Also, don't create a new timer on every text change.
Actually, Control.BeginInvoke does not need an EndInvoke; it is Delegate.BeginInvoke that does.
First, I would also recommend using a Windows.Forms.Timer, since it looks like you are using winforms - that will automatically fire on the UI thread, making all the problems go away - just run the code you want to run in the handler (don't use Invoke etc)
The problem in your example is that the parameters don't match; an Action<> expects a method name (more accurately: a method group) to be invoked, and the parameters in the array must be suitable. Since you don't show the method you plan to invoke, I can't help there - but lblWarn isn't a method (it is a field).
on this line
lblWrn.Invoke(new Action(lblWrn), new object[] { lblWrn, "" });
shouldn't the bold part be a function and not a object?
You have a few options. Option 1 is a little clunky. Options 2 and 3 are better.
Option 1: Continue with general strategy of using Control.Invoke but use code that calls Invoke correctly, disable auto resetting of the timer, and removes the event handler.
private void lblWrn_TextChange(object sender, EventArgs e)
{
var Timee = new System.Timers.Timer(5000);
Timee.Elapsed += this.timerClearWrn;
Timee.AutoReset = false; // Raise the Elapsed event only once
Timee.Enabled = true;
}
private void timerClearWrn(object sender, ElapsedEventArgs elapsed)
{
lblWrn.Invoke(
(MethodInvoker)(()=>
{
lblWrn.Text = "";
}), null);
var Timee = (System.Timers.Timer)sender;
Timee.Elapsed -= this.timerClearWrn;
}
Option 2: Use a System.Windows.Forms.Timer instead of System.Timers.Timer.
Option 3: Use the SynchronizingObject property of System.Timers.Timer. This is my preferred option when timers are to be created and used dynamically from a UI thread.
private void lblWrn_TextChange(object sender, EventArgs e)
{
var Timee = new System.Timers.Timer(5000);
Timee.Elapsed += this.timerClearWrn;
Timee.AutoReset = false; // Raise the Elapsed event only once
Timee.SynchronizingObject = this; // Tell the Timer to raise the Elapsed event on the UI thread
Timee.Enabled = true;
}
private void timerClearWrn(object sender, ElapsedEventArgs elapsed)
{
lblWrn.Text = "";
var Timee = (System.Timers.Timer)sender;
Timee.Elapsed -= this.timerClearWrn;
}