How to show progress animation without knowing percentage of its completeness?

In a WPF application I need to show user that some process is in progress and one should wait. I don't need to show particular percentage of completeness of this process, moreover, I don't exactly know it.

What is the way to do it? Some special settings of the progress bar or maybe th开发者_JAVA百科ere are other common ways to show animation of this kind?

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Use a ProgressBar and set IsIndeterminate to true. This is the standard way of signaling that progress is occurring, but that it cannot be measured or even estimated.

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Dim aniOpacity As New DoubleAnimation()

aniOpacity.From = 0.1
aniOpacity.To = 1
Dim timeSpanDuration As New TimeSpan(0, 0, lngTakt / 1000)
aniOpacity.Duration = New Duration(timeSpanDuration)

Me.aProgressBar.BeginAnimation(ProgressBar.ValueProperty, aniOpacity)

I not sure, if this is, what you searched. But I don't know, how you want to set a progressbar, if you don't know the state of the progress.

// EDIT: Sorry, now i know what you mean. You can put the code in a loop. If you are finished with your process you stop the loop.