Re: How to remain WPF Window always on top of all windows? - C# Discussion Boards

Member 10476529 wrote:
Now I need to kepp this WPF-Window to be ALWAYS on top.

Bad idea[^]. If it is an overlay, then you want to set the owners' form as its parent, so it is always on top of that.

The utility will not work differently from the property. If you "need" this functionality anyway, check out SO[^] for a suggestion.

Bastard Programmer from Hell Suspicious | :suss:

If you can't read my code, try converting it here[^]

Yes, I "need" this functionality absolutely.
It's an Overlay that has to be used for restarting when other apps hung oder havin some kind of error messages.

I tried your link but can't sign my app ?!?
I set the manifest this way:

C#

<requestedExecutionLevel level="asInvoker" UiAccess="true" />

But then I get the Message from SharpDevelop:

CSS

Unhandled WPF exception
Exception thrown:
System.ComponentModel.Win32Exception (0x80004005): Diese Anwendung konnte nicht gestartet werden, da die Side-by-Side-Konfiguration ungültig ist. Weitere Informationen finden Sie im Anwendungsereignisprotokoll. Weitere Details können auch mit dem Befehlszeilentool sxstrace.exe angezeigt werden
   at System.Diagnostics.Process.StartWithShellExecuteEx(ProcessStartInfo startInfo)
   at System.Diagnostics.Process.Start()
   at System.Diagnostics.Process.Start(ProcessStartInfo startInfo)
   at ICSharpCode.SharpDevelop.Services.WindowsDebugger.StartWithoutDebugging(ProcessStartInfo processStartInfo)
   at ICSharpCode.SharpDevelop.Project.DefaultProjectBehavior.Start(Boolean withDebugging)
   at ICSharpCode.SharpDevelop.Project.ProjectBehavior.Start(Boolean withDebugging)
   at ICSharpCode.SharpDevelop.Project.ProjectBehavior.Start(Boolean withDebugging)
   at ICSharpCode.SharpDevelop.Project.ProjectBehavior.Start(Boolean withDebugging)
   at ICSharpCode.SharpDevelop.Project.ProjectBehavior.Start(Boolean withDebugging)
   at ICSharpCode.SharpDevelop.Project.AbstractProject.Start(Boolean withDebugging)
   at ICSharpCode.SharpDevelop.Project.Commands.Execute.<>c__DisplayClass1.<Run>b__0(Object param0, EventArgs param1)
   at ICSharpCode.SharpDevelop.Project.Commands.AbstractBuildMenuCommand.OnBuildComplete(EventArgs e)
   at ICSharpCode.SharpDevelop.Project.Commands.AbstractBuildMenuCommand.CallbackMethod(BuildResults results)
   at ICSharpCode.SharpDevelop.Project.BuildEngine.<ReportDone>b__3()
   at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
   at MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(Object source, Delegate method, Object args, Int32 numArgs, Delegate catchHandler)

