A .Net Framework library, for use in WPF, for controlling the 'Busy' state gracefully. It aims to be simple with one main class that provides a Boolean value for busy which should be used in conjunction with the Xceed Toolkit BusyIndicator or similar control. Mvvm-Light is leveraged for the messaging of processes that aim to set busy state. This class is responsible for managing the busy state which can be problematic if it is just being set in process because different threads can set it prior to other threads completing. This class aims to provide a better solution, namely to have this central static register of running threads, which unregister once complete, then the busy value is only set to true once the register is empty.

For projects using .Net Core &/or .Net Standard use BusyStateManagerStd.

Available to clone and add as a project reference or via NuGet. Install-Package BusyStateManager -Version 1.1.0 or dotnet add package BusyStateManager --version 1.1.0

Or for .Net Standard use BusyStateManagerStd

As this library is aimed at WPF developers, the following is the likely route for instatiation. This uses Mvvm-Light SimpleIoC, however you can of course use your DI of choice or even create an instance without DI.

SimpleIoc.Default.Register<IBusyStateRegistry>(() => 
{
    return new BusyStateRegistry();
});

Then in a view model that inherits from the Mvvm-Light ViewModelBase, at the start and end of long running process add: MessengerInstance.Send(new BusyMessage(true, this)); and MessengerInstance.Send(new BusyMessage(false, this));. For example:

private void OnNavToMatch(MatchWrapper selectedItem)
{
    MessengerInstance.Send(new BusyMessage(true, this));
    try
    {
        // Your long running process
    }
    catch (Exception)
    {
        // Do something about the error
        throw;
    }
    finally
    {
        MessengerInstance.Send(new BusyMessage(false, this));
    }
}

It might be handy to add the above code as a snippet like the one in this project - Busy.snippet.

Add a public property in your view model like this: public IBusyStateRegistry BusyStateManager { get; }, which you would set in the constructor. After that one can add a BusyIndicator, to any view, like the following. First, the Xceed tool ref in the header (if it's not already present):

xmlns:xctk="http://schemas.xceed.com/wpf/xaml/toolkit"

Then somewhere in your view add the control:

<xctk:BusyIndicator IsBusy="{Binding BusyStateManager.IsBusy}">
    <!-- your content here -->
</xctk:BusyIndicator>

Or similar control of your choice.