I'm writing a Windows Forms Application in C#.NET
On startup, the application displays a splash screen which is running in a separate thread. Whilst the splash screen is showing, the main application is initialising.
Once the main application has finished initialising, the main form of the application is displayed, and the splash screen still shows over the top.
Everything so far is as expected.
Then, the Splash screen is closed, which causes that thread to exit. For some reason, at the point, the main application windows gets sent behind all other open Windows, notably the Windows Explorer window where you clicked the .exe file to run the application in the first place!
What could be causing the windows to suddenly jump "behind" like this?
Try calling .Activate() on your main window when your thread closes.
It's never been active, and thus has low Z-Order, so whatever is higher will naturally be above it. I had to fix this exact scenario in our app.
Don't forget! You may need to marshal the call to the correct thread using an Invoke()!
I've had this happen at times too. Bob's response is the easiest and works for me in the majority of cases. However, there have been some times where I need to use brute force. Do this via interop like this:
[DllImport("user32.dll")]
public static extern bool SetForegroundWindow(IntPtr hWnd);
Is the splash screen a Modal dialog?
I have seen this window 'jumping' if you dismiss a Modal dialog twice by setting both DialogResult and calling Hide() or close().
Code like this:
private void button1_Click(object sender, System.EventArgs e)
{
this.DialogResult = DialogResult.Abort;
this.Hide();
}
See this blog entry for all of the cases...
You can use code like this :
private void button1_Click(object sender, System.EventArgs e)
{
this.DialogResult = DialogResult.Abort;
this.Hide();
}
Thanks all!
Related
My C# application starts by opening a form. In the constructor for that form I "showDialog" an openfiledialog. After selecting a file to open, the openfile dialog closes, the file is loaded and the contents displayed in the main form but the main form is buried behind every other open window on my desktop.
I have to find it in the task bar and bring it to focus. I just started the application, I want the form to have focus.
I have written other applications that do not use the openfiledialog and when I start them the main form opens with focus as you would expect.
How do I make the main form get focus after the openfiledialog closes?
I have tried
this.focus(),
this.activate(),
this.bringtofront();
and this.TopMost = true;
None of them make any apparent difference at all.
I have research this problem extensively and this are the things everyone suggests and say work, but they don't work for me. Some have insinuated that I am violating all that is holy by trying to make my form topmost. However, I don't think very many people would like to open an application and have the main form for it show up behind everything else.
Any one have any other ideas about how to make sure my form is "in front", topmost, has focus?
When you do it this way, your application will have a brief moment where no window is available to receive the focus after the dialog closes. Windows is forced to find another window to give the focus to, that will be a window of another app. Your main window eventually appears, now behind that other's app window.
Display the dialog in an event handler of the Shown event instead. Or use the boilerplate File + Open command.
SOLUTION: this.Activate(); works but if called from the form Load event.
This will set the window on top:
[DllImport("user32.dll")]
static extern bool SetForegroundWindow(IntPtr hWnd);
private void Form1_Load(object sender, EventArgs e)
{
....
//after your code place the call to the function at the end.
SetForegroundWindow(this.Handle);
}
Althought as Mr. hans said and very well you are better off with another design.
If you can, move the ShowDialog out of the constructor, or try putting this in the constructor:
this.Shown += OnShown;
and move your ShowDialog to here:
private void OnShown(object sender, EventArgs eventArgs)
{
var result = new OpenFileDialog().ShowDialog();
}
I'm currently working on a WPF app which has multiple windows. From the "main" window, you should be able to close the entire app. Before the app will be closed, the client wants it to show a dialog box which basically asks "are you sure you want to close the app" and blocks every other window until the user answers.
I'm currently using MessageBox.Show() to create this dialog box, but for some reason it only blocks the main window.
Here's the simplest example of what I'm talking about; if you create a WPF window with two buttons:
private void openChildWindowButton_Click(object sender, RoutedEventArgs e)
{
var window = new ChildWindow();
window.Show();
}
private void openDialogButton_Click(object sender, RoutedEventArgs e)
{
MessageBox.Show(this, "This should freeze all other windows");
}
Opening a dialog will completely freeze the first window. If you click on it or attempt any sort of interaction, the OS makes a "ding!" sound and flashes the border on the message box. But all of the other windows you've opened can be clicked, moved, resized, etc., and that's what I want to prevent.
