C# Wait until condition is true

Question

I am trying to write a code that executes when a condition is met. Currently, I am using while...loop, which I know is not very efficient. I am also looking at AutoResetEven

Answer 1

Ended up writing this today and seems to be ok. Your usage could be:

await TaskEx.WaitUntil(isExcelInteractive);

code (including the inverse operation)

public static class TaskEx
{
    /// 

    /// Blocks while condition is true or timeout occurs.
    /// 
    /// The condition that will perpetuate the block.
    /// The frequency at which the condition will be check, in milliseconds.
    /// Timeout in milliseconds.
    /// 
    /// 
    public static async Task WaitWhile(Func condition, int frequency = 25, int timeout = -1)
    {
        var waitTask = Task.Run(async () =>
        {
            while (condition()) await Task.Delay(frequency);
        });

        if(waitTask != await Task.WhenAny(waitTask, Task.Delay(timeout)))
            throw new TimeoutException();
    }

    /// 

    /// Blocks until condition is true or timeout occurs.
    /// 
    /// The break condition.
    /// The frequency at which the condition will be checked.
    /// The timeout in milliseconds.
    /// 
    public static async Task WaitUntil(Func condition, int frequency = 25, int timeout = -1)
    {
        var waitTask = Task.Run(async () =>
        {
            while (!condition()) await Task.Delay(frequency);
        });

        if (waitTask != await Task.WhenAny(waitTask, 
                Task.Delay(timeout))) 
            throw new TimeoutException();
    }
}

Example usage: https://dotnetfiddle.net/Vy8GbV