Develop Reference

Functionality to treat floating tabs as separate from main window

Context: I launch my main window. Within that window I create three new tabs. I float two of the tabs and leave the other within the main window. There are two problems I am currently trying to tackle:
I want to be able to minimize the main window without hiding my other floating tabs as well.
When shifting focus to another program (e.g. Chrome) then clicking back on my floating tab, I don't want all my other floating tabs + the main window to be brought back to front, in effect hiding my other program.
I believe this should be possible since the Visual Studio UI is built using WPF and I can achieve this functionality using floating tabs in VS.

Yes you can do this. The reason why it is being minimized is because the default owner of the floating window is the main window. so you have to set the floatingWindow.Owner = null; then you will also be able to put the main window in front of the floating window. if you want to switch between floating window and main window you can set floatingWindow.ShowInTaskbar = true;.
In my code i put it in a selectionChanged event handler so when i pop out a document it fires the selectionChanged event.
Document creation
private void userItem_Click(object sender, RoutedEventArgs e)
{
LayoutDocument ld = new LayoutDocument();
ld.Title = "All Users";
ld.ToolTip = "Manage all users";
//selection changed event
ld.IsSelectedChanged += Ld_IsSelectedChanged;
ld.IsActiveChanged += Ld_IsSelectedChanged;
Users users = new Users(ld);
ld.Content = users;
LayoutDocumentPane pane = ((todaysPayments.FindParent<LayoutDocumentPane>() ?? (panal.Children?[0] as LayoutDocumentPane)) ?? new LayoutDocumentPane());
pane.Children.Add(ld);
if (panal.ChildrenCount == 0)
{
panal.Children.Add(pane);
}
ld.IsSelected = true;
}
And the event handler
public void Ld_IsSelectedChanged(object sender, EventArgs e)
{
//get the floating windows from the DockingManager
manager.FloatingWindows.ToList().ForEach(floatingWindow =>
{
floatingWindow.Owner = null;
floatingWindow.ShowInTaskbar = true;
var fw = floatingWindow.Model as LayoutDocumentFloatingWindow;
floatingWindow.Title = fw?.RootDocument?.Title ?? "";
});
}

How can I hide a window WITHOUT Visibility property?

I have an application that has a lot of modal popup windows. Some are custom windows displayed with .ShowDialog(), other are generic message boxes using a 3rd party tool (DXMessageBox.Show(...)), and others are system dialogs such as an OpenFileDialog. If the user leaves the application running long enough, it should time out and show a "Session Locked" screen and prevent users from seeing or interacting with the application until they login again. This is problematic because of the modal dialogs.
My current solution is to host the Relogin screen in the current modal window if there is one, and hide all other windows. The problem is that if I set Visibility = Hidden on any window I have called using .ShowDialog(), it treats that dialog as having received a result and processes the code that handles the dialog result. They are also no longer modal after they are re-shown.
So my current attempt is to try to hide the window using something other than Visibility, and prevent it from being activated. The closest I've come is by setting Minimized=true and ShowInTaskbar=false, but this results in an undesirable minimized titlebar above my taskbar.
Is there a way to prevent this from happening, or alternatively is there another way to hide a window and prevent it's activation without causing .ShowDialog to return?
Here's some code to re-create a sample application to test this with. Just add a button to launch the ShowLock_Click event handler.
private readonly Dictionary<System.Windows.Window, WindowStyle> _hiddenWindows = new Dictionary<System.Windows.Window, WindowStyle>();
// Create a button to launch this for testing
private void ShowLock_Click(object sender, RoutedEventArgs e)
{
// Will show another window with .ShowDialog, then 2s timeout will trigger lock window
using (new System.Threading.Timer(OnLockTimerElapsed, null, 2000, System.Threading.Timeout.Infinite))
{
ShowTestDialog();
}
}
private void OnLockTimerElapsed(object state)
{
_hiddenWindows.Clear();
Application.Current.Dispatcher.BeginInvoke(
DispatcherPriority.Background,
new Action(() =>
{
var mainWindow = Application.Current.MainWindow;
Window host = null;
foreach (Window win in Application.Current.Windows)
{
if (IsModalDialog(win))
host = win;
_hiddenWindows.Add(win, win.WindowStyle);
// Been testing various ways to hide window without using Visibility
win.ShowInTaskbar = false;
win.WindowStyle = WindowStyle.None;
win.WindowState = WindowState.Minimized;
win.Opacity -= 1;
win.IsHitTestVisible = false;
}
ShowLockScreen(host);
}));
}
private void ShowLockScreen(Window owner = null)
{
var lockScreen = new Window
{
Title = "Relogin Window",
Content = "This is a test Relogin Window. Close Window via X to continue",
WindowStartupLocation = WindowStartupLocation.CenterScreen
};
if (owner != null)
lockScreen.Owner = owner;
lockScreen.ShowDialog();
// Once that window closes, restore other windows
RestoreSession();
}
private void RestoreSession()
{
Application.Current.Dispatcher.BeginInvoke(
DispatcherPriority.Background,
new Action(() =>
{
foreach (var win in _hiddenWindows.Keys)
{
win.ShowInTaskbar = true;
win.WindowStyle = _hiddenWindows[win];
win.WindowState = WindowState.Normal;
win.IsHitTestVisible = true;
win.Opacity += 1;
}
}));
}
private void ShowTestDialog()
{
var test = new Window
{
Title = "Test Modal Dialog",
Content = "This is a test Modal Dialog. Close window via X to continue.",
Height = 100,
Width = 350,
WindowStartupLocation = WindowStartupLocation.CenterOwner,
Owner = this
};
var result = test.ShowDialog();
// This code gets run if I set Visibility=Hidden. I do not want that.
MessageBox.Show($"Test Dialog result returned. Result : {result}. This should ONLY happen when you click X on the dialog window");
}
private static bool IsModalDialog(Window window)
{
return (bool)typeof(System.Windows.Window)
.GetField("_showingAsDialog", System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.NonPublic)
.GetValue(window);
}

