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Solved
My Form is not responding
Posted on 2009-05-17
Hi,
When I run my code, and click a button, the msgs are dispalyed in the rich textbox.
When I tried to move the scroll bar on the richtextbox while the process was still running, the whole form became "not responding."
What should I do to use my scroll bar to see all the displays while the process is still running?
namespace WindowsFormsApplication1
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
this.richTextBox1.Update()
this.richTextBox1.Clear();
for (int i = 0; i < 3; i++)
{
AddHi(i);
Thread.Sleep(10000);
AddBye(i);
}
this.button1.Enabled = true;
}
public delegate void GreetingDelegate(string str);
public void AddGreeting(string str)
{
if (this.richTextBox1.InvokeR
{
this.richTextBox1.Invoke(n
return;
}
else
{
this.richTextBox1.AppendTe
this.richTextBox1.Refresh(
}
}
public void AddHi(int i)
{
try
{
AddGreeting("Hi " + i.ToString() + "\n");
}
catch (Exception e)
{
e.Message.ToString();
}
}
public void AddBye(int i)
{
try
{
AddGreeting("Bye " + i.ToString() + "\n");
}
catch (Exception e)
{
e.Message.ToString();
}
}
}
}
When I run my code, and click a button, the msgs are dispalyed in the rich textbox.
When I tried to move the scroll bar on the richtextbox while the process was still running, the whole form became "not responding."
What should I do to use my scroll bar to see all the displays while the process is still running?
namespace WindowsFormsApplication1
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
this.richTextBox1.Update()
this.richTextBox1.Clear();
for (int i = 0; i < 3; i++)
{
AddHi(i);
Thread.Sleep(10000);
AddBye(i);
}
this.button1.Enabled = true;
}
public delegate void GreetingDelegate(string str);
public void AddGreeting(string str)
{
if (this.richTextBox1.InvokeR
{
this.richTextBox1.Invoke(n
return;
}
else
{
this.richTextBox1.AppendTe
this.richTextBox1.Refresh(
}
}
public void AddHi(int i)
{
try
{
AddGreeting("Hi " + i.ToString() + "\n");
}
catch (Exception e)
{
e.Message.ToString();
}
}
public void AddBye(int i)
{
try
{
AddGreeting("Bye " + i.ToString() + "\n");
}
catch (Exception e)
{
e.Message.ToString();
}
}
}
}
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14 Comments
use Application.doEvents.
http://msdn.microsoft.com/en-us/library/system.windows.forms.application.doevents.aspx
http://msdn.microsoft.com/en-us/library/system.windows.forms.application.doevents.aspx
My form still gets 'not responding' with Application.DoEvent(). Is put that in the for loop from my code.
Let me explain you a little about threads.
The GUI runs on the main thread of the application. Once you do an infinite loop or sleep (in your cause for 10 seconds), the main thread become locked and the GUI doesn't redraw itself.
This is why your form is not responding.
In my opinion Any action that takes 500 Milliseconds should be performed on another thread.
Your form should start a new thread that will do the long process job, while in the meanwhile the parts in the form that need to be disabled get disabled.
When the thread finished doing what it supposed to do then it re-enables what it needs in the form and do whatever action in needs to do in the form, all of that while considering thread safety and preventing cross-thread access to the GUI
(You will need to use delegates to do this.Invoke when this.InvokeRequired is true)
The GUI runs on the main thread of the application. Once you do an infinite loop or sleep (in your cause for 10 seconds), the main thread become locked and the GUI doesn't redraw itself.
This is why your form is not responding.
In my opinion Any action that takes 500 Milliseconds should be performed on another thread.
Your form should start a new thread that will do the long process job, while in the meanwhile the parts in the form that need to be disabled get disabled.
