Im making a chat program that saves the messages in files like pub0.zzc, all computers that are using it will be connected to the hard drive that these files are in, so its fine. The method data.Chat.Read(MessageTypes type, string Channel) infinite loops through a try catch statement till it returns the messages. I used this before and works perfectly. But, my code was hard to manage so instead of just putting text boxes into the window and using the code each time, i created a user control (MessageViewer). It works fine, once again when I run it, BUT it freezes VS whenever I try to use the designer on the window housing the control. the probelm isnt the window because when i delete the control its fine. I think the possible errors are at RefreshMessages() and the Refresher_Tick(...)
Refresher.Stop() and .Start() is also not it, worked fine before
so here is the code:
private void Refresher_Tick(object sender, EventArgs e)
{
Refresher.Stop();
int RefreshRate = 4;
bool Live = true;
if (RefreshRateChoice == "Manual")
{
Live = false;
RefreshRate = 1;
}
else if (RefreshRateChoice == "4 ( Default )")
{
Live = true;
RefreshRate = 4;
}
else
{
Live = true;
RefreshRate = Convert.ToInt32(RefreshRateChoice);
}
if (data.Chat.Read(MessageType, ChannelChoice) != ContentPresenter.Text && Live)
{
RefreshMessages();
}
Refresher.Interval = RefreshRate;
Refresher.Start();
}
public void RefreshMessages() {
if (data.Chat.Read(MessageType, ChannelChoice) != ContentPresenter.Text)
{
ContentPresenter.Text = data.Chat.Read(MessageType, ChannelChoice);
}
}
and if you need it:
public static string Read(MessageTypes Type, string Channel)
{
string Loc;
if (Type == MessageTypes.Public && (Channel == "1" || Channel == "2"))
{
return "Can not view this channel, only post to it.";
}
if (Type == MessageTypes.Public)
{
Loc = data.AssetsFolder + "\\pub" + Channel + ".zzc";
}
else if (Type == MessageTypes.Private)
{
Loc = data.AssetsFolder + "\\" + Channel + ".zzpc";
}
else if (Type == MessageTypes.Game)
{
Loc = data.AssetsFolder;
}
else
{
Loc = data.AssetsFolder;
}
while (true)
{
try
{
String MessageList = "";
StreamReader MessageReader = new StreamReader(Loc);
string EncMessages = MessageReader.ReadToEnd();
MessageReader.Dispose();
List<string> EncMsgList = EncMessages.Split(';').ToList();
for (int i = 1; i < EncMsgList.Count; i++)
{
MessageList += data.Encodings.Decrypt(EncMsgList[i], Palettes.Message) + "\n";
}
return MessageList;
}
catch
{
// Do nothing
}
}
}
You say that it "freezes."
In your Read method you have a while(true) loop with an embedded try...catch block, but the catch never returns you from that method. If you keep throwing the same exception, you'll continue to loop over and over which could be where you are freezing.
At least to prove that is the case, put a return in you catch or some diagnostic code to indicate if that is the case.
Related
So, I'm trying to code simple memory game in Windows Forms but I've met a simple problem that somehow I can't pass.
This is a single button code(they all look very similar):
Match CheckForMatches = new Match();
private void Pathfinder_Click(object sender, EventArgs e)
{
CheckForMatches.AddButton(Pathfinder);
CheckForMatches.Matched();
}
(where CheckForMatches object is shared between all buttons in given form)
And here are called methods codes:
public void AddButton(Button newButton)
{
if (firstButtonPressed == null)
{
firstButtonPressed = newButton;
firstButtonPressed.ImageIndex = 0; //uncovering card
}
else
{
secondButtonPressed = newButton;
secondButtonPressed.ImageIndex = 0;
Thread.Sleep(1000);
}
}
public bool Matched()
{
if (firstButtonPressed != null && secondButtonPressed != null )
{
if (firstButtonPressed.Name != secondButtonPressed.Name)
{
if (firstButtonPressed.Text == secondButtonPressed.Text)
{
DisposeButtons();
return true;
}
else
{
NullButtons();
return false;
}
}
else
{
return false;
}
}
else
{
return false;
}
}
Now this method call one of two others, depending if last 2 clicked buttons are a pair or not(basing on their name and text):
This in case of succes disposes buttons and null Match class variables:
public void DisposeButtons()
{
firstButtonPressed.Dispose();
secondButtonPressed.Dispose();
firstButtonPressed = null;
secondButtonPressed = null;
}
This is case of failure covers cards and also nulls Match class variables:
public void NullButtons()
{
firstButtonPressed.ImageIndex = 1; //covering cards
secondButtonPressed.ImageIndex = 1;
firstButtonPressed = null;
secondButtonPressed = null;
}
The point is, no matter where I place Thread.Sleep(1000), user can never see second card he choses. He always see the first one and then, when he choses second one, either both cards are disposed(app is freezing due to that delay) or the first one becomes covered, without uncovering the second one.
