Develop Reference

c# Detect mouse clicks anywhere (Inside and Outside the Form)

Is this possible to detect a mouse click (Left/Right) anywhere (Inside and Outside the Form) in an if statement? And if it's possible, how?
if(MouseButtons.LeftButton == MouseButtonState.Pressed){
...
}

Here is a starter, if I understood your needs of "clicking from outside the window" and Hans Passant's suggestion doesn't fit your needs. You might need to add an event handler for Form1_Click.
CAUTION: This code is provided to illustrate the concept. The threading synchronization in this sample is not 100% correct. Check the history of this answer for an attempt at a more "threading correct" one that sometimes throws exceptions. As an alternative, to get rid of all threading issues, you could have the task in StartWaitingForClickFromOutside be instead always running (aka be always in "listen" mode) as opposed to trying to detect the "within the form" or "outside the form" states and starting/stopping the loop accordingly.
using System;
using System.Threading;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace WindowsFormsApp1
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
this.MouseLeave += Form1_MouseLeave;
this.Leave += Form1_Leave;
this.Deactivate += Form1_Deactivate;
this.MouseEnter += Form1_MouseEnter;
this.Activated += Form1_Activated;
this.Enter += Form1_Enter;
this.VisibleChanged += Form1_VisibleChanged;
}
private AutoResetEvent are = new AutoResetEvent(false);
// You could create just one handler, but this is to show what you need to link to
private void Form1_MouseLeave(object sender, EventArgs e) => StartWaitingForClickFromOutside();
private void Form1_Leave(object sender, EventArgs e) => StartWaitingForClickFromOutside();
private void Form1_Deactivate(object sender, EventArgs e) => StartWaitingForClickFromOutside();
private void StartWaitingForClickFromOutside()
{
are.Reset();
var ctx = new SynchronizationContext();
var task = Task.Run(() =>
{
while (true)
{
if (are.WaitOne(1)) break;
if (MouseButtons == MouseButtons.Left)
{
ctx.Send(CLickFromOutside, null);
// You might need to put in a delay here and not break depending on what you want to accomplish
break;
}
}
});
}
private void CLickFromOutside(object state) => MessageBox.Show("Clicked from outside of the window");
private void Form1_MouseEnter(object sender, EventArgs e) => are.Set();
private void Form1_Activated(object sender, EventArgs e) => are.Set();
private void Form1_Enter(object sender, EventArgs e) => are.Set();
private void Form1_VisibleChanged(object sender, EventArgs e)
{
if (Visible) are.Set();
else StartWaitingForClickFromOutside();
}
}
}
If I understood you incorrectly, you might find this useful: Pass click event of child control to the parent control

When user clicks outside the form control, it losses the focus and you can make use of that.which means you have to use the _Deactivate(object sender, EventArgs e) event of the form control to make this work. Since which will trigger when the form loses focus and is no longer the active form. Let Form1 be the form, then the event will be like the following:
private void Form1_Deactivate(object sender, EventArgs e)
{
// Your code here to handle this event
}

One method is to cover the entire screen with a borderless form with the properties set to transparent (a few percent above completely transparent, not sure if total transparency works but you won't notice the difference) and also set to topmost. Then use the events from the form. As soon as a click is detected this will not affect anything underneath the form (which in my application is something I want to happen) but the form could be closed and another mouse click simulated a fraction of a second later to activate the controls that are underneath. I had no problem using the windows API to use mouse hooks in VB6 but cannot seem to find something that works in c# with the 2019 version of .NET so this is a good workaround. Of course to be really clever you could use an irregular forms method to make the transparent form the same shape as the mouse and follow it.
Note: I have just found the complete code to do it using hooks that mere mortals can get up and running at once! KeyboardMouseHooks C# Library - CodePlex Archive
PS if you use my (dumb) method remember to create an escape key or button or you will have to restart your computer unless the form is programmed to disappear for real clicks as suggested!

