C# argument out of range was unhandled due to the SelectedIndex

haan jae

'Argument out of range was unhandled' error occur when button is clicked due to no number or no such index number of client connected is selected. Error show to this code:

workerSocket = (Socket)m_workerSocketList[comboBox1.SelectedIndex];

i want to give a message box say 'Please select a correct number'. what should be coded to handle this error?

here is the code:

void indmsgbtn_Click(object sender, EventArgs e)
{
string msg = richtxtindmsg.Text;
msg = "Private Admin Message: " + msg + "\n";
byte[] byData = System.Text.Encoding.ASCII.GetBytes(msg);
Socket workerSocket = null;
workerSocket = (Socket)m_workerSocketList[comboBox1.SelectedIndex];

if (workerSocket != null)
{
if (workerSocket.Connected)
{
workerSocket.Send(byData);
}

}

}

7 Replies

Know the answer? Post it — somebody with the same question will find it here.

Vulpes15y ago
Accepted answer
Try this:

void indmsgbtn_Click(object sender, EventArgs e)
{
string msg = richtxtindmsg.Text;
msg = "Private Admin Message: " + msg + "\n";
byte[] byData = System.Text.Encoding.ASCII.GetBytes(msg);
Socket workerSocket = null;

try
{
workerSocket = (Socket)m_workerSocketList[comboBox1.SelectedIndex];
}
catch(ArgumentOutOfRangeException)
{
MessageBox.Show("Please select a correct number");
return;
}

if (workerSocket != null)
{
if (workerSocket.Connected)
{
workerSocket.Send(byData);
}
}
}
0
Sam Hobbs14y ago
I think the answer here is essentially the same as in Send message to Specific Client by selecting number in comboBox.

There is an easier way to do this. You can make a class that represents connections; you probably have done that already. Then you can add objects of that class as combobox items. Then all you have to do is to cast the sected combobox item to the connection object. Look at the articles in this web site for details about how to do that; I assume it is described very well in articles here. If not then let us know you need help with it.
0
haan jae14y ago
ya, maybe will do that, or i will just let the user to key in the index number manually.

anyway, thanks again for helping me. :)
0
Vulpes14y ago
Why don't you just remove disconnected sockets from both the combobox and the list. The user won't then be able to select them.
0
haan jae14y ago
thanks for the reply.

no, the code doesn't solve as well. i try putting another catch after catch for ArgumentOutOfRangeException, but obviously doesn't work as well.
catch
{
workerSocket = null;
MessageBox.Show("Please select number.");
}

but the index number of connected client will keep adding even through client disconnect and reconnect, until the server system restart, then only the index number will start with 1 again.
0
Vulpes14y ago
Judging by the name, I'd guess that m_workerSocketList is a List.

Unless you've removed the disconnected socket from the list, then it will still be there at index 3 and so the MessageBox won't show.

To show a suitable message if the selected socket is disconnected, I'd suggest the following modification:

void indmsgbtn_Click(object sender, EventArgs e)
{
string msg = richtxtindmsg.Text;
msg = "Private Admin Message: " + msg + "\n";
byte[] byData = System.Text.Encoding.ASCII.GetBytes(msg);
Socket workerSocket = null;

try
{
workerSocket = (Socket)m_workerSocketList[comboBox1.SelectedIndex];
}
catch(ArgumentOutOfRangeException)
{
MessageBox.Show("Please select a correct number");
return;
}

if (workerSocket != null)
{
if (workerSocket.Connected)
{
workerSocket.Send(byData);
}
else
{
MessageBox.Show("Please select a connected socket"); // or whatever you want to say
}
}
}
0
haan jae14y ago
thank you so much for helping me, you save my day :)
but i realize there is one problem, the message box will not show again if select the index number that match the connected client who already disconnected. like if client no 3 disconnect, i tried to select number 3 in comboBox to send message, see whether the message box will show out or not, but it didnt show. Any idea why this happen??

Anyway, thanks again for the help.
0