WPF | Send Info from Popup Child Window to Parent Window

i have this WPF application in which i am trying to make popup window. well window is created and working fine, but what i want to do. that if i press OK/Update button in that popup, The selected values should be passed the the parent window and that popup should be closed.
i have seen this problem solution here..
C# - Return variable from child window to parent window in WPF
But i do not understand how this delegates works..
I have done it like this..
When click on button this method will opens the popup window.
private void btnAddBeneficiaryPopup_Click(object sender, RoutedEventArgs e)
{
try
{
AddBeneficiaryPopup addBen = new AddBeneficiaryPopup(refCustId);
addBen.selectedBeneID += value => selectedBeneficiaryID = value;
addBen.Show();
}
catch (Exception ex)
{ this.MyErrorMessage(ex); }
}
In Popup window in the constructor i have code like this.
public AddBeneficiaryPopup(int id)
{
InitializeComponent();
refCustId = id;
this.LoadReferenceBeneficiary();
}
Now this below Method i am working on and want to change it mostly..
private void cmbRefBene_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
string beneId = null;
if (cmbRefBene.SelectedIndex >= 0)
{
try
{
beneId = ((DataRowView)cmbRefBene.SelectedItem).Row.ItemArray[0].ToString();
selectedBeneID = beneId;
bene.OpenConnection(str);
SqlDataReader reader = bene.LookUpSingleBene(int.Parse(beneId));
if (reader.Read())
{
tbName.Text = reader["Name"].ToString();
tbContactNo.Text = reader["ContactNo"].ToString();
btnUpdate.IsEnabled = true;
}
reader.Close();
bene.CloseConnnection();
}
catch (Exception ex)
{
MyErrorMessage(ex);
}
finally
{
bene.CloseConnnection();
}
}
}
As you can see in above code selectedBeneID = beneId; this beneId gives error. as i am trying to assign it selectedBeneID, as i think its a delegate to there must be another way to assigning values to it and passing it to the Parent Window..
But really am not sure how to work with this delegate and what to write to assign value to it.
i am getting error
"cannot implicitly convert type string to "System.Action<string>"

Solution A (getting your one working)
To get your solution running, change the following line in your cmbRefBene_SelectionChanged function:
selectedBeneID = beneId;
to
selectedBeneID(beneId);
Now you should not get the error message and the value should be set correctly.
Solution B
The following solution isn'n the most elegant but it always works:
Give your Popup Window a public Property (selectedBeneID).
public partial class AddBeneficiaryPopup : Window {
public string selectedBeneID;
.....
}
}
Set this property in your cmbRefBene_SelectionChanged function.
MainWindow:
change addBen.Show(); in your Main Window
to
addBen.ShowDialog();
idreturned = addBen.selectedBeneID;
Now The program will wait until you close the Popup.
After that you can access the property of your popup Window and read it out.

