private void Send_Click(object sender, EventArgs e)
{
// Set button state to false
SendBtn.Enabled = false;
// Create a new equation object from the given data
Equations equation = new Equations(Convert.ToInt32(textBoxFnumber.Text),
Convert.ToInt32(textBoxSnumber.Text), comboBoxOperators.Text, Convert.ToInt32(textBoxAnumber.Text), false);
try
{
// Serialize the object into a json string and send the data to the client
string json = JsonConvert.SerializeObject(equation);
var sendData = Encoding.ASCII.GetBytes(json);
clientSocket.BeginSend(sendData, 0, sendData.Length, SocketFlags.None, SendCallback, null);
}
catch (NullReferenceException)
{
MessageBox.Show("Unable to send message, there is no client connected.", Application.ProductName, MessageBoxButtons.OK, MessageBoxIcon.Warning);
SendBtn.Enabled = true;
}
// Add equation to list to be displayed
equations.Insert(0, equation);
RefreshResultDatagrid();
}
private void ReceiveCallback(IAsyncResult AR)
{
try
{
// Socket exception will raise here when client closes
int received = clientSocket.EndReceive(AR);
if (received == 0)
{
return;
}
// The received data is deserialized in the EquationProperties.
string message = Encoding.ASCII.GetString(buffer);
// Any excess characters are stipped of the end
int index = message.IndexOf("}");
message = message.Substring(0, index + 1);
// Deserialize the json string into the equation object
equation = JsonConvert.DeserializeObject <Equations>(message);
// Create new node and add to nodelist
Invoke((Action) delegate
{
LinkListNode node = new LinkListNode(equation);
equationNodeList.AddEquationNode(node);
});
//add the node to the binary tree
if (tree.root == null)
{
//if tree is emtpy, set the node as the root
tree.root = new BinaryTreeNode(equation);
}
else
{
//add the node to the bindary tree
tree.Add(equation);
}
Invoke((Action) delegate
{
rtbAsked.Clear();
//the default print order for the binary tree is in-order
//rtbAsked.Text = BinaryTree.PrintInOrder(tree);
SendBtn.Enabled = true;
});
// Check if answer is incorrect
if (equation.IsCorrect == false)
{
Invoke((Action) delegate
{
if (equation.IsCorrect == false)
{
rtbWrong.Text = InstructorController.PrintLinkList(equationNodeList);
}
});
}
// Start receiving data again.
clientSocket.BeginReceive(buffer, 0, buffer.Length, SocketFlags.None, ReceiveCallback, null);
}
// Avoid catching all exceptions handling in cases like these.
catch (SocketException ex)
{
ShowErrorDialog(ex.Message);
Invoke((Action) delegate
{
//lbl_clientCount.Text = "No connected clients";
});
}
catch (ObjectDisposedException ex)
{
ShowErrorDialog(ex.Message);
}
}
