代码滞后于UI，但我不清楚如何在需要输入的任务上使用后台工作程序

Question

I am pinging about 10-15 ips on my network (employee phones) to put up a display if they are in the office our out of the office

I have a timer that has a 5000ms tick that kicks of a ping on all the ip's

I've tried to do a background worker or a tread but the problem is that they seem to either 1) not want to take passed paramiters or 2) do not have access to update form controls

 private void Check()
    {

        foreach (StatusBox sb in flowLayoutPanel1.Controls)
        {

            Ping pingSender = new Ping();

            PingReply reply = pingSender.Send(sb.IPaddress, 10);

            if (reply.Status == IPStatus.Success)  //device found update last seen
            {
                sb.Color = Color.Green;
                sb.lastseen = DateTime.Now.ToLongTimeString();
                sb.lastseenDate = DateTime.Now;
            }
            else
            {
                if (sb.lastseenDate != Convert.ToDateTime("1/1/0001 12:00:00 AM"))  //no date means device has not been found yet
                {
                    if (sb.lastseenDate.AddMinutes(10) < DateTime.Now)
                    {
                        sb.Color = Color.Yellow;
                    }
                    else if (sb.lastseenDate.AddHours(1) < DateTime.Now)
                    {                            
                        sb.Color = Color.LightGray;
                    }
                }                 
            }      
        }

Answer 1

Accessing controls on a form is not thread safe, to change properties to a control you need to access the control from the thread the window form is running... For example here a function to change the color of your Status box

private void SetColor(StatusBox sb, Color col)
{
   if (sb.InvokeRequired)
{   
    SetTextCallback d = new SetTextCallback(SetColor);
    this.Invoke(d, new object[] { col});
}
else
{
    sb.Color = col;
}
 }

You can find more examples and explainations on this page : https://msdn.microsoft.com/en-us/library/ms171728(v=vs.110).aspx