Question

i am using multiple threads to do some processes and i want to display the total progress in a progressbar so How can i do the ProgressBar1.Increment(1) in a safe way?

Public Sub thread1process()
    For i = 0 To t1.Rows.Count - 1
        t1.Rows(i)("cname") = "Thread1"
        t1.Rows(i)("PD") = i
        t1.Rows(i)("PDP") = i
        t1.Rows(i)("TPD") = i
        t1.Rows(i)("TPDP") = i
        ProgressBar1.Increment(1)
    Next
End Sub

Public Sub thread2process()
    For i = 0 To t2.Rows.Count - 1
        t2.Rows(i)("cname") = "Thread2"
        t2.Rows(i)("PD") = i
        t2.Rows(i)("PDP") = i
        t2.Rows(i)("TPD") = i
        t2.Rows(i)("TPDP") = i
        ProgressBar1.Increment(1)
    Next
End Sub

also how would i increase a public variable from multiple threads in the same time?

Answer 1

How can i do the ProgressBar1.Increment(1) in a safe way?

You could use the Invoke method on the Form in order to marshal the call on the main UI thread.

also how would i increase a public variable from multiple threads in the same time?

Use the Interlocked.Increment method.