C#

private Object _lockObject = new Object();
.
.
.
lock(_lockObject)
{
    ...
}

public class TcpServer {

        private Object _lockObject = new Object()                <-- HERE

        // ConnectionList should be private because 
        // if it's public there is nothing to stop people
        // from outside the class modifying it. You 
        // should instead expose public accessors that 
        // either provide a full deep copy of the list, 
        // or just return specific items from the list.
        private List ConnectionList { get; }

        public void start () { }

        public void stop () { }

        private void client_Connected ( TcpClient client ) {
            lock(_lockObject)                                    <-- HERE
            {
                ConnectionList.Add( client );
            }
        }

        private void client_Disconnected ( TcpClient client ) {
            lock(_lockObject)                                    <-- HERE
            {
                ConnectionList.Remove( client );
            }
        }
    }

MarkPhB wrote:

I understand you when you say... lock object should really be private ...but in a development, you should know what you are doing.
So, thats why it is not really necessary, i think [Smile]

Simon Stevens wrote:

nasty horrible programmers who don't like you might write a program that reflects on your assembly, and takes a lock on your public lock object

Simon Stevens wrote:

Public lock objects are bad practice

MarkPhB wrote:

Well in that case you have no chance. If someone uses reflection then there is no way to protect it.
With Reflection someone can do everything, unimportant whether the lockObject is private or public. [Wink]

MarkPhB wrote:

OK, but how shall i lock the ConnectionList for an external enumeration ?
...or shall i copy the entire ConnectionList befor i enumerate it ? [Sniff]

Laji59 wrote:

help me immediately please

public Form1()
        {
            InitializeComponent();

            printDocument1.PrintPage += printDocument1_PrintPage;
        }

        private void btnPrint_Click(object sender, EventArgs e)
        {
            using (PrintDialog pd = new PrintDialog())
            {
                if (pd.ShowDialog() == DialogResult.OK)
                {
                    printDocument1.PrinterSettings = pd.PrinterSettings;

                    printDocument1.Print();
                }
            }
        }

        void printDocument1_PrintPage(object sender, System.Drawing.Printing.PrintPageEventArgs e)
        {
            Font objFont = new Font("Tahoma", 8.5F);
            float fTopMargin = e.MarginBounds.Top;
            float fLeftMargin = 50;
            float fRightMargin = e.MarginBounds.Right - 150;


            string Name = String.Concat("Name: ", txtName.Text);
            string PhoneNumber = String.Concat("Phone Number: ", txtPhoneNum.Text);
            string Email = String.Concat("Email Address: ", txtEmail.Text);
            string DateOfBirth = String.Concat("Date Of Birth: ", txtDateOfBirth.Text);

            e.Graphics.DrawString(Name, objFont, Brushes.Black, fLeftMargin, fTopMargin);
            e.Graphics.DrawString(PhoneNumber, objFont, Brushes.Black, fRightMargin - PhoneNumber.Length, fTopMargin);

            fTopMargin += objFont.GetHeight() * 2; // Skip 2 lines

            e.Graphics.DrawString(Email, objFont, Brushes.Black, fLeftMargin, fTopMargin);

            fTopMargin += objFont.GetHeight(); //skip one more line

            e.Graphics.DrawString(DateOfBirth, objFont, Brushes.Black, fLeftMargin, fTopMargin);



            objFont.Dispose();
            e.HasMorePages = false;
        }