---- Recent log messages:
13:32:18.552 [1] DEBUG - ActiveWorkbenchWindowChanged to [AvalonWorkbenchWindow: WpfModalDialog*]
13:32:18.552 [1] DEBUG - NavigationService
	ActiveViewContent: WpfModalDialog
	          Subview: TabPageText
13:32:18.552 [1] DEBUG - ActiveViewContentChanged to ICSharpCode.SharpDevelop.Project.Dialogs.ProjectOptionsView
13:32:22.153 [1] DEBUG - Activated feature 'ICSharpCode.SharpDevelop.Project.Commands.ExecuteWithoutDebugger', activation=Toolbar
13:32:22.161 [1] DEBUG - Activated feature 'ICSharpCode.SharpDevelop.Project.BuildEngine.Build'
13:32:22.162 [1] INFO - Start building WpfModalDialog
13:32:22.162 [1] DEBUG - CompilerMessageView: Combined 2 appends.
13:32:22.162 [26] DEBUG - Setting property CurrentSolutionConfigurationContents to '<SolutionConfiguration><ProjectConfiguration Project="{38951BDB-95FB-46CE-900E-0B4FF29292F9}">Release|AnyCPU</ProjectConfiguration></SolutionConfiguration>'
13:32:22.162 [26] DEBUG - Setting property SolutionDir to 'C:\temp\SharpDevelop\wpfmodaldialog\'
13:32:22.162 [26] DEBUG - Setting property SolutionExt to '.sln'
13:32:22.162 [26] DEBUG - Setting property SolutionFileName to 'WpfModalDialog.sln'
13:32:22.162 [26] DEBUG - Setting property SolutionName to 'WpfModalDialog'
13:32:22.162 [26] DEBUG - Setting property SolutionPath to 'C:\temp\SharpDevelop\wpfmodaldialog\WpfModalDialog.sln'
13:32:22.263 [17] DEBUG - Received command ReportEvent
13:32:22.309 [17] DEBUG - Received command ReportEvent
13:32:22.322 [17] DEBUG - Received command ReportEvent
13:32:22.581 [17] DEBUG - Received command ReportEvent
13:32:22.873 [17] DEBUG - Received command ReportEvent
13:32:22.889 [17] DEBUG - Received command ReportEvent
13:32:22.892 [17] DEBUG - Received command ReportEvent
13:32:22.893 [17] DEBUG - Received command BuildDone
13:32:22.894 [17] INFO - Finished building WpfModalDialog, success=True
13:32:22.894 [17] INFO - Start building WpfModalDialog
13:32:22.894 [14] INFO - Finished building WpfModalDialog, success=True
13:32:22.895 [1] INFO - Debugger Command: Start (withDebugger=False)

---- Post-error application state information:
Installed 3rd party AddIns: 
Workbench.ActiveContent: ICSharpCode.SharpDevelop.Project.Dialogs.ProjectOptionsView
ProjectService.OpenSolution: [Solution: FileName=C:\temp\SharpDevelop\wpfmodaldialog\WpfModalDialog.sln, HasProjects=True, ReadOnly=False]
ProjectService.CurrentProject: [CSharpProject: WpfModalDialog]

And when I start my exe it gaves me an Side-By-Side Error:

CSS

Fehler beim Generieren des Aktivierungskontextes für "C:\temp\SharpDevelop\wpfmodaldialog\WpfModalDialog\bin\Release\Test.exe".
Fehler in Manifest- oder Richtliniendatei "C:\temp\SharpDevelop\wpfmodaldialog\WpfModalDialog\bin\Release\Test.exe" in Zeile 18.
Das "UiAccess"-Attribut ist in diesem Kontext nicht zulässig im requestedExecutionLevel-Element.

modified 22-Sep-15 8:08am.

Did you sign it the executable before running?

As SO notes, it is not some trivial task; the UiAccess element is described on MSDN, here[^]. Will also require the other steps before it runs.

If I read the post right, you could skip a step if you modify the registry.

Bastard Programmer from Hell Suspicious | :suss:

If you can't read my code, try converting it here[^]

modified 22-Sep-15 8:24am.

Tried UiAccess-methode seperate times => doesn't work Frown | :(

So I tried this:
Keep my application on top[^]

It is now implemented in the App.xaml.cs this way:

C#

namespace Technewlogic.Samples.WpfModalDialog
{	
	/// <summary>
	/// Interaction logic for App.xaml
	/// </summary>
	public partial class App : Application
	{
        public bool TopMost { get; private set; }
        // couldn't find a .NET-way to bring the window
        // to top, reverting to old Win32 functions...
        [System.Runtime.InteropServices.DllImport("User32.dll", CharSet = CharSet.Unicode)]
        public static extern Int32 FindWindow(String lpClassName, String lpWindowName);
        [System.Runtime.InteropServices.DllImport("User32.dll", CharSet = CharSet.Unicode)]
        public static extern Int32 SetForegroundWindow(int hWnd);
        
        private void triMain_Click(object sender, System.EventArgs e)
        {
            int hWnd = FindWindow(null, "Test"); // Win32 API, don't want to use this
            SetForegroundWindow(hWnd); // Win32 API, don't want to use this
            TopMost = true;
            Show();
        }

        private void Show()
        {
            throw new NotImplementedException();
        }
...

