C# - Displaying a progressbar while executing an SQL Query.

[yoavyoavyoav]

Hi ,

I would like a progress bar to be displayed while running an sql query. the progress bar doesn't have to move according to the query pace - I just want it to move back and forth while the query is executing , and to disappear when the query is completed.

My problem is that the progress bar does not appear when the query is running (I'm using the data adapter fill method in order to run my queries). What can I do ?

Thanks in advance.

[iqbalali]

am doing the same thing but am stuck with the threads join?? will you help about it?

[broger]

You don't really need to join back up with the main thread, nor even wait for the spawned thread to finish. First, you'll need these methods:

private delegate void SetControlPropertyThreadSafeDelegate(Control control, string propertyName, object propertyValue);
        public static void SetControlPropertyThreadSafe(Control control, string propertyName, object propertyValue)
        {
            if (control.InvokeRequired)
            {
                control.Invoke(new SetControlPropertyThreadSafeDelegate(SetControlPropertyThreadSafe),
                    new object[] { control, propertyName, propertyValue });
            }
            else
            {
                control.GetType().InvokeMember(propertyName, BindingFlags.SetProperty, null, control, new object[] { propertyValue });
            }
        }
        private void StartProgressBar(ProgressBar pb)
        {
            SetControlPropertyThreadSafe(pb, "Visible", true);
            SetControlPropertyThreadSafe(pb, "Style", ProgressBarStyle.Marquee);
            SetControlPropertyThreadSafe(pb, "MarqueeAnimationSpeed", 100);
        }
        private void StopProgressBar(ProgressBar pb)
        {
            SetControlPropertyThreadSafe(pb, "Style", ProgressBarStyle.Blocks);
            SetControlPropertyThreadSafe(pb, "MarqueeAnimationSpeed", 0);
            SetControlPropertyThreadSafe(pb, "Visible", false);
        }

Using this, you can set the progress bar to either be running or stopped from within your thread. Use these two calls within the threaded method to start/stop:

StartProgressBa r(ProgressBar);
StopProgressBar (ProgressBar);

Generally, between those two, I do some processing, and then call Invoke(new MethodInvoker(< Method>)) to save the results of the thread to the main form. Essentially, it works by a) starting the thread, b) gathering data/perform some sort of task, c) invoking the method which uses the data that you've saved from your thread (which is threadsafe, due to Invoke()), d) finishing it up by stopping the progress bar

Hope this helps

[Sfreak]

Try using

Application.DoEvents();

to free your UI while you run those threads.