So, I'm trying to do a simple GUI to make music with Beeps on C#. I've been trying but I'm not sure if it's even possible to make a Console.Beep play as I hold down a button for example.
There's the normal Beep() method that just plays a short beep with a medium frequency and there's an overload Beep(int frequency, int duration). What I want to do is actually play it the whole time I'm holding the button, but obviously I can't previously state the duration.
I'm thinking this isn't possible but maybe there is a way?
This is also my first question on the site, so, hey.
You could do it like this, i just tested it and it works, and does not lock up the form while running.
private void Window_MouseDown_1(object sender, MouseButtonEventArgs e)
{
// Starts beep on background thread
Thread beepThread = new Thread(new ThreadStart(PlayBeep));
beepThread.IsBackground = true;
beepThread.Start();
}
private void PlayBeep()
{
// Play 1000 Hz for max amount of time possible
// So as long as you dont hold the mouse down for 2,147,483,647 milliseconds it should work.
Console.Beep(1000, int.MaxValue);
}
private void Window_MouseUp_1(object sender, MouseButtonEventArgs e)
{
//Aborts the beep with a new 1ms beep on mouse up which finishes the task.
Console.Beep(1000, 1);
}
Related
I have a Windows forms application that I am trying to add accessibility to and have run into an issue with the speech synthesizer where it appears that the SpeechAsyncCancelAll runs in the user interface thread. Performance is totally dependent on the power of the PC.
This can be reproduced with a very simple application in Windows forms.
Create a form and add a numeric up down control. Then use this code:
using System.Windows.Forms;
using System.Speech;
using System.Speech.Synthesis;
namespace WindowsFormsApp8
{
public partial class Form1 : Form
{
SpeechSynthesizer _speech = new SpeechSynthesizer();
public Form1()
{
InitializeComponent();
}
private void numericUpDown1_ValueChanged(object sender, EventArgs e)
{
_speech.SpeakAsyncCancelAll();
_speech.SpeakAsync(numericUpDown1.Value.ToString());
}
}
}
On my development machine which is very powerful it runs without a problem and very fast when you hold down the up arrow. Each value is cancelled so you do not hear anything as the control increments and when you stop pressing the up arrow it announces the last value properly.
However, the minute this is run on a lesser PC, even a core i9 hexacore machine, the repeat on the increment slows to a crawl.
It looks to me that this is running on the user interface thread.
Any suggestions?
Thanks
Don't get yourself tricked by the "Async" in the name of the SpeakAsyncCancelAll() method name. As one can see in the source code of the SpeechSynthesizer and VoiceSynthesis classes, there is quite some synchronous code involved in order to communicate with a background thread that does the actual voice synthesis. This code is actually quite heavy in that it uses multiple lock statements.
A best practice solution for this situation (multiple successive user interactions could create a series of code reactions but in the end we only want the last one) is to not directly start the reaction, but start a timer and only perform the reaction if there was no other user interaction in the meantime.
public partial class Form1 : Form
{
private SpeechSynthesizer _speech = new SpeechSynthesizer();
public Form1()
{
InitializeComponent();
timer1.Interval = 500;
}
private void numericUpDown1_ValueChanged(object sender, EventArgs e)
{
// Reset timer
timer1.Stop();
timer1.Start();
}
private void timer1_Tick(object sender, EventArgs e)
{
timer1.Stop();
_speech.SpeakAsyncCancelAll();
_speech.SpeakAsync(numericUpDown1.Value.ToString());
}
}
You should allow the user to configure the timer interval to chose a good compromise based on their system performance and their individual usage patterns. People who need audio assistance often consider for good reasons a too long delay between user activity and an audio response as wasting their time. So it is important that users can configure such a delay to best fit their individual needs.
Let's assume you have taken Neil's excellent comment into consideration, and checked the repeat rate of the NumericUpDown control on the other PCs "without" calling the speech engine. Good.
Your code looks right. The SpeakAsyncCancelAll and SpeakAsync do not block and are "expected" to be running on a background thread. When I attempted to reproduce the problem (not a shocker) your code works fine on my PC using the test condition you describe. That being the case, maybe you could try a couple of variations on the slim chance that something makes a difference and yields some kind of clue by ruling out some unlikely issues.