C# WPF - Want to open multiple windows at once, but only one instance of each window

I am new to WPF and have been hunting for an answer, surely this is not difficult?
I have created a main window with links to multiple windows, and I want them to run modelessly alongside one another, but I don't want to open multiple instances of the SAME window.
In simple terms, I can have Windows A, B, C open at once, but not Windows, A, A, B, C, C.
I need to implement a check for the window I'm trying to open (in this case, EditSettings).
If open - activate it
if not open, open it.
I have the following code in Main, which is not working.
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
}
private void MenuItem_Click(object sender, RoutedEventArgs e)
{
EditSettings winEditSettings = new EditSettings();
string isOpen = null;
if (isOpen == "true")
{
winEditSettings.Activate();
}
else
{
winEditSettings.Show();
isOpen = "true";
}
}
}
Now I know what's wrong with this logic - every time I press the button to open EditSettings, it's setting isOpen to null again. If I don't set a value to isOpen, the If condition breaks.
I could initialise the variable 'isOpen' as a public variable outside the MenuItem_Click method, but then I think I would need an isOpen variable for each window I create!! Surely there is a better way?
The other option I tried is:
private void MenuItem_Click(object sender, RoutedEventArgs e)
{
EditSettings winEditSettings = new EditSettings();
if (winEditSettings.IsLoaded)
{
winEditSettings.Activate();
}
else { winEditSettings.Show(); }
I can't figure out why this isn't working, I tried isVisible, isLoaded, isActive - nothing is stopping the window from opening more than once. Thank you for the help!

There are people who'll perhaps throw a fit at the idea, but whenever I've needed to do this, I made the child window objects part of the application. Then, in your MenuItem_Click(), test if winEditSettings is null, instead.
It's still a member variable for each window (like your provisional isOpen solution), but having the window objects available can have advantages later, if you need to bridge information between the windows. In my cases, we wanted to be able to close all the child windows together, which (most trivially) meant keeping track of those objects in a central location.
Alternatively, if you want the setup completely decoupled, you could take a singleton-like approach and put the logic into your child window classes. Specifically, you could call EditSettings.Activate and let the class keep track of whether a window needs to be created or the existing window merely Show()n.
If I were handed your code to rewrite, I'd move it something like this:
private static EditSettings winEditSettings = null;
public static void WakeUp()
{
if (winEditSettings == null)
{
winEditSettings = new EditSettings();
}
winEditSettings.Activate(); // This may need to be inside the block above
winEditSettings.Show();
}
Both of those are part of the class (static), rather than an instance. Your application object therefore calls EditSettings.WakeUp() inside the original MenuItem_Click(), and never actually sees the child window, itself.
If you change your mind about the decoupled architecture later, by the way, you can add a get accessor to your winEditSettings and keep everybody fairly happy.

if (_adCst == null)
{
_adCst = new AddCustomerPage();
_adCst.WindowStartupLocation = System.Windows.WindowStartupLocation.CenterScreen;
_adCst.WindowState = System.Windows.WindowState.Normal;
_adCst.ResizeMode = System.Windows.ResizeMode.NoResize;
_adCst.Activate(); // This may need to be inside the block above
_adCst.Show();
}
else
{
if (!_adCst.IsLoaded == true)
{
_adCst = new AddCustomerPage();
_adCst.WindowStartupLocation = System.Windows.WindowStartupLocation.CenterScreen;
_adCst.WindowState = System.Windows.WindowState.Normal;
_adCst.ResizeMode = System.Windows.ResizeMode.NoResize;
_adCst.Show();
}
_adCst.Activate();
}

My suggestion would be that you set some form of a counter. This will prevent more than one instance of the window being opened.
int windowOpen = 1;
private void button_Click(object sender, RoutedEventArgs e)
{
if (windowOpen == 1)
{
WindowA winA = new WindowA();
winA.Show();
windowOpen++; //increments windowOpen by 1, windowOpen will now = 2
}
else if (windowOpen > 1)
{
MessageBox.Show("Window is already open");
}
}
I hope this helps.

