Program crashes after a few executions

[Thomas Neubauer]

Hello,

i am learning c# and have created now a simple project that just creates 6
random numbers.
My form includes a button and 6 labels for the random numbers. The program
seems to work correct,
however when after a few button clicks the program crashes.

Does anyone know where the reason could be?

--
Kind regards
Thomas Neubauer

using System;
using System.Collecti ons.Generic;
using System.Componen tModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows. Forms;

namespace WindowsApplicat ion1
{
public partial class Form1 : Form
{
public Form1()
{
InitializeCompo nent();
}

private void btZieheLottozah len_Click(objec t sender, EventArgs e)
{
int[] Zahlen = new int[6];
Random Zufallszahl = new Random();
int Doppelte = 0;

do
{
for (int i = 0; i < 6; i++)
{
Zahlen[i] = Zufallszahl.Nex t(1, 64);
}
Array.Sort(Zahl en);
for (int i = 0; i < 5; i++)
if (Zahlen[i] == Zahlen[i + 1])
Doppelte = 1;

} while (Doppelte == 1);

label1.Text = Convert.ToStrin g(Zahlen[0]);
label2.Text = Convert.ToStrin g(Zahlen[1]);
label3.Text = Convert.ToStrin g(Zahlen[2]);
label4.Text = Convert.ToStrin g(Zahlen[3]);
label5.Text = Convert.ToStrin g(Zahlen[4]);
label6.Text = Convert.ToStrin g(Zahlen[5]);
}
}
}

[Jon Skeet [C# MVP]]

Thomas Neubauer <ng****@vol.atw rote:

i am learning c# and have created now a simple project that just creates 6
random numbers.
My form includes a button and 6 labels for the random numbers. The program
seems to work correct,
however when after a few button clicks the program crashes.

Does anyone know where the reason could be?

Well, in what way does it crash? Is there an exception?

--
Jon Skeet - <sk***@pobox.co m>
http://www.pobox.com/~skeet Blog: http://www.msmvps.com/jon.skeet
World class .NET training in the UK: http://iterativetraining.co.uk

[Marc Gravell]

You don't reset Doppelte to 0 at the start of a loop; once you have
hit a duplicate it will loop forever.

Marc

[Peter Duniho]

On 2007-11-20 14:01:12 -0800, "Thomas Neubauer" <ng****@vol.ats aid:

Hello,

i am learning c# and have created now a simple project that just
creates 6 random numbers.
My form includes a button and 6 labels for the random numbers. The
program seems to work correct,
however when after a few button clicks the program crashes.

Does anyone know where the reason could be?

I don't see anything obvious in the code you posted that would cause a crash.

Which is not to say the code is bug-free:

* I wouldn't send an int in to do a bool's job, but that problem
shouldn't cause your program to crash.

* Perhaps more distressingly, you never reset "Doppelte" in your
loop, so if you ever fail to have an array of unique random numbers,
your loop will never exit.

The latter problem would cause your program to stop responding, but a)
I wouldn't call that a "crash", and b) if you interrupt the program in
the debugger you would easily see where the program is stuck, and you
could also just as easily step through the code to see what happens to
the variables and hopefully notice when one isn't behaving as you
expect it to.

The debugger is there to help you. You should use it. :)

Still, you haven't really been very specific in your post. If the
above information doesn't help, what does "crash" mean? Are you
getting an exception? If so, what is the exception? On what line of
code does it occur? What other code is part of your application?

Pete

[=?Utf-8?B?RmFtaWx5IFRyZWUgTWlrZQ==?=]

I love it!

"Peter Duniho" wrote:

On 2007-11-20 14:01:12 -0800, "Thomas Neubauer" <ng****@vol.ats aid:

Hello,

i am learning c# and have created now a simple project that just
creates 6 random numbers.
My form includes a button and 6 labels for the random numbers. The
program seems to work correct,
however when after a few button clicks the program crashes.

Does anyone know where the reason could be?

I don't see anything obvious in the code you posted that would cause a crash.

Which is not to say the code is bug-free:

* I wouldn't send an int in to do a bool's job, but that problem
shouldn't cause your program to crash.

* Perhaps more distressingly, you never reset "Doppelte" in your
loop, so if you ever fail to have an array of unique random numbers,
your loop will never exit.