Is there a method to put a timer in this so the application always becomes TopMost (about every 10 seconds)?

Benjamin.Buhr wrote:
Is there a method to put a timer in this so the application always becomes TopMost (about every 10 seconds)?

IIRC, then WPF has its own timer. Here[^] it is.

Execute your "triMain_Click" code whenever the timer fires.

Bastard Programmer from Hell Suspicious | :suss:

If you can't read my code, try converting it here[^]

I tried it this way:

C#

	...
public partial class App : Application
	{
        // 24.09.2015: Timer in WPF
        private void Window_Loaded(object sender, RoutedEventArgs e)
        {
            System.Windows.Threading.DispatcherTimer dispatcherTimer = new System.Windows.Threading.DispatcherTimer();
            dispatcherTimer.Tick += new EventHandler(dispatcherTimer_Tick);
            dispatcherTimer.Interval = new TimeSpan(0, 0, 10);
            dispatcherTimer.Start();
        }

        private void dispatcherTimer_Tick(object sender, EventArgs e)
        {
            //listBox1.Items.Add(DateTime.Now.ToString("HH:mm:ss"));
            //System.Windows.Input.CommandManager.InvalidateRequerySuggested();
            //listBox1.Items.MoveCurrentToLast();
            //listBox1.SelectedItem = listBox1.Items.CurrentItem;
            //listBox1.ScrollIntoView(listBox1.Items.CurrentItem);
            SystemSounds.Beep.Play();
            InitializeComponent();
        }

        // 24.09.2015: Keep my application on top
        public bool TopMost { get; private set; }
...

I included a Beep to check if the timer is fired - but no sound appears???

Do I have to include this in the MainWindow?

You've declared and created the timer in a method; I'd assume it gets disposed as soon as it exits the method. Try something like below;

C#

public partial class App : Application
	{
            System.Windows.Threading.DispatcherTimer dispatcherTimer = new System.Windows.Threading.DispatcherTimer();

        // 24.09.2015: Timer in WPF
        private void Window_Loaded(object sender, RoutedEventArgs e)
        {

Bastard Programmer from Hell Suspicious | :suss:

If you can't read my code, try converting it here[^]

It's a little bit confusing now ... I found one mistake :-|
The App.xaml is defined this way:

C#

<Application x:Class="Technewlogic.Samples.WpfModalDialog.App"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
	Startup="Application_Startup">
	
    <Application.Resources>
    </Application.Resources>
	
</Application>

So I had to correct the fiering of the timer in the App.xaml.cs this way:

C#

using System;
using System.Runtime.InteropServices;
using System.Security;
using System.Threading;
using System.Windows;

namespace Technewlogic.Samples.WpfModalDialog
{	
	/// <summary>
	/// Interaction logic for App.xaml
	/// </summary>
	public partial class App : Application
	{
        // 24.09.2015: Timer in WPF
        System.Windows.Threading.DispatcherTimer dispatcherTimer = new System.Windows.Threading.DispatcherTimer();
        private void dispatcherTimer_Tick(object sender, EventArgs e)
        {
            TopMost = true;
            this.TopMost = true;
            //MessageBox.Show("Popup: dispatcherTimer_Tick");
            InitializeComponent();
        }

        // 24.09.2015: Keep my application on top
        public bool TopMost { get; set; }
        // couldn't find a .NET-way to bring the window
        // to top, reverting to old Win32 functions...
        [SuppressUnmanagedCodeSecurity]
        public class SafeNativeMethods
        {
            [System.Runtime.InteropServices.DllImport("User32.dll", CharSet = CharSet.Unicode)]
            public static extern Int32 FindWindow(String lpClassName, String lpWindowName);
            [System.Runtime.InteropServices.DllImport("User32.dll", CharSet = CharSet.Unicode)]
            public static extern Int32 SetForegroundWindow(int hWnd);
        }

        private void triMain_Click(object sender, System.EventArgs e)
        {
            int hWnd = SafeNativeMethods.FindWindow(null, "Test"); // Win32 API, don't want to use this
            SafeNativeMethods.SetForegroundWindow(hWnd); // Win32 API, don't want to use this
            TopMost = true;
        }

