prohibit user from closing the form - c#

I have a main form called Form_Main, when somebody wants to close it, it will close the entire application (by entire application I mean quitting other forms as well). Therefore I prepared a yes/no MessageBox that ask users if they really want to quit the form. Here's where I'm at:
private void Form_Main_FormClosed(object sender, FormClosedEventArgs e)
{
DialogResult result = MessageBox.Show("Are you sure?", "Confirmation", MessageBoxButtons.OKCancel);
if (result == DialogResult.OK)
{
Environment.Exit(1);
}
else
{
//does nothing
}
}
The "OK" button works. But when users clicks "Cancel", Form_Main is closed, but the application is still running (other forms are untouched). What should I replace //does nothing with?

Use the FormClosing event (instead of FormClosed), and then set e.Cancel = true:
private void Form_Main_FormClosing(object sender, FormClosingEventArgs e)
{
var result = MessageBox.Show("Are you sure?", "Confirmation", MessageBoxButtons.OKCancel);
e.Cancel = (result != DialogResult.OK);
}
The FormClosing event occurs before the form actually closes, so you still have a chance to cancel it. By the time you get to the FormClosed event, it's too late.

Related

How can I pervent a regular user from closing my GUI, in C#? [duplicate]

I have a C# GUI application. When the user clicks on the red 'X' (for closing the app) I want to show a message and ask if he really wants to close it.
I found a solution:
DialogResult dialog = MessageBox.Show("Do you really want to close the program?", "SomeTitle", MessageBoxButtons.YesNo);
if (dialog == DialogResult.Yes)
{
Application.Exit();
}else if (dialog == DialogResult.No)
{
//don't do anything
}
When the user clicks 'yes', the application should terminate completely. (Is Application.Exit() correct for this purpose?)
When the user clicks 'no', the DialogResult/MessageBox should close, but the application should stay opened. However, it closes!!
How can I avoid this?
BTW: I use Visual Studio 2010 and Winforms.
Use the FormClosing event from the Form, and the FormClosingEventArgs to cancel the process.
example:
private void Form1_FormClosing(object sender, FormClosingEventArgs e)
{
DialogResult dialog = dialog = MessageBox.Show("Do you really want to close the program?", "SomeTitle", MessageBoxButtons.YesNo);
if (dialog == DialogResult.No)
{
e.Cancel = true;
}
}
Use the form's FormClosing event of your program window. You can then set e.Cancel to true if the user clicks no:
this.FormClosing += (s, e) => {
DialogResult dialog = dialog = MessageBox.Show("Really close?", "SomeTitle",
MessageBoxButtons.YesNo);
if (dialog == DialogResult.No)
{
e.Cancel = true;
}
};
I guess you are using FormClosed. Are you? Then it's too late.
Try this
this.FormClosing += new FormClosingEventHandler(delegate(object sender, FormClosingEventArgs e)
{
if (MessageBox.Show("Do you really want to exit this application?", MessageBoxButtons:=MessageBoxButtons.YesNo) == DialogResult.No)
{
e.Cancel = true;
}
});
Refer to Mudu's answer.
Basically unless you specify additional parameters to MessageBox.Show() you cannot get any result other than DialogResult.Ok from a default MessageBox.
The code you posted (minus your little typo of dialog = dialog =) works exactly as expected to me.
Also: Application.Exit() IS the correct way of closing an application :)

C# Dialog keeps pop up when click yes in Form_FormClosing

Adding an event in my C# winForms the FormClosing but the dialog keeps pop-up after adding the code Close()
private void AdminPanel_FormClosing(object sender, FormClosingEventArgs e)
{
DialogResult result = (MessageBox.Show(this,
"Are you sure you want to close the Application?",
"Exit",
MessageBoxButtons.YesNo, MessageBoxIcon.Question));
if (result == DialogResult.Yes)
{
//dialog keeps poping up when i try to close the form
Close();
}
else {
e.Cancel = true;
}
}
Have you tried removing the Close(); call? You're already in a Closing event handler – unless you cancel the close, it's going to happen anyway.
You don't need to add a call to Close method inside FormClosing because you are already in the form close call pattern of Application.
You need to write:
private void AdminPanel_FormClosing(object sender, FormClosingEventArgs e)
{
var result = MessageBox.Show(this,
"Are you sure you want to close the Application?",
"Exit",
MessageBoxButtons.YesNo, MessageBoxIcon.Question) );
if ( result != DialogResult.Yes )
{
e.Cancel = true;
}
}
If DialogResult.Yes then it does nothing to e.Cancel and the form is closed and the FormClosed event is called.
If e.Cancel is set to true then the Close call is cancelled by the Application manager and FormClosed is not called.
If you add a call to Close in FormClosing you will get a stack overflow : the box is shown and shown and shown and shown and shown and so on without end as long as you click on Yes, unless you click on No...
If you want to force the application ending you can use in the FormClosed event:
Environment.Exit(0);
But perhaps you have something somewhere that prevents the close.
Do you have code in FormClosed ? Does it throw an exception ? Else you need to catch it because it stops the close.

