What could be the reasons for the Main application form not to be shown in TaskBar?
ShowInTaskbar property is set to "true", but form doesn't show itself there if after running the application and before the Main form appears I switch to some other window. Form exists, but until I minimize apps that are above to make it visible, it won't show in Taskbar.
UPDATE. Form does not have an Owner.
I've added form.Activate() after form.Show(). Now it always jumps out when completely loaded, and doesn't get lost under some other screens.
Though it is not a solution, but a crutch, responses are welcome anyway.
Check if your main form has a Parent defined or an Owner. In either case that would exclude it from being in the task bar in its own right. Also worth trying TopMost=true.
I had the same issue with one project I wrote.
No icon showing in the Taskbar unless I forced Windows to refresh it.
It was a call to
this.MinimumSize = new Size(wid, len);
In the Form_Load that was the issue.
I had a similar issue when the program was run from an installer (InstallMate in my case). I eventually pinned the problem down to changing the form's title text (Text) in the Form1_Load() method. When I moved that title changing text to just below the InitializeComponent(); bit, the problem went away.
I hope this can help someone else, despite the specificness of my circumstances.
I had the same issue as #deegee where setting MinimumSize in the Form Load causing the non display in the Taskbar. I fixed the issue with setting the Form Visible to False then to True.
Related
I have problem with an application where modal WPF dialog occasionally goes behind the main application window. This hapens when I click button on the dialog which does some processing and updates controls (through binding) in the main application window. When it goes in background - clicking anywhere in the application brings it back into foreground.
var dialog = LoadDialogWindowThroughMEF();
dialog.Owner = Application.Current != null ? Application.Current.MainWindow : null;
dialog.ShowInTaskbar = false;
dialog.WindowStartupLocation = WindowStartupLocation.CenterOwner;
return dialog.ShowDialog();
The above code shows how I open modal window. This happens very rarely.
Does anybody know what could be the problem?
I'm not sure I have an answer for you, but I can share some of my thoughts:
Every time I've encountered this type of problem, it happened because the Owner wasn't set properly. So, I'd try to not set the Owner and see if that makes the problem reproducible. You need to be absolutely sure that Owner is set to the correct parent window at all times1. You might also want to check that it is the actual MainWindow of your application that are supposed to be the parent. I think that most of the time it is beneficial to be explicit2 in your code. In this case that means that it is better to assign the known parent (maybe you have a reference to the parent somewhere that you could use), rather than relying on the Application.Current to provide you with that reference. Doing so will put you in control of the assignment to Owner. It could even make it possible to get rid of the ?: operator since you would have the means to control the reference even during unit testing.
I also want you to make sure that the code that is actually updating the parent window doesn't in any way force focus to a specific control on the parent window, or anything like that. (As long as the correct parent is set as Owner, I don't see this as a likely problem.)
I hope this helps you, but I understand if it doesn't. The fact that your dialog reappears when you click the parent window disproves some (or all!) of my points...
1 Except when running your unit tests, but that's a completely different matter.
2 As in the first meaning of the word according to wiktionary.org/wiki/explicit, and as opposed to implicit.
Dim details As New frmDetails(ID, JobID, True)
details.ShowDialog()
The form flashes open and immediately closes. If I use Show() rather than ShowDialog() it stays open and look fine. Here are some things I've checked:
Breaking in FormClosing shows only
System.Windows.Forms.Form.OnFormClosing
System.Windows.Forms.Form.CheckCloseDialog
System.Windows.Forms.Application.ThreadContext.System.Windows.Forms.UnsafeNativeMethods.IMsoComponent.FContinueMessageLoop
System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop
System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner
System.Windows.Forms.Application.ThreadContext.RunMessageLoop
System.Windows.Forms.Application.RunDialog
System.Windows.Forms.Form.ShowDialog
between the ShowDialog and the FormClosing.
CloseReason is "None"
Load runs to the end, as does VisibleChanged (though Activated never gets called).
There's no sign of any Exceptions being thrown.
Intellitrace doesn't show anything going on.
After the form closes, the DialogResult is "Cancel" (There's no reference to DialogResult in the form or its Designer)
I'm not doing any explicit threading
I'd appreciate any suggestions either as to what's going on or how to go about finding out.