EDIT:
I added output to debugger window, so now method AddButton looks like this:
public void AddButton(Button newButton)
{
if (firstButtonPressed == null)
{
firstButtonPressed = newButton;
Debug.WriteLine("Before index chaning: " + firstButtonPressed.ImageIndex);
firstButtonPressed.ImageIndex = 0; //uncovering card
Debug.WriteLine("After index chaning: " + firstButtonPressed.ImageIndex);
}
else
{
secondButtonPressed = newButton;
Debug.WriteLine("Before index chaning: " + secondButtonPressed.ImageIndex);
secondButtonPressed.ImageIndex = 0;
Debug.WriteLine("After index chaning: " + secondButtonPressed.ImageIndex);
Thread.Sleep(1000);
}
}
I can see there, that ImageIndex buttons' property actually changes between 1 and 0. However, in practice, it's only visible when first if block of this method is called. I would be grateful for answering why and how to change that.
Okay, I found out maybe not best solution, but it works. I simply forced button to refresh.
Correct form of AddButton method is:
public void AddButton(Button newButton)
{
if (firstButtonPressed == null)
{
firstButtonPressed = newButton;
Debug.WriteLine("Before index changing: " + firstButtonPressed.ImageIndex);
firstButtonPressed.ImageIndex = 0; //uncovering card
Debug.WriteLine("After index changing: " + firstButtonPressed.ImageIndex);
}
else
{
secondButtonPressed = newButton;
Debug.WriteLine("Before index changing: " + secondButtonPressed.ImageIndex);
secondButtonPressed.ImageIndex = 0;
secondButtonPressed.Refresh();
Debug.WriteLine("After index changing: " + secondButtonPressed.ImageIndex);
Thread.Sleep(500);
}
}
I hope it will be useful for someone one day.
this code is called upon a button click in a windows form and the values are stored after button click and disappear after the event ends and go back to default values but I want the values to remain as i have to use them somewhere else....any suggestions?Also I want to retain the current state of the form and not use a new instance each time
showval function called and the value of variable bitwise is changed there
class Profile{
public bool GetProfileFilter()
{
frmInactiveView frmInactive = new frmInactiveView();
if (frmInactive.btnApplyWasClicked == true || frmInactive.btnCancelWasClicked == false)
{
frmInactive.ShowVal();
MessageBox.Show("bit:" + IBitWise);
MessageBox.Show("ST:" + BegDate);
MessageBox.Show("ET:" + EndDate);
return true;
}
else
{
return false;
}
}
}
enter code here
public partial class FilterView : Form{
Profile profile = new Profile();
private void btnApply_Click(object sender, EventArgs e)
{
btnApplyWasClicked = true;
ShowVal();
status = profile.GetProfileFilter();
profile.ShowMe();
Btn_Enable();
this.Close();
}
public void ShowVal()
{
if (btnApplyWasClicked == true || btnCancelWasClicked == false)
{
if (chkCancel.Checked == true)
{
profile.IBitWise += 2;
}
if (chkDiscon.Checked == true)
{
profile.IBitWise += 1;
}
if (chkVoidwoRes.Checked == true)
{
profile.IBitWise += 4;
}
if (chkVoidwRes.Checked == true)
{
profile.IBitWise += 8;
}
}
}
}
The problem is your form getting instantiated every time when GetProfileFileter is called.
To avoid it, put instance of frmInactiveView under your Profile class. Then value of frmInactiveView would only be renewed when a new Profile is instantiated.
class Profile{
// Keep your form instance here
frmInactiveView frmInactive = new frmInactiveView();
public bool GetProfileFilter()
{
// Don't new it again!
//frmInactiveView frmInactive = new frmInactiveView();
DialogResult result = frmInactive.ShowDialog();
// You may need to take care of dialog result if someone clicked cancel.
if (frmInactive.btnApplyWasClicked == true || frmInactive.btnCancelWasClicked == false)
{
frmInactive.ShowVal();
MessageBox.Show("bit:" + IBitWise);
MessageBox.Show("ST:" + BegDate);
MessageBox.Show("ET:" + EndDate);
return true;
}
else
{
return false;
}
}
}
I’ve created a user control. In the control I have two methods – sending and receiving some data. Those methods also update the data grid located on the user control.
