Hi I'm trying to create a simple program that pings everything on our network over a minute and changes the UI based on the results of that ping.

I have a background worker that sets the variables and pings the appropriate IP address.

This is contained within a while loop that waits for ping to be true. Within this loop is a For Loop that takes in user input to ping that specific amount of times.

The for loop worked fine, and in debugging I can see i incrementing as usual.

I have a break point on the for loop line itself as well as the curly brace after it. If the user input is 2, it will run through twice, then the i variable explicitly changes to 0 and then reaches the if() statement

This was all working perfectly until I added some code within the nested for loops. But I cannot see anything that would be changing i

Here are some pictures showing what I mean

The loop has ran twice, and as such i is equal to 2. I then continue once more to the curly brace and i is now 0 and so doesn't break the loops.

Here's the entire method: ...

    private async void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
    {
        // variables
        bool ping = false;
        int i;
        // Create ping objects
        // TODO read these variables in from the config screen and create a class to handle it (populatePing)
        // Ping 2
        ping0.SetFqdn("##");
        ping0.SetIpAddress("##");
        ping0.SetFriendlyName("##");
        // Ping 1
        ping1.SetFqdn("##");
        ping1.SetIpAddress("##");
        ping1.SetFriendlyName("##");

        // Create file (needs updating to utilise wildcards)
        using StreamWriter file = new("C:/Users/##/AppData/Roaming/log.txt", append: true);

        try
        {
            // Create background worker 
            BackgroundWorker worker = (BackgroundWorker)sender;
            while (!ping)
            {
                // Write to log file
                await file.WriteAsync("Starting job...\n");
                await file.WriteAsync("Requested amount of pings: "   count   "\n");
                // Create date object for logs
                DateTime localDate = DateTime.Now;

                for (i = 0; i < count; i  )
                {
                    // if count has reached the user input limit, break the loop
                    if (i == count)
                    {
                        ping = true;
                    }

                    // Create ping objects
                    System.Net.NetworkInformation.Ping pinger = new System.Net.NetworkInformation.Ping();
                    PingReply ip0_ping, ip1_ping;

                    try
                    {

                        if(!ping0.Equals(null))
                        {
                            try
                            {
                                // Send ping to specified IP address
                                ip0_ping = pinger.Send(ping0.GetIpAddress());
                                // Write log file
                                await file.WriteLineAsync(localDate.TimeOfDay   " |  Friendly Name"   ping0.GetFriendlyName()   ": Ping: "   ip0_ping.Address   " status: "   ip0_ping.Status   ". time: "   ip0_ping.RoundtripTime   "ms");
                                
                                // Successful ping has been sent
                                if(ip0_ping.Status.ToString().Contains("Success"))
                                {
                                    ping0.SetSuccessfulPings(1);
                                } else // Unsuccessful ping has been sent
                                {
                                    ping0.SetFailedPings(1);
                                }
                            }
                            catch(Exception d) 
                            {
                                Debug.WriteLine(d.ToString());
                            }

                        } else
                        {
                            Debug.WriteLine("ERROR: ping0 is not being populated correctly");
                        }

                        if(!ping1.Equals(null))
                        {
                            try
                            {
                                // Send ping to specified IP address
                                ip1_ping = pinger.Send(ping1.GetIpAddress());
                                // Write log file
                                await file.WriteLineAsync(localDate.TimeOfDay   " |  Friendly Name"   ping1.GetFriendlyName()   ": Ping: "   ip1_ping.Address   " status: "   ip1_ping.Status   ". time: "   ip1_ping.RoundtripTime   "ms");

                                // Successful ping has been sent
                                if (ip1_ping.Status.ToString().Contains("Success"))
                                {
                                    ping1.SetSuccessfulPings(1);
                                }
                                else // Unsuccessful ping has been sent
                                {
                                    ping1.SetFailedPings(1);
                                }

                            }
                            catch(Exception d)
                            {
                                Debug.WriteLine(d.ToString());
                            }
                        }


                        // wait one second
                        wait(1000);
                    }
                    catch (Exception b)
                    {
                        Debug.WriteLine(b.ToString());
                    }
                }
            }
        } catch (Exception a)
        {
            Debug.WriteLine(a.ToString());
        }
    }

...

Sorry if this is really obvious but I'm really stumped

CodePudding user response：

The method will not exit since the for loop is not entered if i == count since the condition section of your for loop evaluates if i < count.

See the following link under the for loop section: https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/statements/iteration-statements

The condition section that determines if the next iteration in the loop should be executed. If it evaluates to true or is not present, the next iteration is executed; otherwise, the loop is exited. The condition section must be a Boolean expression.

and also

The iterator section that defines what happens after each execution of the body of the loop.