Thanks.
In my case I was setting the DialogResult property on the load event to Cancel, and that was causing the dialog to close immediately after Load. I've set it to the default None and now I only set it to other value on the Click event of a button when I really need to close it.
Well, this will probably do nobody any good, but here's how I solved the problem:
There was a line in the Load method that read
Me.Text = ""
I have no idea what it was doing there (this isn't my code, thank goodness), especially since the value gets set again later on, but taking that line out stopped the form from mysteriously closing. Go figure.
I had a similar problem. In my case it was due to not specifying the parent window on the ShowDialog(). The dialog associated with the window that was topmost, which happened to be a combobox drop-down that was going away.
In my case, I changed the ShowDialog() call to use my application's main window as the parent, and problem solved.
Been debugging for couple of hours with the same problem. In my case the likely reason was that the parent form has setting ShowInTaskbar = false in Load event, while my form had this set to true in the designer. For some reason this caused the dialog result to be set to Cancel during initialization.
I have gone around and around with this problem using a combination of show(), showdialog(), bringtofront() and activate().
I am running CF 3.5 on a symbol MC50 PocketPC running Windows Mobile 5 (I think it is 5...)
This has to be simpler. Could someone please please give me some advice on this one?
If I use form.Show() the second time nothing happens.
If I use form.ShowDialog() the second time I receive this error:
"value does not fall within expected range"
If you call form.Close(), all resources within the instance of the form and the instance itself are disposed of. If you just wish to visually close the form but keep it around, you should use form.Hide(). This issue gave me quite a bit of frustration as well. Below is a note from the Microsoft documentation regarding this:
Note:
When the Close method is called on a Form displayed as a modeless window,
you cannot call the Show method to make the form visible, because the form's
resources have already been released. To hide a form and then make it visible,
use the Control.Hide method.
I 'm running into a situation i don't understand and want somebody to enlighten me if possible.
Created a WPF application. For sake of simplicity consider this application to be one window. I put some controls on this window, amongst others there is a TextBox control (let's call it TB).
There is a requirement that this TB must always have the focus (in case someone types something or something is read through the barcode-scanner it should appear there).
I thought implementing this with the help of a timer: every second the focus is transferred to the TB.
Until now everything works fine (as expected).
The weird thing is the following: let's say a new user wants to use this window, so she has to sign in. I thought implementing this with a new Window object (let's call it W2), calling it this way:
W2.ShowDialog();
This W2 window should be modal (bear in mind that the timer still executes).
The crazy thing is that under Windows Vista this works perfectly as expected (this means W2 is modal and the user can to what she should do on W2), BUT on Windows XP as soon as the user wants to type something in a textbox of W2 the focus is set back to TB on the initial Window (as far as i can interpret: this means W2 is not modal!!!? am i right?).
How can i overcome this situation?
Is this the right approach?
Thanks in advance
Make sure to set the Owner property of W2 to your main Window.
From the referenced docs:
When you open a child window by calling ShowDialog, you should also set the Owner property of the child window.
I am not sure this setting-the-focus-back-every-few-seconds is such a good idea. It is always possible that some input will come in the interval between a lost and got focus state (and be lost). Alternative solutions are catching the PreviewKeydown event on the form that the TB resides on and somehow set the output of a barscanner to the TB too.
I have a winform app that is hiding it's UI and waiting on a named pipe message before showing up
On receiving the event the thread invokes into the main UI thread and then does the following
Set the opacity to 100
ShowInTaskbar = true;
BringToFront();
ON Windows Vista the window does not show up on the taskbar though and the window is in the background . YOu cant say it
if you finally find it and click on it, it shows up on the taskbar
any ideas on how to fix this
i don't work in vista but it might be better just to flash the taskbar or do a ballon popup or something like that. What your suggesting maybe a bit annoying to a user. Say there typing away and there looking at the keyboard and your window has stolen the focus they look back and find what they just wrote hasn't gone into the app they thought it was going into.like this.
flashing the task bar
this might help also
If the form has an Owner set it might or might not show up in the taskbar.
Don't set the Owner property and it should show fine (it did for me).