public void RunTX()
{
tx_run = new Thread(new ThreadStart(SendCanFrames));
if (!tx_run.IsAlive)
{
tx_run.IsBackground = true;
tx_run.Start();
}
}
public void RunRX()
{
rx_run = new Thread(new ThreadStart(ReadCanFrames));
if (!rx_run.IsAlive)
{
rx_run.IsBackground = true;
rx_run.Start();
}
}
private void ReadCanFrames()
{
ushort prev_time_stamp = 0;
while (running)
{
if (CanDevice != null)
CanDevice.Read(ref rx_can_msg, 1, ref read_cnt);
if (read_cnt == 1)
{
read_cnt = 0;
dataGridViewCanRx.Rows[0].Cells[0].Value = rx_can_msg[0].Id.ToString("X");
dataGridViewCanRx.Rows[0].Cells[1].Value = rx_can_msg[0].Size.ToString();
dataGridViewCanRx.Rows[0].Cells[2].Value = BytesToString(rx_can_msg[0].Data);
dataGridViewCanRx.Rows[0].Cells[3].Value = (rx_can_msg[0].TimeStamp - prev_time_stamp).ToString();
prev_time_stamp = rx_can_msg[0].TimeStamp;
}
prev_time_stamp = rx_can_msg[0].TimeStamp;
}
}
private void SendCanFrames()
{
if (tx_can_msg.Length == 0) return;
VSCAN_MSG[] l_msgs = new VSCAN_MSG[2];
while (running)
{
for (int i = 0; i < tx_can_msg.Length; i++)
{
if (can_messages[i].CountRun < can_messages[i].CountMax)
{
can_messages[i].TimeStamp1 = DateTime.Now;
interval = can_messages[i].TimeStamp1 - can_messages[i].TimeStamp2;
if (interval.TotalMilliseconds >= can_messages[i].Period)
{
can_messages[i].TimeStamp2 = DateTime.Now;
l_msgs[0] = tx_can_msg[i];
//send CAN frame
CanDevice.Write(l_msgs, 1, ref written_cnt);
// send immediately
CanDevice.Flush();
can_messages[i].CountRun++;
dataGridViewCanTx.Rows[i].Cells[4].Value = can_messages[i].CountRun.ToString();
}
}
}
}
}
I put four user control instances on the main form and start all four controls.
private void buttonStartAll_Click(object sender, EventArgs e)
{
int can_channel;
for (can_channel = 0; can_channel < 4; can_channel++)
{
if (started[can_channel] == false)
{
if (connected[can_channel] == true)
{
switch (can_channel)
{
case 0:
mainform.userControlCan1.RunTX();
mainform.userControlCan1.RunRX();
started[can_channel] = true;
break;
case 1:
mainform.userControlCan2.RunTX();
mainform.userControlCan2.RunRX();
started[can_channel] = true;
break;
case 2:
mainform.userControlCan3.RunTX();
mainform.userControlCan3.RunRX();
started[can_channel] = true;
break;
case 3:
mainform.userControlCan4.RunTX();
mainform.userControlCan4.RunRX();
started[can_channel] = true;
break;
}
}
}
}
}
All is running, however the GUI freezing and data grids updated by jumps. Why?
I recomend you to look at two key points: Invoke and Application.DoEvents.
First one will help you to update your GUI in main thread instead of child threads.
Have a look at : https://learn.microsoft.com/en-us/dotnet/api/system.reflection.methodbase.invoke?view=netframework-4.8
Application.DoEvents() method tells the system to do other waiting jobs without blocking in some loops. Otherwise updating GUI jobs are postponed and GUI is blocked. Here is the information about this method: https://learn.microsoft.com/tr-tr/dotnet/api/system.windows.forms.application.doevents?view=netframework-4.8
private delegate void dlgUpdateRows(object[] rx_can_msg, int tID);
// Write actual type of rx_can_msg instead of object[] in method signature , second parameter should be your thread id if needed
private void UpdateRows(object[] rx_can_msg, int tID =0)
{
try
{
if (this.InvokeRequired)
{
object[] obj = new object[2];
obj[0] = rx_can_msg;
obj[1] = Thread.CurrentThread.ManagedThreadId;
this.Invoke(new dlgUpdateRows(UpdateRows), obj);
}
else
{
//Here update your datagrid using rx_can_msg
}
//This row is important to avoid blocking
Application.DoEvents();
}
catch (Exception ex)
{
//Do error handling
}
}
The program uses two threads: one for collecting the data from USB, and the other writes/displays the data. It seems to work as expected, however, as soon as I minimize/restore any windows on the PC, or press any buttons on the Form, it stops working properly (it stops receiving data). I use link list to keep the data streaming in order. I suspect that maybe the link is lost somewhere because of improper variable declaration. Is there an obvious mistake in my code that could be causing this?
