Wait for button click while reading or during a loop

Question

I am creating a time clock program. Our office staff would like to be able to send messages to specific employees when they clock in. The issue I have is if there are multiple messages to display, it loops through to the last one.

while(reader.Read()
{
     richtextbox.Text = reader["Message"].ToString();
     //need to pause here and wait for them to press the acknowledge button
{

Is there a way to wait or pause until the press the acknowledge button.

Any help is appreciated.

ps. I have tried using

public static class Utils
{
    public static Task WhenClicked(this Control target)
    {
        var tcs = new TaskCompletionSource<object>();
        EventHandler onClick = null;
        onClick = (sender, e) =>
        {
            target.Click -= onClick;
            tcs.TrySetResult(null);
        };
        target.Click += onClick;
        return tcs.Task;
    }
}

from this thread Wait until a click event has been fired C# but It did the same thing and blew past the button and showed the last message again.

Please show your attempted usage of `WhenClicked`. That solution should have worked — BradleyDotNET, Dec 14 '18 at 18:03
I am not exactly sure what you want me to show you. while(reader.Read() { richtextbox.Text = reader["Message"].ToString(); WhenClicked(button1); { this is what I put in the code. But like I said it skipped over all the other messages and just showed the last one. Is there anything specific you need me to show? I am very new at this and appreciate any help. The work around I have come up with for now is just to show a message box with the message being shown in the Message Box. It works but just annoying I cannot figure out how to do it the other way — Brett Byrd, Dec 14 '18 at 18:59

score 1 · Accepted Answer · answered Dec 14 '18 at 22:45

I would approach the problem like this. Make your reader load all of the messages into a collection like a Queue (which is a first-in-first-out collection, ideal for what you are trying to do.) After the loop, if there are any messages, display the first one. Wire up the click event to a similar block of code that will display the next message (if any more exist) each time the button is clicked. The code would look like this:

Queue<string> EmployeeMessages = new Queue<string>();
private void OnLogin()
{
    var reader = GetReader();

    while (reader.Read())
    {
        EmployeeMessages.Enqueue(reader["Message"].ToString());
    }

    if (EmployeeMessages.Count > 0)
    {
        label1.Text = EmployeeMessages.Dequeue();
    }
}


private void button1_Click(object sender, EventArgs e)
{
    if (EmployeeMessages.Count > 0)
    {
        label1.Text = EmployeeMessages.Dequeue();
    }
}

This was it! Works perfect! Not enough reputation for it to show as the marked answer but this is most definitely what I was looking for! Thanks for your Help! — Brett Byrd, Dec 17 '18 at 13:55

Wait for button click while reading or during a loop

1 Answers1