If the user wants to exit the application by clicking on the exit icon or by ALT+F4, I'd like to make a dialog box questioning the user if he/she is really sure about exiting.
How do I capture this event before the application is actually closed?
Check out the OnClosing event for the form.
Here is an extract from that link actually checks for a change on a text field and prompts a save:
private void Form1_Closing(object sender, System.ComponentModel.CancelEventArgs e)
{
// Determine if text has changed in the textbox by comparing to original text.
if (textBox1.Text != strMyOriginalText)
{
// Display a MsgBox asking the user to save changes or abort.
if(MessageBox.Show("Do you want to save changes to your text?", "My Application",
MessageBoxButtons.YesNo) == DialogResult.Yes)
{
// Cancel the Closing event from closing the form.
e.Cancel = true;
// Call method to save file...
}
}
}
You can change the text to suit your needs, and then also I think you might want to switch the DialogResult.Yes to DialogResult.No based on your text.
Here is some modified code just for you:
private void Form1_Closing(object sender, System.ComponentModel.CancelEventArgs e)
{
if(MessageBox.Show("Are you sure you want to quit?", "My Application", MessageBoxButtons.YesNo) == DialogResult.No)
{
e.Cancel = true;
}
}
You should subscribe to the Form_Closing event
Post a dialog box there, and if user abort the closing set the FormCloseEventArgs.Cancel to true.
For example in the Form_Load or using the designer, subscribe the event
Form1.FormClosing += new FormClosingEventHandler(Form1_Closing);
....
private void Form1_FormClosing(Object sender, FormClosingEventArgs e)
{
DialogResult d = MessageBox.Show("Confirm closing", "AppTitle", MessageBoxButtons.YesNo );
if(d == DialogResult.No)
e.Cancel = true;
}
Depending on the situation is not always a good thing to annoy the user with this kind of processing.
If you have valuable modified data and don't want the risk to loose the changes, then it is always a good thing to do, but if you use this only as a confirm of the close action then it's better to do nothing.
You can handle the Form_Closing or Form_Closed events for this.
In Visual Studio click the lightning bolt icon and scroll down to these events in the form properties list. Double click on the one you want and it will hook up the event for you.
Read msdn sample: http://msdn.microsoft.com/en-us/library/system.windows.forms.form.closing.aspx
Is this just one form? If so, you might want to use the FormClosing event, which allows you to cancel it (show the dialog, then set CancelEventArgs.Cancel to true if the user chooses to cancel closing).
If you're talking about windows forms, should be enough to catch your MainWindow's
FormClosing event and in case you want prevent closing, just set the argument of the event handler got fired, to true.
Example:
private void Form1_Closing(object sender, System.ComponentModel.CancelEventArgs e)
{
if(MessageBox.Show("Do you really want to exit?", "My Application",
MessageBoxButtons.YesNo) == DialogResult.No){
// SET TO TRUE, SO CLOSING OF THE MAIN FORM,
// SO THE APP ITSELF IS BLOCKED
e.Cancel = true;
}
}
}
Related
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.
I would like to ask the user when he/she clicks the closebutton: save the file, discard the changes, or go back IF the RichTextBox content changed. Like Windows Notepad or any other text editor does. How could I do that?
You need to read about events and how they work. In this case, you are interested in the TextChanged event of the RichTextBox and the FormClosing event of the form.
TextChanged Event : MSDN
The TextChanged event is raised whenever the contents of the textbox are modified. One way to track changes in the textbox is simply to use a boolean value. Be sure to set it to false when you are loading data into the textbox. Then, when the user changes the text the TextChanged event will fire and you can set the _textChanged (in the example below) value to true.
Similarly, making use of the FormClosing event allows you to react to a user attempting to close the form.
FormClosing Event : MSDN
This event passes a FormClosingEventArgs value e that allows you to cancel the closing of the form (in this case if the user selects to cancel when prompted about the text having been changed). It also allows you to perform any other action before the form is closed.
To create the message dialog you can use an appropriate overload of MessageBox.Show - this function returns a DialogResult indicating which of the buttons the user clicked. This allows you to take different actions depending on the selection the user made.
MessageBox.Show : MSDN
If you don't know how to connect these events, then I suggest you read through some of the basic documentation and examples. This is pretty elementary stuff that you will need to understand to get much of anything done in C#. The examples here are winforms since you have not indicated otherwise.
This is a trivial example :
public partial class Form1 : Form
{
private bool _textChanged;
public Form1()
{
InitializeComponent();
// load data to richtextbox, then ....
_textChanged = false;
}
private void richTextBox1_TextChanged(object sender, EventArgs e)
{
_textChanged = true;
}
private void Form1_FormClosing(object sender, FormClosingEventArgs e)
{
if (_textChanged)
{
DialogResult rslt = MessageBox.Show("save changes?", "some caption",
MessageBoxButtons.YesNoCancel);
if (rslt == DialogResult.Yes)
{
// save changes and exit
}
else if (rslt == DialogResult.Cancel)
{
e.Cancel = true;
// cancel close, return to form
}
// else do not save and continue closing form
}
}
}
I have this event in a new Form:
private void CrawlLocaly_FormClosed(object sender, FormClosedEventArgs e)
{
}
Im not sure if to use Closed or Closing.
The reason is that i want to check if the user shut down the program for example by just closing the application from the taskbar.
If he did close it from the taskbar mouse right click then close then i want it to close all the program and not only this Form.
How can i do it ?
Application.Exit();
Will shut down your application.
Im not really sure if you can detect if he closed it via rightmouse menu. As far as I know you can only see the reasons provided in the FormClosedEventArgs. FormClosing will provide you with same reasons.