I know this is late but maybe it helps someone. Using the MouseEventArgs of the MouseUp event of any control you can check for mouse button and wheel among other things. Here is an example.
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
this.MouseUp += Form1_MouseUp;
}
private void Form1_MouseUp(object sender, MouseEventArgs e)
{
if(e.Button == MouseButtons.Left)
{
DoSomething_LeftClick();
}
else if(e.Button == MouseButtons.Right)
{
DoSomething_RightClick();
}
}
private void DoSomething_LeftClick()
{
//Here some code
}
private void DoSomething_RightClick()
{
//Here some code
}
}

Breaking from a loop with button click - C#

I have a question regarding looping with button click event, I've tried many methods & searched many pages in search for a simple answer for the past hour, but the truth is each answer just looks like alien code, probably because I'm still very new to developing.
Here's a simplified version of what I'm trying to do :
private string Message = "Hello";
private void Spam(bool loop)
{
if (loop == true)
{
while (loop == true)
{
MessageBox.Show(Message);
}
}
else { MessageBox.Show("Spamming has stopped !! "); }
}
private void button1_Click(object sender, EventArgs e)
{
Spam(true);
}
private void button2_Click(object sender, EventArgs e)
{
Spam(false);
}
Obviously this isn't my API, or it'd be a useless thing to invent, however, the code itself is long & you guys always ask for "relevant code" (No disrespect), so there it is.
My problem : Breaking out of the spam loop upon clicking button 2, the code to me looks decent enough for the API to figure out, but each time button 1 is clicked, the API freezes.

Use a background worker to do your work. You can use the cancellation feature to break out of it when you're done. Your loop as you have it will block the UI thread when executed syncronously, which is why your GUI becomes unresponsive. Note if you do any interaction with the UI in the do work delegate, you need to marshal back onto the UI thread (via invoke for example).
private BackgroundWorker _worker = null;
private void goButton_Click(object sender, EventArgs e)
{
_worker = new BackgroundWorker();
_worker.WorkerSupportsCancellation = true;
_worker.DoWork += new DoWorkEventHandler((state, args) =>
{
do
{
if (_worker.CancellationPending)
break;
Console.WriteLine("Hello, world");
} while (true);
});
_worker.RunWorkerAsync();
goButton.Enabled = false;
stopButton.Enabled = true;
}
private void stopButton_Click(object sender, EventArgs e)
{
stopButton.Enabled = false;
goButton.Enabled = true;
_worker.CancelAsync();
}
Update 2019:
BackgroundWorker is now largely obsolete, replaced by the async/await feature in later versions of C# which is easier to use. Here is an example of how to achieve the same thing using that feature:
private CancellationTokenSource _canceller;
private async void goButton_Click(object sender, EventArgs e)
{
goButton.Enabled = false;
stopButton.Enabled = true;
_canceller = new CancellationTokenSource();
await Task.Run(() =>
{
do
{
Console.WriteLine("Hello, world");
if (_canceller.Token.IsCancellationRequested)
break;
} while (true);
});
_canceller.Dispose();
goButton.Enabled = true;
stopButton.Enabled = false;
}
private void stopButton_Click(object sender, EventArgs e)
{
_canceller.Cancel();
}

There's one important thing to remember:
While your code is being executed, the user cannot interact with your user interface.
That means: You first need to exit the loop (i.e. return from the Spam method), and then the user can click Button2.
That's a hard truth, because it means you cannot write the code in the way you wanted to. Fortunately, there are a few ways to work around that:
Don't use a loop. Use some kind of timer to do the "spamming". Button1 starts the timer, Button2 stops it. What kind of timer is available depends on the user interface library you use (WinForms has a Timer, WPF has a DispatcherTimer).
Do the "spamming" in a background thread. This will allow your user interface to stay responsive, and you can communicate with the background thread, for example, by setting a volatile Boolean. This, however, is an advanced topic (and can quickly lead to complex synchronization issues), so I suggest that you try the other option first.

When you click button1 the Spam method is called and loop is starting. When you click button2 Spam method is called but it's not the same. It's the second execution, so it will check the condition and won't enter into the loop, but the loop in the first call sill will be running.
You should use a flag and the loop should use that flag to determine whether it should be still running. It should look something like that:
bool run = false;
string message = "This API is not original";
private void Spam()
{
while (run == true)
{
MessageBox.Show(message);
}
}
}
private void button1_Click(object sender, EventArgs e)
{
message = "Hellooo";
flag = true;
Spam();
}
private void button2_Click(object sender, EventArgs e)
{
flag = false;
}

Take a look at this concept:
private bool loop = false;
private void Start()
{
loop = true;
Spam("Some Message??");
}
private void Spam(string message)
{
while (loop)
{
MessageBox.Show("This API is not original");
}
}
private void button1_Click(object sender, EventArgs e)
{
loop = true;
}
private void button2_Click(object sender, EventArgs e)
{
loop = false;
}
However, the user won't be able to press a button if a MessageBox keeps popping up as it takes up the main UI thread. In order to prevent this you could use BackgroundWorker or start a new thread.

c# loop every minute - where to put the code?

