how to close all the open form in WPF - wpf

Question

In my Application I have two buttons "open" and "close".
When I click open button window will be opened, when I click close button window will be closed.
When I click open button 3 times, 3 windows will be opened. I want to close all window when I click close button.
Here is my code [Please don't try to Change the Thread because that is my requirement in my Application]
public partial class MainWindow : Window
{
Window ProgressWindow;
Thread ProgressThread;
public MainWindow()
{
InitializeComponent();
}
private void Open_Click(object sender, RoutedEventArgs e)
{
ProgressThread = new Thread(() =>
{
ProgressWindow = new Window();
ProgressWindow.Margin = new Thickness(0, 0, 50, 0);
ProgressWindow.WindowState = WindowState.Normal;
ProgressWindow.WindowStartupLocation = WindowStartupLocation.CenterScreen;
ProgressWindow.Height = 180;
ProgressWindow.Width = 180;
ProgressWindow.Content = "Hello WPF";
ProgressWindow.ShowInTaskbar = false;
ProgressWindow.Show();
ProgressWindow.Closed += (sender2, e2) =>
ProgressWindow.Dispatcher.InvokeShutdown();
System.Windows.Threading.Dispatcher.Run();
});
ProgressThread.SetApartmentState(ApartmentState.STA);
ProgressThread.Start();
}
private void Close_Click(object sender, RoutedEventArgs e)
{
if (ProgressThread.IsAlive == true)
{
ProgressThread.Abort();
}
}
}

Answer 1

I would recommend to store references to created windows, your code can look like this:
Stack<Window> ProgressWindow=new Stack<Window>();
Thread ProgressThread;
private void Open_Click(object sender, RoutedEventArgs e)
{
ProgressThread = new Thread(() =>
{
var window = new Window();
window.Margin = new Thickness(0, 0, 50, 0);
window.WindowState = WindowState.Normal;
window.WindowStartupLocation = WindowStartupLocation.CenterScreen;
window.Height = 180;
window.Width = 180;
window.Content = "Hello WPF";
window.ShowInTaskbar = false;
window.Show();
window.Closed += (sender2, e2) =>
window.Dispatcher.InvokeShutdown();
ProgressWindow.Push(window);
System.Windows.Threading.Dispatcher.Run();
});
ProgressThread.SetApartmentState(ApartmentState.STA);
ProgressThread.Start();
}
private void Close_Click(object sender, RoutedEventArgs e)
{
while (ProgressWindow.Count > 0)
{
ProgressWindow.Pop().Close();
}
}
thread aborting is not recommended if it is "normal" workflow of your application, i.e. window wasn't closed because of some critical error

Answer 2

I wouldn't recommend what you are doing and actually I don't really know if it works like this, but since you stated that it's your (strange) requirement to use threads like this, I will only comment on the actual problem:
You should save the threads in a List and then close all the threads from this list.
Edit:
public partial class MainWindow : Window
{
Window ProgressWindow;
List<Thread> ProgressThreads = new List<Thread>();
public MainWindow()
{
InitializeComponent();
}
private void Open_Click(object sender, RoutedEventArgs e)
{
ProgressThreads.Add(new Thread(() =>
{
ProgressWindow = new Window();
ProgressWindow.Margin = new Thickness(0, 0, 50, 0);
ProgressWindow.WindowState = WindowState.Normal;
ProgressWindow.WindowStartupLocation = WindowStartupLocation.CenterScreen;
ProgressWindow.Height = 180;
ProgressWindow.Width = 180;
ProgressWindow.Content = "Hello WPF";
ProgressWindow.ShowInTaskbar = false;
ProgressWindow.Show();
ProgressWindow.Closed += (sender2, e2) =>
ProgressWindow.Dispatcher.InvokeShutdown();
System.Windows.Threading.Dispatcher.Run();
}));
ProgressThread.SetApartmentState(ApartmentState.STA);
ProgressThread.Start();
}
private void Close_Click(object sender, RoutedEventArgs e)
{
foreach(var ProgressThread in ProgressThreads)
{
if (ProgressThread.IsAlive == true)
{
ProgressThread.Abort();
}
}
}
}

Answer 3

You will need to keep a record of all threads you have opened when you click "Open". Then in your "Close" method loop over that list closing each one.
Member variable:
List<Thread> allThreads = new List<Thread>();
Then in your open handler add:
allThreads.Add(ProgressThread);
Then your close handler becomes:
foreach (Thread thread in allThreads)
{
if (thread.IsAlive)
{
thread.Abort();
}
}
That what you are trying is unorthodox should go without saying.