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 ;)
Related
It is possible that when I use:
MessageBox.Show("hello");
..to still use the form but the MessageBox is open like a second window?
because currently, when I show the MessageBox, I need to first click yes or no then I can use my form again.
Yes, you can!
If you simply want to display a MessageBox, don't care what happens with it, and don't want to wait until it's closed, you may launch it on a separate thread. The easiest way to do that would be using Task.Run().
Here's an example:
private void button1_Click(object sender, EventArgs e)
{
Task.Run(() => MessageBox.Show("hello"));
// The remaining code will run without waiting for the MessageBox to be closed.
}
A couple of notes worth mentioning:
Only use this for simple message boxes where you don't care about the result. If you want to act based on the result and execute something (on the main thread), things get a little bit trickier.
You won't be able to keep the MessageBox on top of the form. Once you interact with the form, it will come on top. If you need to keep the MessageBox on top and still have the ability to interact with the form, a custom MessageBox (i.e., form) would be better in that case because you can set the Owner property to keep it on top.
No. The application focus remains on the Message Box until it is dismissed. According to the documentation:
It is a modal window, blocking other actions in the application until the user closes it.
What you can do is create your own form, style it to look like a standard Message Box, and show that form using the .Show() functionality on an instance of it:
var messageBox = new MyCustomMessageBox("hello");
messageBox.Show();
If you want the functionality to be identical in usage, you could even add a static method to your custom form which encapsulates it:
public static void Show(string message)
{
new MyCustomMessageBox(message).Show();
}
Though what I wouldn't recommend doing is calling your custom form MessageBox, that would just be asking for confusion.
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 have written a simple MSN-style program that will send and retrieve messages using WCF. The main form contains a Textbox to type in the message to be sent. In the background the application polls the server every few seconds for new messages. When a new message is received a new window is opened to display it. This has to be done on the UI thread using the Dispatcher class.
The problem is that when the new window is shown, the focus shifts away from the TextBox, so that typing is interrupted. This is very annoying! In MSN Messenger it is possible to continue typing your own message while receiving one. How is it done?
As a workaround I postpone the popup with the new message while the TextBox has focus, but there should be a better way!
The answer is simple: Since .NET 3.5 SP1 WPF forms have a ShowActivated property. Set this to false and any form thus marked won't steal no focus no more!
You could set the Focusable property of the window to false.
In my application I need to show a notification Window on top of all other windows while my MainWindow is minimized, but without stealing the focus.
So I just do this:
private void Window_Loaded(object sender, RoutedEventArgs e)
{
this.Topmost = true;
this.Topmost = false;
}
General description of application:
Main form as MDI Container. On application start, if there is no xml file for database configuration (it is checked in Main form) Main form i call another form as showdialog() to fill all database info to build connection string. Then i close form and open another for login, then i get back to Main form, which has Split Container (2 panels: 1-menu on top, 2-content from child forms).
I open forms with:
private void PlanButton_Click(object sender, EventArgs e)
{
plan.TopLevel = false;
KontenerMenu.Panel2.Controls.Add(plan);
plan.Dock = DockStyle.Fill;
plan.Show();
}
and close form with:
private void Plan_FormClosing(object sender, FormClosingEventArgs e)
{
e.Cancel = false;
this.Hide();
}
Problems i have with app:
1. When i hit Cancel button when i open ShowDialog() form for database app crashes. Cancel button is simply:
private void cancelButton_Click(object sender, EventArgs e)
{
Application.Exit();
}
2. I have problem with clicking button to open/close/open again child forms. When i hit 'X' and want o open, app crashes with exception that it cannot refer to non-existing object
3. I have several buttons when i hit one and then another one it is always below the first one and not on the top
4. For example my form is 200x200 and in right down corner i have button (so location let's say 190x190) and i hit maximize button. My button is still on 190x190 and i would like to have it on down right corner. I couldn't find any property for that. Is there any or i have to write some code for that.