When the thread finished doing what it supposed to do then it re-enables what it needs in the form and do whatever action in needs to do in the form, all of that while considering thread safety and preventing cross-thread access to the GUI
(You will need to use delegates to do this.Invoke when this.InvokeRequired is true)
saragani has it. But since I had coded this change for you, here it is:
David
David
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Threading;
namespace RichTextDelay
{
public partial class Form1 : Form
{
Thread backgroundThread = null;
public Form1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
this.button1.Enabled = false;
this.richTextBox1.Update();
this.richTextBox1.Clear();
backgroundThread = new Thread(delegate() { DoStuff(); });
backgroundThread.Start();
}
private void DoStuff()
{
for (int i = 0; i < 3; i++)
{
AddHi(i);
Thread.Sleep(10000);
AddBye(i);
}
this.Invoke((MethodInvoker) delegate { this.button1.Enabled = true; });
}
public delegate void GreetingDelegate(string str);
public void AddGreeting(string str)
{
if (this.richTextBox1.InvokeRequired)
{
this.richTextBox1.Invoke(new GreetingDelegate(AddGreeting), str);
return;
}
else
{
this.richTextBox1.AppendText(str);
this.richTextBox1.Refresh();
}
}
public void AddHi(int i)
{
try
{
AddGreeting("Hi " + i.ToString() + "\n");
}
catch (Exception e)
{
e.Message.ToString();
}
}
public void AddBye(int i)
{
try
{
AddGreeting("Bye " + i.ToString() + "\n");
}
catch (Exception e)
{
e.Message.ToString();
}
}
private void Form1_FormClosing(object sender, FormClosingEventArgs e)
{
if (backgroundThread != null)
{
backgroundThread.Abort();
backgroundThread = null;
}
}
}
}
If you want to "simulate" long "work" then try something like this:
Delay(10); // delay for ten seconds
The method:
Delay(10); // delay for ten seconds
The method:
private void Delay(int DelayInSeconds)
{
TimeSpan ts;
DateTime targetTime = DateTime.Now.AddSeconds(DelayInSeconds);
do
{
ts = targetTime.Subtract(DateTime.Now);
Application.DoEvents(); // keep app responsive
System.Threading.Thread.Sleep(50); // reduce CPU usage
}
while (ts.TotalSeconds > 0);
}
I see your point saragani. I guess you mean I need to use the method(in this case, Thread.Sleep(10000)) with a new thread between AddHi(i) and AddBye(i). I guess I also need to make AddBye(i) wait until Thread.Sleep(10000) is all done.
Could you show me some example or code? I checked msdn, but still confusing how to apply cross-thread solution in my case.
Could you show me some example or code? I checked msdn, but still confusing how to apply cross-thread solution in my case.
You can modify your code like this
public partial class Form1 : Form
{
bool wait = true;
public Form1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
this.button1.Enabled = false;
this.richTextBox1.Update();
this.richTextBox1.Clear();
for (int i = 0; i < 3; i++)
{
AddHi(i);
Thread waitThread = new Thread(new ThreadStart(WaitMethod));
waitThread.Start();
while (wait)
{
Application.DoEvents();
}
AddBye(i);
}
this.button1.Enabled = true;
}
public void WaitMethod()
{
Thread.Sleep(10000);
wait = false;
}
public delegate void GreetingDelegate(string str);
public void AddGreeting(string str)
{
if (this.richTextBox1.InvokeRequired)
{
this.richTextBox1.Invoke(new GreetingDelegate(AddGreeting), str);
return;
}
else
{
this.richTextBox1.AppendText(str);
this.richTextBox1.Refresh();
}
}
public void AddHi(int i)
{
try
{
AddGreeting("Hi " + i.ToString() + "\n");
}
catch (Exception e)
{
e.Message.ToString();
}
}
public void AddBye(int i)
{
try
{
AddGreeting("Bye " + i.ToString() + "\n");
}
catch (Exception e)
{
e.Message.ToString();
}
}
}
Wow..it's really cool. Thanks!
I have a qucik question from your code, anyoneis.
Could you explain 'this.Invoke((MethodInvoke
I have a qucik question from your code, anyoneis.
Could you explain 'this.Invoke((MethodInvoke
He is using something called Anonymous Methods. It is a cool thing that Vb.Net doesn't support.
This is a good example of updating the GUI from another thread:
http://www.codeproject.com/KB/cs/ModelViewPresenterWithDI.aspx
This is where I first saw the cool usage of anonymous methods (before that I had to write my own delegates, and lots of them, for doing this.invoke).
Just search for UpdateUI in that article.
This is a good example of updating the GUI from another thread:
http://www.codeproject.com/KB/cs/ModelViewPresenterWithDI.aspx
This is where I first saw the cool usage of anonymous methods (before that I had to write my own delegates, and lots of them, for doing this.invoke).
Just search for UpdateUI in that article.
It is just a shorthand for the same thing you did with GreetingDelegate - it reduces all of the delegate declarations and little event functions that you have to write.
I like this article: http://www.yoda.arachsys.c
where he gives this example:
using System;
delegate void SomeAction();
class Test
{
static void Main(string[] args)
{
SomeAction instance = delegate { Console.WriteLine(args[0])
}
}
The reason the above works is becuase the compiler knows what kind of delegate it needs (SomeAction.). In my cvase, it did not, so I had to tell it with a cast. I hjave seen others use "Action" as the delegate type in this situation.
this.Invoke((MethodInvoker
David
I like this article: http://www.yoda.arachsys.c
where he gives this example:
using System;
delegate void SomeAction();
class Test
{
static void Main(string[] args)
{
SomeAction instance = delegate { Console.WriteLine(args[0])
}
}
The reason the above works is becuase the compiler knows what kind of delegate it needs (SomeAction.). In my cvase, it did not, so I had to tell it with a cast. I hjave seen others use "Action" as the delegate type in this situation.
this.Invoke((MethodInvoker
David
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