The latter problem would cause your program to stop responding, but a)
I wouldn't call that a "crash", and b) if you interrupt the program in
the debugger you would easily see where the program is stuck, and you
could also just as easily step through the code to see what happens to
the variables and hopefully notice when one isn't behaving as you
expect it to.

The debugger is there to help you. You should use it. :)

Still, you haven't really been very specific in your post. If the
above information doesn't help, what does "crash" mean? Are you
getting an exception? If so, what is the exception? On what line of
code does it occur? What other code is part of your application?

Pete

[=?Utf-8?B?RmFtaWx5IFRyZWUgTWlrZQ==?=]

Sorry, I never even saw the code, and thought you were making up terms like
Doppelte... Long day at the office...

"Family Tree Mike" wrote:

I love it!

"Peter Duniho" wrote:

On 2007-11-20 14:01:12 -0800, "Thomas Neubauer" <ng****@vol.ats aid:

Hello,
>
i am learning c# and have created now a simple project that just
creates 6 random numbers.
My form includes a button and 6 labels for the random numbers. The
program seems to work correct,
however when after a few button clicks the program crashes.
>
Does anyone know where the reason could be?

I don't see anything obvious in the code you posted that would cause a crash.

Which is not to say the code is bug-free:

* I wouldn't send an int in to do a bool's job, but that problem
shouldn't cause your program to crash.

* Perhaps more distressingly, you never reset "Doppelte" in your
loop, so if you ever fail to have an array of unique random numbers,
your loop will never exit.

The latter problem would cause your program to stop responding, but a)
I wouldn't call that a "crash", and b) if you interrupt the program in
the debugger you would easily see where the program is stuck, and you
could also just as easily step through the code to see what happens to
the variables and hopefully notice when one isn't behaving as you
expect it to.

The debugger is there to help you. You should use it. :)

Still, you haven't really been very specific in your post. If the
above information doesn't help, what does "crash" mean? Are you
getting an exception? If so, what is the exception? On what line of
code does it occur? What other code is part of your application?

Pete

[Peter Duniho]

On 2007-11-20 14:57:00 -0800, Family Tree Mike
<Fa************ @discussions.mi crosoft.comsaid :

Sorry, I never even saw the code, and thought you were making up terms like
Doppelte... Long day at the office...

lol...I was wondering what I'd written that made you so happy.

Still, sounds like something funny to do some day. Maybe next April 1,
we should just all answer questions by sprinkling in made-up words
throughout. :)

[Thomas Neubauer]

Hello all,

thanks to all for your very fast help. I haven't expected such fast help, so
i was really surprised.
I meant that my program doesn't react anymore after a few clicks. Probably
"crash" was the wrong word.
Anyway i solved through setting variable "Doppelte" to 0 on the test of the
last array element.

do
{
for (int i = 0; i < 6; i++)
{
Zahlen[i] = Zufallszahl.Nex t(1, 64);
}
Array.Sort(Zahl en);
for (int i = 0; i < 5; i++)
if (Zahlen[i] == Zahlen[i + 1])
Doppelte = 1;
else
if (Zahlen[i] == 4)
Doppelte = 0;

} while (Doppelte == 1);

--
Kind regards
Thomas Neubauer

[Peter Duniho]

On 2007-11-20 15:23:44 -0800, "Thomas Neubauer" <ng****@vol.ats aid:

Hello all,

thanks to all for your very fast help. I haven't expected such fast
help, so i was really surprised.
I meant that my program doesn't react anymore after a few clicks.
Probably "crash" was the wrong word.
Anyway i solved through setting variable "Doppelte" to 0 on the test of
the last array element.

Yuck!

Why not just set it in the first line of the do/while loop? There's
not even a need to initialize in the declaration if you do that.

I would still change it to a bool, in any case.

Pete

[Marc Gravell]

Ditto that "Yuck!"

Actually you could make the whole thing a lot simpler... it looks like
you just want 6 sorted random numbers in a range with no duplicates...
so how about:

Random rand = new Random();
List<intfound = new List<int>();
while (found.Count < 6) {
int newNumber;
while (found.Contains (newNumber = rand.Next(1, 64)))
{ }
found.Add(newNu mber);
}
found.Sort();
int[] array = found.ToArray() ; // if you *need* an array

One advantage here is that it doesn't throw away everything just
because of a collision - it just dumps the duplicated value; this
might be significant if the numbers get larger. But more importantly
there are no complicated exit variables to set/reset - just "have we
got everything we need yet?"

Marc