namespace Streamer
{
public class Form1 : System.Windows.Forms.Form
{
Thread tListen;
Thread tDisplay;
public class MY_DATA_BUFFER
{
public byte[] buffer;
public int length;
public MY_DATA_BUFFER nextBuff;
}
private Object thisLock = new Object();
MY_DATA_BUFFER pHead = null;
private static AutoResetEvent DataQueueEvent = new AutoResetEvent(false);
public Form1()
{
// some settings;
}
public unsafe void dataDisplayThread()
{
MY_DATA_BUFFER pWorkingSet = pHead;
if (pWorkingSet == null)
{
// Make sure link list head is initialized...........
do {DataQueueEvent.WaitOne();} while (pHead == null);
// Wait till the two datas are available to write.
if (pHead.nextBuff == null){ DataQueueEvent.WaitOne(); }
if (pWorkingSet == null) { pWorkingSet = pHead; }
}
// Let's start the data write loop
while (bRunning || (pWorkingSet != null))
{
// copy small array to a bigger array
for (int i = 0; i < pWorkingSet.length; i++)
{
pixelValues[pixptr] = pWorkingSet.buffer[i];
pixptr++;
}
if (pixptr >= imWidth * imHeight)
{
pixptr = 0;
// show data in pixelValues
}
// Traverse through the link list data structure.
if (pWorkingSet.nextBuff == null)
{
do
{
if (pWorkingSet.nextBuff == null DataQueueEvent.WaitOne();
lock (thisLock)
{
if (pWorkingSet.nextBuff == null && !bRunning)
break;
}
} while (pWorkingSet.nextBuff == null);
}
// We are good to loop for the next operation
lock (thisLock)
{
pHead = pHead.nextBuff;
pWorkingSet = pHead;
}
}
// All write operation is at completion
pHead = null;
}
public unsafe void XferData(...)
{
MY_DATA_BUFFER tempBuff = null;
for (; bRunning; )
{
// .... do something
// push the data to a link list for
lock (thisLock)
{
MY_DATA_BUFFER newBuff = new MY_DATA_BUFFER();
newBuff.nextBuff = null;
newBuff.buffer = xBufs[k];
newBuff.length = len;
if (tempBuff == null) tempBuff = newBuff;
else
{
tempBuff.nextBuff = newBuff;
tempBuff = newBuff;
}
if (pHead == null) pHead = newBuff;
else
{
DataQueueEvent.Set();
}
}
///////////////////Link List Population completes///////////
Thread.Sleep(0);
} // End infinite loop
}
private void StartBtn_Click(object sender, System.EventArgs e)
{
if (StartBtn.Text.Equals("Start"))
{
// ...
pHead = null;
bRunning = true;
tListen = new Thread(new ThreadStart(XferThread));
tListen.IsBackground = true;
tListen.Priority = ThreadPriority.Highest;
tListen.Start();
tDisplay = new Thread(new ThreadStart(dataDisplayThread));
tDisplay.IsBackground = true;
tDisplay.Priority = ThreadPriority.Highest;
tDisplay.Start();
}
else
{
if (tListen.IsAlive)
{
// ...
bRunning = false;
if (tListen.Join(5000) == false )
tListen.Abort();
tListen = null;
}
if (tDisplay.IsAlive)
{
if (tDisplay.Join(5000) == false )
tDisplay.Abort();
Display = null;
}
}
}
}
}
if (t != null) is always null why help..
when ever i try to get value in the variable name t it always gets in the else part but i am sure that there is valuse in tat variable.
private void button3_Click(object sender, EventArgs e)
{
try
{
if (search=="")
{
}
else
{
if (textBox1.Text=="")
{
MessageBox.Show("Select A Task Or Find One");
}
else
{
search = textBox1.Text;
}
}
if (search != null)
{
t = tasks.OpenTask(search);
if (textBox2.Text!="")
{
short hour = short.Parse(textBox2.Text.Substring(0, 2));
short minute = short.Parse(textBox2.Text.Substring(3, 2));
if (t != null) // this is null dont know why
{
foreach (Trigger tr in t.Triggers)
{
if (tr is StartableTrigger)
{
(tr as StartableTrigger).StartHour = hour;
(tr as StartableTrigger).StartMinute = minute;
}
}
t.Save();
t.Close();
}
tasks.Dispose();
button2.Visible = true;
textBox3.Visible = true;
search = "";
}
else
{
MessageBox.Show("Enter Time ");
}
}
}
catch (Exception b)
{
MessageBox.Show(b.ToString());
// MessageBox.Show("Select A Task From The List ");
}
}
help guys .. well i tried it to debug but didnt get a break through..
t is null because tasks.OpenTask(search) returns null.
Probably there is no task matching your search criteria.
Why are you disposing of tasks in the first place?
Any place in your source ,where you have written something like this MyClass t = new MyClass().. where t is your class object. If you have not declared,It will always come null.
Or might be you have declared something like this
private Task t; but forgot to add new keyword. Checkout!!!