Currently I'm moving from java to c# and I'm full of crazy questions.
I'm trying new things on a windows form application and now,I would like to create a loop wich is executing a code every 1 minute,the problem is that I have no idea where to put this code.
For example,the form structure is like:
using System;
namespace Tray_Icon
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
}
private void button1_Click(object sender, EventArgs e)
{
notifyIcon1.ShowBalloonTip(5000);
}
private void notifyIcon1_BalloonTipClicked(object sender, EventArgs e)
{
label1.Text = "Baloon clicked!";
}
private void notifyIcon1_BalloonTipClosed(object sender, EventArgs e)
{
label1.Text = "baloon closed!";
}
private void contextMenuStrip1_Opening(object sender, CancelEventArgs e)
{
}
private void option1ToolStripMenuItem_Click(object sender, EventArgs e)
{
//some code here
}
private void option2ToolStripMenuItem_Click(object sender, EventArgs e)
{
//some code here
}
private void option3ToolStripMenuItem_Click(object sender, EventArgs e)
{
label1.Text = "Option 3 clicked!";
}
private void notifyIcon1_MouseDoubleClick(object sender, MouseEventArgs e)
{
option1ToolStripMenuItem_Click(this, null);
}
private void closeToolStripMenuItem_Click(object sender, EventArgs e)
{
this.Close();
}
private void btnWrite_Click(object sender, EventArgs e)
{
//code here
}
}
}
Where should I put the loop code? :(
Thanks in advance for ANY replay!!!

Add a Timer to your form:
set its Interval property to 60000 (one minute in milliseconds) and Enabled to True:
and attach an event handler to the Timer.Tick event, e.g. by double-clicking the timer in the Forms designer:
private void timer1_Tick(object sender, EventArgs e)
{
// do something here. It will be executed every 60 seconds
}

You would have to add a timer, and set the interval to 1000 miliseconds, and in the OnTick event you add the code with your loop
Timer tmr = null;
private void StartTimer()
{
tmr = new Timer();
tmr.Interval = 1000;
tmr.Tick += new EventHandler<EventArgs>(tmr_Tick);
tmr.Enabled = true;
}
void tmr_Tick(object sender, EventArgs e)
{
// Code with your loop here
}

You can't put any loop code in here.
In your designer look for the Timer control. When you have that, configure it to run every minute and place your code in the Timer_Tick event.
Or create a timer manually in code and respond to the event :) But for starters, doing it by the designer is easier!

Drag a Timer component on the Form and doubleclick it. There you go with the code.
The Timer component runs in the main thread so you can modify UI components without worrying.
Alternatively You could create a System.Timers.Timer, which has it's own thread and has some advantages, but possible caveats when modifying UI components. See http://msdn.microsoft.com/en-us/library/system.timers.timer.aspx

Try to use Background Worker and put the code in the backgroundWorker.DoWork or use a Timer

Use System.Timers.Timer:
System.Timers.Timer aTimer;
{
aTimer = new System.Timers.Timer();
aTimer.Elapsed += new ElapsedEventHandler(OnTimedEvent);
aTimer.Interval = 60000;
aTimer.Enabled = true;
}
private static void OnTimedEvent(object source, ElapsedEventArgs e)
{
Console.WriteLine("The Elapsed event was raised at {0}", e.SignalTime);
}
for using Timer see this tutorial: C# Timer

How you do it in Java platform?
I think Java should be the same with .net.
In fact, a form program is just normal program which contains a event dispatcher. The event dispatcher listen to the UI events and dispatch them to the event handlers. I think all the UI mode should like this, no matter Java or .net platform.
So generally speaking, you have 2 options:
Start the loop at beginning. In this case, you should insert your
code in the constructor of the Form.
Start the loop when user
click the button. In this case, you should insert your code in the
event handler function.
Yes, as others mentioned, you should use the timer. But this should after you know where your code should locate. You also can use a endless loop with a sleep call. But timer is a better solution.

