stop current thread until input is received from another window wpf C#

I want to stop other Threads until the user provides input in this window... giving code that I have as such:

if (!File.Exists(@"DiscoveryConfig.bin"))
{
    Application.Current.Dispatcher.Invoke((showRangeInputWindow)delegate()
    {
        new WinSubnetRangeInput().Show();
    }, null);
}

Lets say the following code do a Ping scan of network nodes but first it opens a window to take a range. But, how to stop scanning until input开发者_StackOverflow is received in this window...

Could I do this by getting thread ID?

user .ShowDialog()

if you window is named secondRibbonWindow then use

secondRibbonWindow.showDialog();