For anyone else with this question, I have found another solution - which works except that it doesn't manage to bring the open window to the front (Activate). It does, however, prevent opening the same window more than once.
foreach (Window n in Application.Current.Windows)
if (n.Name == "winEditSettings")
{ winEditSettings.Activate(); }
else
{ winEditSettings.Show(); }
Can anyone speculate on why the window is not brought to the front, with Activate()?
EDIT
For others with this question, placing the winEditSettings.Activate() outside of the foreach loop does everything I'm trying to achieve:
foreach (Window n in Application.Current.Windows)
if (n.Name == "winEditSettings")
{ }
else
{ winEditSettings.Show(); }
winEditSettings.Activate();
This will stop multiple instances of the same window from opening, and will bring the window to the front if the user attempts to reopen it.

Issue with NotifyIcon not disappearing on Winforms App

I've got a .Net 3.5 C# Winforms app. It's got no GUI as such, just a NotifyIcon with a ContextMenu.
I've tried to set the NotifyIcon to visible=false and dispose of it in the Application_Exit event, as follows:
if (notifyIcon != null)
{
notifyIcon.Visible = false;
notifyIcon.Dispose();
}
The app gets to the code inside the brackets, but throws a null ref exception when it tries to set Visible = false.
I've read in a few places to put it in the form closing event, but that code never gets hit (maybe as I don't have a form showing as such?).
Where can I put this code so it actually works? If I don't put it in, I get the annoying lingering icon in the tray until you move the mouse over it.
Cheers.
EDIT
Just something extra I've noticed...........
I'm using ClickOnce in the app.........if I just exit the app via the ContextMenu on the NotifyIcon, no exception is logged.
Just when the Application_Exit event is fired after the applicaiton has checked for an upgrade here..
private void CheckForUpdate()
{
EventLogger.Instance.LogEvent("Checking for Update");
if (ApplicationDeployment.IsNetworkDeployed && ApplicationDeployment.CurrentDeployment.CheckForUpdate())
{
EventLogger.Instance.LogEvent("Update available - updating");
ApplicationDeployment.CurrentDeployment.Update();
Application.Restart();
}
}
Does this help?

On Windows 7, I had to also set the Icon property to null. Otherwise, the icon remained in the tray's "hidden icons" popup after the application had closed. HTH somebody.
// put this inside the window's class constructor
Application.ApplicationExit += new EventHandler(this.OnApplicationExit);
private void OnApplicationExit(object sender, EventArgs e)
{
try
{
if (trayIcon != null)
{
trayIcon.Visible = false;
trayIcon.Icon = null; // required to make icon disappear
trayIcon.Dispose();
trayIcon = null;
}
}
catch (Exception ex)
{
// handle the error
}
}

This code works for me, but I don't know how you are keeping your application alive, so... without further ado:
using System;
using System.Drawing;
using System.Windows.Forms;
static class Program
{
static System.Threading.Timer test =
new System.Threading.Timer(Ticked, null, 5000, 0);
[STAThread]
static void Main(string[] args)
{
NotifyIcon ni = new NotifyIcon();
ni.Icon = Icon.ExtractAssociatedIcon(Application.ExecutablePath);
ni.Visible = true;
Application.Run();
ni.Visible = false;
}
static void Ticked(object o) {
Application.Exit();
}
}

This is what I'm doing in WPF.
I am using this in conjunction to David Anson's Minimize to tray sample app, which lets you hook up a tray icon to a window (you may have multiple windows open).
Just added this code to the constructor for MinimizeToTrayInstance.
_window.Closed += (s, e) =>
{
if (_notifyIcon != null)
{
_notifyIcon.Visible = false;
_notifyIcon.Dispose();
_notifyIcon = null;
}
};

Sometimes Application_Exit event can be raised several times
Just put notifyIcon = null; in the end
if (notifyIcon != null)
{
notifyIcon.Visible = false;
notifyIcon.Dispose();
notifyIcon = null;
}

This code worked for me
this.Closed += (a, b) =>
{
if (notifyIcon1 != null)
{
notifyIcon1.Dispose();
notifyIcon1.Icon = null;
notifyIcon1.Visible = false;
}
};

Have you overridden the dispose method of the object where you've initialised the notifyIcon to also dispose the notifyIcon?
protected override void Dispose(bool disposing)
{
if (disposing)
{
notifyIcon.Dispose();
notifyIcon = null;
}
base.Dispose(disposing);
}

before im sorry for my bad english.
if u use "end" for exit program. then dont close notify icon.
before u will close notifyicon later close form.
u need to use me.close() for run form closing
example
its work...
notifyIcon1.Icon = Nothing
notifyIcon1.Visible = False
notifyIcon1.Dispose()
Me.Close()
but its not work
End
or only
Me.Close()