|There are two different versions of anything called a "Progress Bar".
The first is one where the progress bar goes from 0% to 100%. In order for this to work, your code has to know where the stopping point is in order to generate a value that can go from 0 to 100. It also has to update the progress bar (noone cares what form it's on!) every once in a while with the current value of the progress.
The second is a progress bar that doesn't, well, progress. What that means is that your code doesn't need to know how long a process will take or show any actual progress. The progress bar just displays a moving image that show something is going on. It has no idea how long the process will take or how long it has yet to go.
So, which is it for you?