Exit my application with Yes No message box

I am using below code to exit my entire application application with YesNo question messagebox my problem is that some times I got the message twice and other times I get it correctly as one message display ..
any one can help me why that happening ??
private void AppClose_Click(object sender, EventArgs e)
{
this.Close();
}
private void F0100_FormClosing(object sender, FormClosingEventArgs e)
{
DialogResult result;
result = MessageBox.Show("Are you sure you want to exit?", "Exit Message", MessageBoxButtons.YesNo, MessageBoxIcon.Question);
if (result == DialogResult.Yes)
{
//Environment.Exit(1);
Application.Exit();
}
else
{ e.Cancel = true; }
}
I am assuming that the form in question is your main form i.e. You launch this Form as Application.Run(new Form1());
If that is the case, typically you don't need to do Application.Exit() under the Yes branch from FormClosing. So your code should be something like below
private void F0100_FormClosing(object sender, FormClosingEventArgs e)
{
if (e.CloseReason != CloseReason.UserClosing)
return;
DialogResult result;
result = MessageBox.Show("Are you sure you want to exit", MessageBoxButtons.YesNo, MessageBoxIcon.Question);
if (result != DialogResult.Yes)
{
e.Cancel = true;
}
}
The superfluous Application.Exit() call, creates an extra FormClosing event
NOTE: You should also check the FormClosingEventArgs.CloseReason so you don't create an extra popup when say user is logging off or killing the process.
Then this answer might help you some. Basically, you need to use the one you commented out: Environment.Exit(0). The Application one is a graceful attempt at exiting that attempts to close forms. Your form is still open, so it receives a 2nd FormClosing call. It's all up to timing, really, but I'd think that most of the time you'd see the prompt twice.

Why when choosing No it's asking twice?

private void Form1_FormClosing(object sender, FormClosingEventArgs e)
{
if (MessageBox.Show("Are you sure you want to exist ?",
"Are you sure you want to exist ?",
MessageBoxButtons.YesNo,
MessageBoxIcon.Information) == DialogResult.No)
{
e.Cancel = true;
Application.Exit();
}
}
If i click Yes it's existing. But if i click No the message is show again and only on the second time the No take effect.
And i have a backgroundworker and a richTextView that i update. e.Cancel = true and application.exit is enough ?
Your logic is not right, you need to do one of those actions and not both depending on what was picked.
private void Form1_FormClosing(object sender, FormClosingEventArgs e)
{
if (MessageBox.Show("Are you sure you want to exit ?",
"Are you sure you want to exit ?",
MessageBoxButtons.YesNo,
MessageBoxIcon.Information) == DialogResult.No)
{
e.Cancel = true; // cancels the close action
}
else
Application.Exit(); // closes the app, this might not be necessary. Just proceeding with the form close is enough UNLESS this is not the main application form
}
If you choose "No", you cancel the current FormClosing event with e.Cancel = true;.
But then you call Application.Exit(); anyway. So the Form gets closed again and FormClosing is raised another time.
Remove the line Application.Exit() and everything should work fine.

Ask the user before closing C# WPF application

I want to ask the user before closing the application.
I'm using C# .NET 4.0 WPF. I can do it in windows forms, but not in WPF.
Event is fired when the user want to close the app. Message box appears, bun no matter which button is pressed (Yes or No) the application always closes. Why? Where is the mistake?
It works, but only when the user presses the "X". When the user presses the close button with Application.Current.Shutdown(); it is not working.
private void MainWindowDialog_Closing(object sender,
System.ComponentModel.CancelEventArgs e)
{
MessageBoxResult result = MessageBox.Show("Do you really want to do that?",
"Warning", MessageBoxButton.YesNo, MessageBoxImage.Question);
if (result == MessageBoxResult.No)
{
e.Cancel = true;
}
}
The Closing event cannot be cancelled if you call Application.Current.Shutdown(). Just call the Window.Close() method instead, which will give you a chance to veto the close operation. Once all your program's windows have closed the application will shutdown automatically.
For more information checkout the Application Management page on MSDN.
Just call YourMainWindow.Close() and use the Closing event as described before.
private void Form1_FormClosing(object sender, FormClosingEventArgs e)
{
if (MessageBox.Show("Are you sure to exit?", "Exit", MessageBoxButtons.YesNo, MessageBoxIcon.Question) == DialogResult.Yes)
e.Cancel = false;
else
e.Cancel = true;
}
Why don't you just ask the user whether he wants to close the application, and then call Application.Current.Shutdown() like this:
private void closeButton_Click(object sender, RoutedEventArgs e)
{
if (MessageBox.Show("Do you want to exit?", "Confirm",
MessageBoxButton.YesNo) == MessageBoxResult.Yes)
{
Application.Current.Shutdown();
}
}

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