        // Only One Instance of App allowed
        private void Application_Startup(object sender, StartupEventArgs e)
		{
            // 24.09.2015: Keep my application on top + Timer in WPF
            dispatcherTimer.Tick += new EventHandler(dispatcherTimer_Tick);
            dispatcherTimer.Interval = new TimeSpan(0, 0, 1);
            dispatcherTimer.Start();

            bool createdNew;
      		Mutex mutex = new Mutex(true, this.GetType().GUID.ToString(), out createdNew);
      		if (createdNew)
      			{
                	Window window = new MainWindow();
        			window.Closed += (sender2, args) => mutex.Close(); ;
        			window.Show();
                }
      		    else
      			{
        			// MessageBox.Show("App already running...");
        			mutex.Close();
        			Application.Current.Shutdown();
      			}
		}
    }
}

I've tested the timer with a MessageBox => worked Smile | :)

But how is it possible to renew the TopMost for the MainWindow (Mainwindow.xaml.cs) or for the App?
Should I use the TopMost-Function better in the MainWindow-Element?

And I have a nother question:
This makes a CA1401:

C#

public class SafeNativeMethods
{
    [System.Runtime.InteropServices.DllImport("User32.dll", CharSet = CharSet.Unicode)]
    public static extern Int32 FindWindow(String lpClassName, String lpWindowName);
    [System.Runtime.InteropServices.DllImport("User32.dll", CharSet = CharSet.Unicode)]
    public static extern Int32 SetForegroundWindow(int hWnd);
}

How can I correct this?

My corrections didn't work Frown | :(

...

So I will now try this way:

Now my MainWindow.xaml.cs is coded this way:

C#

using System;
using System.Diagnostics;
using System.Windows;
using System.Runtime.InteropServices;

namespace Technewlogic.Samples.WpfModalDialog
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>

    public partial class MainWindow : Window
	{
        // 28.09.2015: C# Check If Application Is Already Running Then Set Focus
        [DllImport("user32.dll")]
        private static extern bool SetForegroundWindow(IntPtr hWnd);
        [DllImport("user32.dll")]
        private static extern bool ShowWindowAsync(IntPtr hWnd, int nCmdShow);
        [DllImport("user32.dll")]
        private static extern bool IsIconic(IntPtr hWnd);
            /*
            const int SW_HIDE = 0;
            const int SW_SHOWNORMAL = 1;
            const int SW_SHOWMINIMIZED = 2;
            const int SW_SHOWMAXIMIZED = 3;
            const int SW_SHOWNOACTIVATE = 4;
            const int SW_RESTORE = 9;
            const int SW_SHOWDEFAULT = 10;
            */
        const int swRestore = 9;

        // 25.09.2015: Timer fiering
        System.Windows.Threading.DispatcherTimer dispatcherTimer = new System.Windows.Threading.DispatcherTimer();
        private void dispatcherTimer_Tick(object sender, EventArgs e)
        {
            //MessageBox.Show("Popup: MainWindow_TimerTick");
            // 28.09.2015: C# Check If Application Is Already Running Then Set Focus
            var me = Process.GetCurrentProcess();
            var arrProcesses = Process.GetProcessesByName(me.ProcessName);

            if (arrProcesses.Length > 1)
            {
                for (var i = 0; i < arrProcesses.Length; i++)
                {
                    if (arrProcesses[i].Id != me.Id && arrProcesses[i].SessionId == me.SessionId)
                    {
                        // get the window handle
                        IntPtr hWnd = arrProcesses[i].MainWindowHandle;
                        // if iconic, we need to restore the window
                        if (IsIconic(hWnd))
                        {
                            ShowWindowAsync(hWnd, swRestore);
                        }
                        // bring it to the foreground
                        SetForegroundWindow(hWnd);
                        break;
                    }
                }
            }
        }