As it turns out, there is a way to do this, but it's not pretty. It involves using the WinForms version of MessageBox and passing an undocumented option as the last property.
var result = System.Windows.Forms.MessageBox.Show("Are you sure you want to exit this app?", "Exit", System.Windows.Forms.MessageBoxButtons.YesNo, System.Windows.Forms.MessageBoxIcon.Question, System.Windows.Forms.MessageBoxDefaultButton.Button2, (System.Windows.Forms.MessageBoxOptions)8192 /*MB_TASKMODAL*/);
Source: http://social.msdn.microsoft.com/Forums/vstudio/en-US/8d1bd4a2-455e-4e3f-8c88-7ed49aeabc09/messagebox-is-not-applicationmodal?forum=wpf
Hopefully this is helpful to somebody else in the future!
If this works in WPF like in Windows Forms you could just use:
MessageBox.ShowDialog()
chris
Above not working...
Edit:
But there is a workaround: style a Form like a MessageBox (use a fixed Border-Type) and then Show it using ShowDialog(). Then set the Forms Cacel and Ok Button in Properties to your Buttons and you can get a DialogResult just like in a MessageBox. Hope that Helps but it is also from Windows-Forms ;)
Currently I am developing a windows form application in c# that has several forms.
I am running a background form that operates the notifyicon property that allows the icon to appear in the taskbar.
When I launch the program, it will launch a loginForm, after which logging in it will go into a mainForm. After closing the mainForm, the application does not close yet, which in this case works like Windows Live Messenger.
How do I make my program in a way that after I the mainForm, through double clicking it will bring the form back up? (Like how MSN works.)
Or is it a better solution for me to close the whole application when I press the X button in the title bar. Which brings up another problem for me as I cant seem to exit the application when I close other forms other than the main form.
Probably you have NotifyIcon on your main form. Subscribe on the DoubleClick event of this control and change state of your main form in the handler:
private void notifyIcon1_DoubleClick(object sender, EventArgs e)
{
this.Show();
this.Visible = true;
this.WindowState = FormWindowState.Normal;
}
Just set the Visible property of the form to true/false. Or you could call Show()/Hide().
I want to hide my form while keeping my application running in background.
I've used notifyIcon and it remains always visible.
I've used "this.Hide();" to hide my form but unfortunately my application gets close (no exception).
I am also using threading and this form is on second thread.
Please tell me how can I solve it.
I am also using threading and this form is on second thread.
My crystal ball says that you've used ShowDialog() to show the form. Yes, calling Hide() on a modal dialog will close it. Necessarily so, a modal dialog normally disables all of the windows in the application. If you hide it then there's no way for the user to get back to the program, there are no windows left to activate. That this form runs on another thread otherwise doesn't factor into the behavior.
You'll need to call Application.Run(new SomeForm()) to avoid this. Now it isn't modal and you can hide it without trouble. But really, do avoid showing forms on non-UI threads. There's no reason for it, your main thread is already quite capable.
add the following event handlers for form resize and notify icon click event
private void Form_Resize(object sender, EventArgs e)
{
if (WindowState == FormWindowState.Minimized)
{
this.Hide();
}
}
private void notifyIcon_Click(object sender, EventArgs e)
{
this.Show();
this.WindowState = FormWindowState.Normal;
}
but this is not close you application
I am working on learning Windows Forms with C# and have a bare bones application. I am trying to close it when the user selects File->Exit. I have an event handler attached to it and I have tried calling Application.Exit(), Application.ExitThread() and just closing the form. Nothing. It stays there. I'm not creating any other threads of any sort either.
Ideas? Thanks.
Have you tried to put a breakpoint in the event handler to see if it is being hit?
If so, the application won't exit if the window messages aren't being delivered (i.e. the UI thread is blocked). One way to test this is to call Environment.Exit() which is more brutal about forcing a close. If this succeeds, you can then figure out why Application.Exit() isn't working.
Application.Exit isn't the normal way to close a GUI application. Use form.Close instead.
private static void OnMenuClose_Click(object sender, System.EventArgs e)
{
Form dlg = ((Control) sender).FindForm();
//dlg.DialogResult = DialogResult.OK;
dlg.Close();
}