I'm not sure I understood your questions. Please make them clear.
But as an answer to question #4, there's an anchor property that does what you want.
Instead of trying to exit the application from within the dialog form itself you should return a DialogResult value and test that in the main form. The cancel button on the dialog doesn't need any code, just set its DialogResult property to 'Cancel' and if you have an Ok button set its DialogResult to 'OK'.
DialogForm f = new DialogForm();
DialogResult r = f.ShowDialog();
if (r == DialogResult.Cancel)
{
Close();
}
I can immediately see a number of problems with you code, including:
If you're going to add controls dynamically using Controls.Add, you should make sure the controls you're adding are dynamically created using new(). I get a sense that you don't have a clear understanding of object lifetimes and the WindowForms control life cycle.
The Application.Exit method should be used only in unusual cases. It's purpose is to achieve exactly the result you're observing - to immediately "crash" the application. The easiest way to have a button close a modal dialog is the set the DialogResult property of the button.
Winforms has a very elegant system for placement of control on a variable sized window. In order to use this system, you should familiarize yourself with the Anchor and Dock properties that are available on all controls.
It looks like what you're doing is attempting to learn WinForms by trial and error. You can do this, but it will take much longer and be much more painful that getting a hold of a good tutorial, book, or perhaps even attending a class if you can manage it. That will allow you to take these issues one at a time and have a much more enjoyable learning experience.
I have two form classes (Form1 and Form2) in a Winforms App.
Form1 is like this:
Form2 is like this (ShowInTaskbar = false):
And this code on Form1:
Form2 someForm = new Form2();
private void btOpenAnotherWindow_Click(object sender, EventArgs e)
{
if (someForm.ShowDialog(this) == DialogResult.OK)
MessageBox.Show("OK!!!");
else
MessageBox.Show("Not OK.");
}
That is, a window with a button which opens modally another windows when clicked, and waits for the user to close the second window (by clicking the "OK" or "Cancel" button). And depending how it was closed, do alternating actions (represented here by the MessageBox.Show() calls).
I need:
The user can use only one window at a time. (Modal forms, That's why I used ShowDialog() instead of Show())
When the form closes, do something depending on how the form was closed (the "if (someForm.ShowDialog(this)...")
To be able (as a user) to minimize the WHOLE APP.
To be able to "unminimize" the app to the former state correctly.
The program to respond to WIN+M (minimize all) keys combination.
the above example fails in two ways:
(need 5) Doesn't respond to WIN+M
(need 3) The app seems to minimize when the Minimize title bar button is clicked, but it is an illusion because the main form (Form1) does not minimize and it is in fact just hidden behind the other opened windows. Only running the example with an empty desktop shows what really happens. Pics follow:
Before Minimize button is clicked:
After:
Note:
The Main form is not minimized
The Form2 is in the left botton corner of the screen.
Form2 is a full blown window (not a dialog window per se) and I need the user to interact with it only until it is closed and I also need the user to be able to miminize the whole app in case he needs it.
It is a shame I can't post here the real forms, It would be clearer than these mock-ups.
I need a solution that works with many levels of modal windows (not only two as this example shows). Any suggestions?
I may need a little more information about what you're trying to do here. I have a simple form (Form1) with a button on it, which calls this code:
private void button1_Click(object sender, EventArgs e)
{
Form1 form2 = new Form1();
form2.ShowDialog();
}
When I click the button, I get a second instance of the same form, but it's modal. I still have the option to minimize this second modal form (I obviously can't interact with the first form), and when I do minimize the second form it does minimize the entire application (both forms). Now obviously you're asking the question, so I don't think I'm understanding you. =) What about this scenario do you wish to change?
C
There is probably some way to hack this functionality using API calls, but I would probably suggest doing some type of overlay with a control inside your main form rather than an actual window. This would allow you to make it "modal" and still have the ability to minimize/resize the main window.