Variation 1
Capture the "text to say" and post the work using BeginInvoke. This ensures that nothing could possibly be interfering with the ValueChanged or MouseDown messages from pumping in the message queue.
private void numericUpDown1_ValueChanged(object sender, EventArgs e)
{
// Make 100% sure that the up-down ctrl is decoupled from speak call.
var say = $"{numericUpDown1.Value}";
// Ruling out an unlikely problem
BeginInvoke((MethodInvoker)delegate
{
_speech.SpeakAsyncCancelAll();
_speech.SpeakAsync(say);
});
}
Variation 2
Since you have a suspicion that something is running on the UI thread that shouldn't be, go ahead and give explicit instructions to post it on a background Task. At least we can rule that out.
private void numericUpDown2_ValueChanged(object sender, EventArgs e)
{
// Make 100% sure that the up-down ctrl is decoupled from speak call.
var say = $"{numericUpDown2.Value}";
// Ruling out an unlikely problem
Task.Run(() =>
{
_speech.SpeakAsyncCancelAll();
_speech.SpeakAsync(say);
});
}
Variation 3 - Inspired by NineBerry's answer (added to test code project repo)
/// <summary>
/// Watchdog timer inspired by NineBerry.
/// https://stackoverflow.com/a/74975629/5438626
/// Please accept THAT answer if this solves your issue.
/// </summary>
int _changeCount = 0;
private void numericUpDown3_ValueChanged(object sender, EventArgs e)
{
var captureCount = ++_changeCount;
var say = $"{numericUpDown3.Value}";
Task
.Delay(TimeSpan.FromMilliseconds(250))
.GetAwaiter()
.OnCompleted(() =>
{
if(captureCount.Equals(_changeCount))
{
Debug.WriteLine(say);
_speech.SpeakAsyncCancelAll();
_speech.SpeakAsync(say);
}
});
}
Well the above answers do not solve the issue. However, all the tested computers were dell computers. By default when the OS is installed, Dell installs a sound utility called MaxWaves which allows different audio enhancements. Although all options are off in this utility, it appears that it buffers the sound and when an Async.CancelAll() call comes, it blocks until the sound duration is complete. Therefore everything appears to slow to a crawl.
Uninstalling this utility as well as disabling it as a service corrects the problem.
Everything now works correctly. Thank you for your answers.
I am playing an Audio use Windows Media Player in c# WinForms. I want to display a message at the end of the audio play back.
I have a separate Audio class for playing audio and in the play method I have written:
Player = new WMPLib.WindowsMediaPlayer();
public static void play()
{
Player.controls.play();
Player.PlayStateChange += new WMPLib._WMPOCXEvents_PlayStateChangeEventHandler(Player_PlayStateChange);
}
private void Player_PlayStateChange(int NewState)
{
if ((WMPLib.WMPPlayState)NewState == WMPLib.WMPPlayState.wmppsStopped)
isComplete=true;
}
public static boolean hasCompleted()
{
return isComplete;
}
here isComplete is a boolean variable initialized to false
In my form, the code for my play button is:
//Play my audio
while(!hasCompleted());
//display message
The problem is that when i click the play button, my application goes into an infinite loop.
However when i do this:
while(!hasCompleted())
MessageBox.Show("Playing");
//display message
It works fine.
Why is this happening?
I dont want to display a message while it's playing.
I tried using:
Player.currentMedia.duration
and duration string property for a timer or Thread.sleep application but the value returned by both is always 0.
I also tried giving a delay of 1-2 seconds before calling the duration property but this doesn't work as some of my audio tracks are just 2 seconds long.
It is not the best way to do so since you are in a busy waiting situation which waste a lot of CPU cycles and may not work as you wish. I would recommend you to use "Event". Here you can find a very basic example:
http://www.codeproject.com/Articles/11541/The-Simplest-C-Events-Example-Imaginable
http://msdn.microsoft.com/en-us/library/aa645739(v=vs.71).aspx
I have timer with an interval of 20 ms in Visual C#.
public class Global
{
//Global Vars
public static System.Media.SoundPlayer sound = new System.Media.SoundPlayer(Project.Properties.Resources.tock);
}
private void timer1_Tick(object sender, EventArgs e)
{
Global.sound.PlaySync();
}
My tock.wav plays 70 ms. My Problem is that timer1_tick is waiting till the sound is played and I don't want to short my wav file. Is there any option to play the sound in the background? It might sounds not good, but I will give it a try.
