Problem on modal dialog

  • Thread starter Thread starter babylon
  • Start date Start date
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babylon

I have a Form form1
i created another thread in from1
the thread will listen for a network packet from a server
if the thread receive the packet
i would like to open a modal dialog that will block all the user input to
the form1

i tried the following:

public class Form1 : System.Windows.Forms.Form
{
static Form1 p = null;
public Form1()
{
p = this;
InitializeComponent();
Thread t = new Thread(new ThreadStart(thread));
t.Start();
}
public static void thread()
{
Thread.Sleep(1000); // wait until a network packet comes....
Form c = new Form();
c.ShowDialog(p);
}
}

....it didn't work....the user still able to play with form1...

any idea?
thx!
 
Hi,

The multithreading mantra for Windows Forms is: "The Control.Invoke() is
king. Always use Control.Invoke when talking to a form from another thread,
unless Control.IsInvokeRequired tells you otherwise".

So what you need is this:

1. Create a public method in the Form class that would display the dialog
2. When the working thread receives a packet, call this public method
through form's Invoke method (remember Form is inherited from Control).
3. DO NOT call ShowDialog directly from the working thread. It may not only
show a non-blocking dialog, but also crash the whole application.
 
babylon said:
I have a Form form1
i created another thread in from1
the thread will listen for a network packet from a server
if the thread receive the packet
i would like to open a modal dialog that will block all the user input to
the form1
Click to expand...

The form must be created in the main GUI thread. You can do this by
invoking a public procedure in the GUI thread.

You will find more information on multithreading + Windows Forms in this
article:

<http://www.devx.com/dotnet/Article/11358>
 
thank you very much!!!
it really works!!


Dmitriy Lapshin said:
Hi,

The multithreading mantra for Windows Forms is: "The Control.Invoke() is
king. Always use Control.Invoke when talking to a form from another thread,
unless Control.IsInvokeRequired tells you otherwise".

So what you need is this:

1. Create a public method in the Form class that would display the dialog
2. When the working thread receives a packet, call this public method
through form's Invoke method (remember Form is inherited from Control).
3. DO NOT call ShowDialog directly from the working thread. It may not only
show a non-blocking dialog, but also crash the whole application.

--
Dmitriy Lapshin [C# / .NET MVP]
X-Unity Test Studio
http://x-unity.miik.com.ua/teststudio.aspx
Bring the power of unit testing to VS .NET IDE

babylon said:
I have a Form form1
i created another thread in from1
the thread will listen for a network packet from a server
if the thread receive the packet
i would like to open a modal dialog that will block all the user input to
the form1

i tried the following:

public class Form1 : System.Windows.Forms.Form
{
static Form1 p = null;
public Form1()
{
p = this;
InitializeComponent();
Thread t = new Thread(new ThreadStart(thread));
t.Start();
}
public static void thread()
{
Thread.Sleep(1000); // wait until a network packet comes....
Form c = new Form();
c.ShowDialog(p);
}
}

...it didn't work....the user still able to play with form1...

any idea?
thx!
Click to expand...
Click to expand...
 
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