Use this event:
private void Form_FormClosing(object sender, FormClosingEventArgs e)
{
if(e.CloseReason == CloseReason.UserClosing)
{
//close forms
Application.Exit();
}
}
There is no way to check whether user closed your form by clicking 'X' or through TaskBar or any other way as the result of CloseReason will always be CloseReason.UserClosing
Well I Stick with such issue also.
In mine app I have 2 forms, #1 main, #2 - for settings - if user close it i want to know save settings or not. Also if settings are null - close app not only form, if user click button save - I want to close (hide) #2 form.
So where is my solution we set tag value to 1 if click button save, so we will know "who" try to close form:
Predefined:
btnSave.Tag = 0;
On save button click event:
btnSave.Tag = 1;
this.Hide();
its will trigger onclose event:
private void frmLogin_FormClosing(object sender, FormClosingEventArgs e)
{
if (btnSave.Tag.ToString() == "0")
{
DialogResult dlg = MessageBox.Show("Do you want to exit without finished setup connection?", "Form", MessageBoxButtons.YesNo, MessageBoxIcon.Information);
if (dlg == DialogResult.No)
{
e.Cancel = true;
}
else
{
e.Cancel = false;
this.Dispose();
Application.Exit();
}
}
else
{
this.Hide();
}
}
I'm trying to implement some code that asks if the user wants to exit the application I've made.
It's in c# and is a windows form application.
I've had very little sleep this week and can't seem to get my head around the onFormClosing event. Could some please give me the exact code I should use to have code executed when the user clicks on the close button (the 'x' in the top right).
Please find it in your heart to help a sleep deprived moron.
Double-click the form's FormClosed event in the events tab of the Properties window in the designer.
The FormClosing event allows you to prevent the form from closing by setting e.Cancel = true.
Well, the event is called FormClosing and is cancellable. Subscribe to it, do your stuff and let the user close their form. This event is fired if the "x" button is used or if you close the form yourself.
You can subscribe to it in the designer by highlighting the form and looking in the events tab of the properties window, as SLaks says, then double-click it. You don't need to do anything special to cope with the "x" button.
The easiest way is to activate the form in the designer and find the event FormClosing in the properties windows and then just double click the event.
Then just do the following:
private void Form1_FormClosing(object sender, FormClosingEventArgs e)
{
if (e.CloseReason == CloseReason.UserClosing)
{
var result = MessageBox.Show("Are you sure you want to exit?", "Exit", MessageBoxButtons.YesNo);
if (result != System.Windows.Forms.DialogResult.Yes)
{
e.Cancel = true;
}
}
}
If you do not specify that the reason has to be UserClosing, it will stop windows from shutting down if you do not exit the program first which is not a good practice.
public Form1()
{
InitializeComponent();
this.FormClosing += new FormClosingEventHandler(Form1_FormClosing);
}
void Form1_FormClosing(object sender, FormClosingEventArgs e)
{
if (MessageBox.Show("Are you sure that you wan't to close this app", "Question", MessageBoxButtons.OKCancel) == DialogResult.Cancel)
e.Cancel = true;
}
I hope this helps
You can add event handler manually. Example to add event handler in constructor:
public frmMain()
{
InitializeComponent();
FormClosing += frmMain_FormClosing;
}
private void frmMain_FormClosing(object sender, FormClosingEventArgs e)
{
//your code
}
Make derive your form fromf the System.Windows.Forms.Form and put this override:
protected override void OnFormClosing(CancelEventArgs e)
{
if (bWrongClose)
{
bWrongClose = false;
e.Cancel = true; // this blocks the `Form` from closing
}
base.OnFormClosing(e);
}
In Visual C#, how can I detect if the user clicks the X button to close the program? I want to ask the user if they'd like to perform a certain action before exiting. I have an exit button in my program itself, and I know I can code it as follows:
private void exitToolStripMenuItem_Click(object sender, EventArgs e)
{
DialogResult result;
if (logfiletextbox.Text != "")
{
result = MessageBox.Show("Would you like to save the current logfile?", "Save?", MessageBoxButtons.YesNo, MessageBoxIcon.Asterisk);
if (result == DialogResult.Yes)
{
savelog.PerformClick();
}
}
Environment.Exit(0); //exit program
}
But how can I do this for the X button that is already built into the program?
private void Form1_FormClosing(object sender, FormClosingEventArgs e)
{
if (MessageBox.Show("cancel?", "a good question", MessageBoxButtons.YesNo) == DialogResult.Yes)
{
e.Cancel = true;
}
}
It's the "FormClosing" - event of the form. Have fun, friend.
Add an event handler for FormClosing on the form.
The Form designer will do this for you automatically if you select the event, but to do it manually:
this.FormClosing += new System.Windows.Forms.FormClosingEventHandler(this.Main_FormClosing);
And then add the handler into your code:
private void Main_FormClosing(object sender, FormClosingEventArgs e)
{
//Code here
}
If you don't want to close the form then you can set:
e.Cancel = true;
There is a FormClosing event you can bind to that gets fired when the form is about to close. The event handler includes a link to the reason the form is closing (user action, OS shutdown, etc), and offers you an option to cancel it.
Check out the MSDN article here: http://msdn.microsoft.com/en-us/library/system.windows.forms.form.formclosing.aspx
use the Application.Exit or Form.Closing event. Exit won't let you cancel, so Closing is probably a better choice
Just use FormClosing event of form
If you're using a form, you can catch the Form.FormClosing event.
It can be cancelled by setting the Cancel property in the args, based on user input.