Idea of timer is more better. But If you want to use threads. Then Follow this
Let me assume that You want to do it right from the start of program
You can write in body of function (event in fact) named Form1_Load as
Your actual code is just within while loop other code only to guide
I can guide if you don't know the use of threads in C#
bool button2Clicked = false;
private void Form1_Load(object sender, EventArgs e)
{
// A good Way to call Thread
System.Threading.Thread t1 = new System.Threading.Thread(delegate()
{
while (!button2Clicked)
{
// Do Any Stuff;
System.Threading.Thread.Sleep(60000); //60000 Millieconds=1M
}
});
t1.IsBackground = true; // With above statement Thread Will automatically
// be Aborted on Application Exit
t1.Start();
}

how to generate a SelectionRangeChanged Event Programatically ChartControl WinForms

want to create a selectionRangeChanged event programatically not really getting how to do it
private void btn_10D_Click(object sender, EventArgs e)
{
double varRange = 10;
double var_Sel1 = DatesX[0].ToOADate();
Chart1.ChartAreas["ChartArea1"].CursorX.IsUserEnabled = true;
Chart1.ChartAreas["ChartArea1"].CursorX.IsUserSelectionEnabled = true;
Chart1.ChartAreas["ChartArea1"].CursorX.SelectionColor = Color.LightGray;
Chart1.ChartAreas["ChartArea1"].CursorX.SelectionStart = var_Sel1;
Chart1.ChartAreas["ChartArea1"].CursorX.SelectionEnd = varRange + var_Sel1;
Chart1.ChartAreas["ChartArea1"].CursorX.Position = varRange + var_Sel1;
Chart1.SelectionRangeChanged += new EventHandler<CursorEventArgs>(Chart1_SelectionRangeChanged);
}
void Chart1_SelectionRangeChanged(object sender, CursorEventArgs e)
{
throw new NotImplementedException();
}
thank you

For all events in C# is true that if class creator did not make extra effort to allow event firing form outside of class it is impossible to fire them.
According to MSDN
Chart.SelectionRangeChanged event Occurs when the selection start position or end position is changed.
But from my tests I can see that it is fired only if it is changed by user not program.
If I understand your intention correctly you want to handle those small buttons under your chart and btn_10D_Click method is a click handler for one of them. Try to move this line
Chart1.SelectionRangeChanged += new EventHandler<CursorEventArgs>(Chart1_SelectionRangeChanged);
to your constructor and ensure it is called once (remove it form other handlers). This will ensure your code is executed when user changes selection. If you want to execute same code for your button you should simply extract handler contents to method and call it form button click handler.
void Chart1_SelectionRangeChanged(object sender, CursorEventArgs e)
{
DoSomething(/*some arguments if you need them*/);
}
private void btn_10D_Click(object sender, EventArgs e)
{
\\your code
DoSomething();
}

c# call function from class

now i have the current code o MainUC.cs:
private void tsbNoviRacun_Click(object sender, EventArgs e)
{
if (racunuc == null)
{
racunuc = new RacunUC();
racunuc.Dock = DockStyle.Fill;
Controls.Add(racunuc);
}
racunuc.BringToFront();
The thing i want to do is clean the code from main page/form. I have 2 taskbar and 2 toolbar buttons that are calling the same form (this one above), so i don't want to write the code 4 times. I tried to make new class.cs with properties and do it with return value, but it didn't work. Can someone help me with it, or, is there possiblity to call the same code on current page/form. Something like
private void tsbStariRacuni_Click(object sender, EventArgs e)
{
call tsbNoviRacun();
}
"( this isn't working, i know :p)
EDiT: Oh damn me, thanks guys!

In c# there is no "call" keyword for invoking functions. You just type the name and all required arguments in round brackets.
private void tsbStariRacuni_Click(object sender, EventArgs e)
{
tsbNoviRacun_Click(sender, e);
}

This should do it:
public void tsbNoviRacun()
{
if (racunuc == null)
{
racunuc = new RacunUC();
racunuc.Dock = DockStyle.Fill;
Controls.Add(racunuc);
}
racunuc.BringToFront();
}
private void tsbNoviRacun_Click(object sender, EventArgs e)
{
tsbNoviRacun();
}
You can call that method from all the event handlers you want it to run on. Obviously this function is depended on Controls and DockStyle so you must put it within scope of this.