        // Main Window
        public MainWindow()
		{
			
			//Alt-Tab preventing
			Window w = new Window(); // Create helper window
        	w.Top = -100; // Location of new window is outside of visible part of screen
        	w.Left = -100;
        	w.Width = 1; // size of window is enough small to avoid its appearance at the beginning
        	w.Height = 1;
        	w.WindowStyle = WindowStyle.ToolWindow; // Set window style as ToolWindow to avoid its icon in AltTab 
        	w.Show(); // We need to show window before set is as owner to our main window
        	this.Owner = w; // Okey, this will result to disappear icon for main window.
        	w.Hide(); // Hide helper window just in case

            // 25.09.2015: Timer settings
            dispatcherTimer.Tick += dispatcherTimer_Tick;
            dispatcherTimer.Interval = new TimeSpan(0, 0, 5);
            dispatcherTimer.Start();
            //Initialisierung der Komponenten
            InitializeComponent();
			ModalDialog.SetParent(ModalDialogParent);
		}

        // ModalDialog
        private void ShowModalDialog_Click(object sender, RoutedEventArgs e)
    	{
            var res = ModalDialog.ShowHandlerDialog(MessageTextBox.Text);
			var resultMessagePrefix = "Result: ";
			if (res)
				ResultText.Text = resultMessagePrefix + "OK";
			else
				ResultText.Text = resultMessagePrefix + "Break";
		}
	}
	
}

What does "didn't work" mean? Did it throw an exception? Failed silently? Did the timer fail, or getting to topmost?

The previous link from SO is the only real supported scenario; I'd recommend focussing on that.

Bastard Programmer from Hell Suspicious | :suss:

If you can't read my code, try converting it here[^]

Sorry for giving not enough informations about the fail Frown | :(

=> getting topmost failed

There is no exception and the timer is working without errors...

If you open a normal Window, it shows in front of your window?

Does the same happen without timer?

Bastard Programmer from Hell Suspicious | :suss:

If you can't read my code, try converting it here[^]

Yes, it is shown in front of a normal window.

I think the other problem ist that I'm using UserControl in WPF.
Because of this the handle will always be 0 ... Frown | :(

Is there a way to set/create/place a handle in my WPF including UserControl?

The Console-Outputs I created always say this:

********************** Timer_Tick-Anfang ********************** 
Setze ShowWindowAsync für den System.Diagnostics.Process (Test)-Handle 0 mit dem SW_RESTORE-Parameter 9 
Setze ForegroundWindow für System.Diagnostics.Process (Test) mit dem Handle 0 
Setze TOPMOST für Prozess System.Diagnostics.Process (Test) mit dem Handle 0 
Setze TOP für Prozess System.Diagnostics.Process (Test) mit dem Handle 0 
hWnd: 0 
********************** Timer_Tick-Ende ************************

I am loading the UserControl in the main window this way:

C#

InitializeComponent();
ModalDialog.SetParent(ModalDialogParent);

Benjamin.Buhr wrote:
I think the other problem ist that I'm using UserControl in WPF.

A UserControl is not a Window, and cannot be topmost; it needs to be hosted in a Window.

Then again, it would not be very friendly to have a usercontrol modify its parents' behaviour.

In WinForms (I don't do WPF) there's an event that is fired on the form as soon as the handle is created; it is fired quickly after the constructor. That's where you could initialize your UC.

Bastard Programmer from Hell Suspicious | :suss:

If you can't read my code, try converting it here[^]

hi,

i have Windows-Mobile program that work with weight Connecting through rs232.

its work excellent - If the program works in a period of time, it starts to slow

down and even get stuck at some point.

my code:

Hide Expand Copy Code
port = new SerialPort("COM3", 9600, Parity.None, 8, StopBits.One);
port.DataReceived += new System.IO.Ports.SerialDataReceivedEventHandler(Recepcion);

private SerialPort port;
StringBuilder SB;
private void Recepcion(object sender, System.IO.Ports.SerialDataReceivedEventArgs e)
{
try
{
SB = new StringBuilder(1000);
Application.DoEvents();
System.Threading.Thread.Sleep(122);
SB.Append(port.ReadExisting());
port.DiscardInBuffer();
this.Invoke(new EventHandler(Actualizar));
}
catch { }
}

string MOMO1, MOMO2;
string[] WI;
string ALL;
private void Actualizar(object s, EventArgs e)
{
    ALL = SB.ToString().Trim();
    WI = ALL.Split(',');
    ALL = WI[2].ToString().Trim();
    MOMO1 = ALL.Replace("+", "").Replace("g", "").Replace("ST", "").Replace("GS", "").Replace("US", "");
    if (MOMO1 != "")
    {
        MOMO2 = MOMO1;
    }
    lblMSG.Font = new Font("Ariel", 48, FontStyle.Bold);
    lblMSG.Text = MOMO2;
    Check_Weight();
    GC.Collect();  // <-- is it OK ?
}

Can anyone advise me why and how to solve it ?

For starters, you should never have to call in the garbage collector yourself: it only needs to be used when you start to run out of memory.

Second, that's really rather nasty code. The DataReceived event is started on a non-UI thread, as you know (or you wouldn't be Invoking the UI), but you are changing / using the value of SB on two threads, with no checking or locking to make sure that there isn't a problem. And you Invoke the UI thread even if there is no data to play with - and DataReceived can be fired for each character received, even if you have already removed them from the buffer.
You are also creating a new Font object (which is identical to the last) potentially for each character you receive, without any attempt to dispose of them. The GC will not do that, so Graphics Handles are being used up at a frightening rate - and these do not trigger the GC to do anything.
And there is a spurious ToString in there: Split returns an array of strings, so converting its constituent parts to a string is unnecessary.

Personally?
I'd have a background task processing the data with locking to prevent problems, and only invoke the bits which update the actual UI elements. I'd also use the same Font object for the label, and not change it at all.
And Application.DoEvents is a definite no-no!
I'd probably not use Split at all - it's not particularly efficient since it creates a lot of memory you aren't using. I'd look at IndexOf and SubString instead to "pull out" just the bit you are interested in. Even if I did use Split, you really, really need to check the number of array elements it returns: The DataReceived event doesn't wait for the end of your message before it "kicks in"...

[edit]Typos[/edit]

Bad command or file name. Bad, bad command! Sit! Stay! Staaaay...

modified 22-Sep-15 5:06am.

Many thanks for the detailed answer !
If this is not hard, I'd be happy if you can change things problematic in this code.

OG has given you a detailed answer of the issues in your code, it shouldn't be too much trouble for you to convert it based off his reply. You might want to do this for yourself.

Just to add to what Pete said, I couldn't if I wanted to: I don't have access to the equipment you are connecting to, or any idea what the data looks like, or what's important about it - so I couldn't test any changes I did make!

Bad command or file name. Bad, bad command! Sit! Stay! Staaaay...

thanks for the help,
i change my code to:

private SerialPort port;
StringBuilder SB;
private void Recepcion(object sender, System.IO.Ports.SerialDataReceivedEventArgs e)
{
try
{
SB = new StringBuilder(1000);
SB.Append(port.ReadLine());
port.DiscardInBuffer();
this.Invoke(new EventHandler(Actualizar));
}
catch { }
}

but still same problem..... my program fonts change alone for no reason..... Confused | :confused:

All you have done it take out the DoEvents and the Thread.Sleep.

You have done nothing about the problems I told you about.
And you are surprised that your code has the same fault?

Are you just guessing here, or have you designed this properly?

Bad command or file name. Bad, bad command! Sit! Stay! Staaaay...

Maybe I'm not an expert like you,
I do my best.
Right now I have a problem and I'm really trying to solve it in all ways

I have around 100 Virtual Machines open in my Remote Desktop Connection Manager and I want to perform a same operation on all those machines. Can I do this using some code?

No idea. You haven't told us what operation you want to perform.

I have a Windows Desktop application opened on all the machines and I want to mark/unmark a checkbox.