To start the SoundPlayer in a separate thread, simply call Play() instead of PlaySync().
See the documentation for reference.
I am creating a piano in C Sharp and currently I have keyboard keys to play sounds. For example key A plays Note C. problem I am having is there I want to be pressing multiple keys at the same time and have the sound out. obviously I don't want to have to put all combinations in the keyDown class as I will have to make thousands of if statements. Is there anyway around this?
Windows works with an only one message queue, so in each time only a key down message will be handled at a time unit. What you can do is to get all key down events in a short time interval (0.5 seconds for instace), save all key pressed in a list or a queue, then play all sounds according to the keys asynchronically (using threads). I have never have done this before, but I think should works. Hope helps...
EDIT
Ok, let see:
first the list where to save the keys
List<Key> _keys = new List<Key>();
Then start a timer for checking the keys pressed in a time interval:
var t = new System.Timers.Timer(500); //you may try using an smaller value
t.Elapsed += t_Elapsed;
t.Start();
Then the t_Elapsed method (Note that if you are in WPF an DispatcherTimer should be used, this timer is on System.Timers)
void t_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
{
if (_keys.Count > 0)
{
//Here get all keys and play the sound using threads
_keys.Clear();
}
}
And then the on key down method:
void OnKeyDownMethod(object sender, KeyPressedEventArgs e) //not sure this is the name of the EventArgs class
{
_keys.Add(e.Key); //need to check
}
You may try this, hope be helpful.
I'm building an app that uses and scanner API and a image to other format converter. I have a method (actually a click event) that do this:
private void ButtonScanAndParse_Click(object sender, EventArgs e)
{
short scan_result = scanner_api.Scan();
if (scan_result == 1)
parse_api.Parse(); // This will check for a saved image the scanner_api stores on disk, and then convert it.
}
The problem is that the if condition (scan_result == 1) is evaluated inmediatly, so it just don't work.
How can I force the CLR to wait until the API return the convenient result.
NOTE
Just by doing something like:
private void ButtonScanAndParse_Click(object sender, EventArgs e)
{
short scan_result = scanner_api.Scan();
MessageBox.Show("Result = " + scan_result);
if (scan_result == 1)
parse_api.Parse(); // This will check for a saved image the scanner_api stores on disk, and then convert it.
}
It works and display the results.
Is there a way to do this, how?
Thank you very much!
UPDATE:
Theres an event on the scanner API:
Public Event EndScan() // Occurs when the scanned the image.
But I don't know how to use it. Any Idea?
That really depends on how the API works. If scanner_api.Scan() is blocking, then it will sit at that line waiting for a result. Once it gets the result, the if will evaluate. This can cause your UI to become unresponsive, so you often have to implement some sort of threading to do it in the background. I'm guessing from your question that isn't the way this API works.
Another way this could work is with polling. You check every so often to see what the result is. You don't want to check constantly and use up all your resources (such as CPU), so you check at an interval. Sheldon's answer with a Timer achieves this.
At least one more way this may work is with a callback. You send the API a callback function to call when the status has updated. This can be implemented as events (delegate) you tie into or a regular delegate you pass as a parameter. You'll often see these implemented as "OnStatusChanged", "OnCompleted", etc.
Basically, it's down to what the API supports. Polling usually works, the others have to be supported. Check your API documentation for examples if possible.
You can use a timer (see MSDN: Timer class) that periodically checks whether the scan already completed or not.
You can alternatively use an asynchronous call that calls back when the scanning process is finished. Note that this is the more complicated way.
One way would be with a timer. Set the timer to check every few seconds to check the value in scan_result (which would need to be promoted to a class-level variable for this to work).
So, something like:
public class Scanning
{
private System.Timers.Timer aTimer;
short scan_result;
public Scanning()
{
aTimer = new System.Timers.Timer(1000);
// Hook up the Elapsed event for the timer.
aTimer.Elapsed += new ElapsedEventHandler(OnTimedEvent);
}
private void ButtonScanAndParse_Click(object sender, EventArgs e)
{
aTimer.Enabled = true;
scan_result = scanner_api.Scan();
}
private void OnTimedEvent(object source, ElapsedEventArgs e)
{
if (scan_result == 1)
{
aTimer.Enabled = false;
parse_api.Parse(); // This will check for a saved image the scanner_api stores on disk, and then convert it.
}
}
}
(This is untested, of course. YMMV.)