In MSDN I found CloseReason.UserClosing to know that the user had decided to close the form
but I guess it is the same for both clicking the X button or clicking the close button.
So how can I differentiate between these two in my code?
Thanks all.
Assuming you're asking for WinForms, you may use the FormClosing() event. The event FormClosing() is triggered any time a form is to get closed.
To detect if the user clicked either X or your CloseButton, you may get it through the sender object. Try to cast sender as a Button control, and verify perhaps for its name "CloseButton", for instance.
private void Form1_FormClosing(object sender, FormClosingEventArgs e) {
if (string.Equals((sender as Button).Name, #"CloseButton"))
// Do something proper to CloseButton.
else
// Then assume that X has been clicked and act accordingly.
}
Otherwise, I have never ever needed to differentiate whether X or CloseButton was clicked, as I wanted to perform something specific on the FormClosing event, like closing all MdiChildren before closing the MDIContainerForm, or event checking for unsaved changes. Under these circumstances, we don't need, according to me, to differentiate from either buttons.
Closing by ALT+F4 will also trigger the FormClosing() event, as it sends a message to the Form that says to close. You may cancel the event by setting the
FormClosingEventArgs.Cancel = true.
In our example, this would translate to be
e.Cancel = true.
Notice the difference between the FormClosing() and the FormClosed() events.
FormClosing occurs when the form received the message to be closed, and verify whether it has something to do before it is closed.
FormClosed occurs when the form is actually closed, so after it is closed.
Does this help?
The CloseReason enumeration you found on MSDN is just for the purpose of checking whether the user closed the app, or it was due to a shutdown, or closed by the task manager, etc...
You can do different actions, according to the reason, like:
void Form_FormClosing(object sender, FormClosingEventArgs e)
{
if(e.CloseReason == CloseReason.UserClosing)
// Prompt user to save his data
if(e.CloseReason == CloseReason.WindowsShutDown)
// Autosave and clear up ressources
}
But like you guessed, there is no difference between clicking the x button, or rightclicking the taskbar and clicking 'close', or pressing Alt F4, etc. It all ends up in a CloseReason.UserClosing reason.
The "X" button registers as DialogResult.Cancel so another option is to evaluate the DialogResult.
If you have multiple buttons on your form, you're probably already associating different DialogResults to each and this will provide you with the means to tell the difference between each button.
(Example: btnSubmit.DialogResult = DialogResult.OK, btnClose.DialogResult = Dialogresult.Abort)
public Form1()
{
InitializeComponent();
this.FormClosing += Form1_FormClosing;
}
/// <summary>
/// Override the Close Form event
/// Do something
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void Form1_FormClosing(Object sender, FormClosingEventArgs e)
{
//In case windows is trying to shut down, don't hold the process up
if (e.CloseReason == CloseReason.WindowsShutDown) return;
if (this.DialogResult == DialogResult.Cancel)
{
// Assume that X has been clicked and act accordingly.
// Confirm user wants to close
switch (MessageBox.Show(this, "Are you sure?", "Do you still want ... ?", MessageBoxButtons.YesNo, MessageBoxIcon.Question))
{
//Stay on this form
case DialogResult.No:
e.Cancel = true;
break;
default:
break;
}
}
}
How to detect if the form closed by click on X button or by calling Close() in code?
You cannot rely on close reason of the form closing event args, because:
if the user click X button on title bar or
close the form using Alt + F4 or
use system menu to close the form or
the form get closed by calling Close() method,
for all of above cases, the close reason will be Closed by User (CloseReason.UserClosing), which is not desired result.
To distinguish if the form closed by X button or by Close method, you can use either of the following options:
Handle WM_SYSCOMMAND and check for SC_CLOSE and set a flag.
Check the StackTrace to see if any of the frames contain Close method call.
Example 1 - Handle WM_SYSCOMMAND
public bool ClosedByXButtonOrAltF4 {get; private set;}
private const int SC_CLOSE = 0xF060;
private const int WM_SYSCOMMAND = 0x0112;
protected override void WndProc(ref Message msg)
{
if (msg.Msg == WM_SYSCOMMAND && msg.WParam.ToInt32() == SC_CLOSE)
ClosedByXButtonOrAltF4 = true;
base.WndProc(ref msg);
}
protected override void OnShown(EventArgs e)
{
ClosedByXButtonOrAltF4 = false;
}
protected override void OnFormClosing(FormClosingEventArgs e)
{
if (ClosedByXButtonOrAltF4)
MessageBox.Show("Closed by X or Alt+F4");
else
MessageBox.Show("Closed by calling Close()");
}
Example 2 - Checking StackTrace
protected override void OnFormClosing(FormClosingEventArgs e)
{
if (new StackTrace().GetFrames().Any(x => x.GetMethod().Name == "Close"))
MessageBox.Show("Closed by calling Close()");
else
MessageBox.Show("Closed by X or Alt+F4");
}
It determines when to close the application if a form is closed (if your application is not attached to a specific form).
private void MyForm_FormClosed(object sender, FormClosedEventArgs e)
{
if (Application.OpenForms.Count == 0) Application.Exit();
}
I always use a Form Close method in my applications that catches alt + x from my exit Button, alt + f4 or another form closing event was initiated. All my classes have the class name defined as Private string mstrClsTitle = "grmRexcel" in this case, an Exit method that calls the Form Closing Method and a Form Closing Method. I also have a statement for the Form Closing Method - this.FormClosing = My Form Closing Form Closing method name.
The code for this:
namespace Rexcel_II
{
public partial class frmRexcel : Form
{
private string mstrClsTitle = "frmRexcel";
public frmRexcel()
{
InitializeComponent();
this.FormClosing += frmRexcel_FormClosing;
}
/// <summary>
/// Handles the Button Exit Event executed by the Exit Button Click
/// or Alt + x
///
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void btnExit_Click(object sender, EventArgs e)
{
this.Close();
}
/// <summary>
/// Handles the Form Closing event
///
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void frmRexcel_FormClosing(object sender, FormClosingEventArgs e)
{
// ---- If windows is shutting down,
// ---- I don't want to hold up the process
if (e.CloseReason == CloseReason.WindowsShutDown) return;
{
// ---- Ok, Windows is not shutting down so
// ---- either btnExit or Alt + x or Alt + f4 has been clicked or
// ---- another form closing event was intiated
// *) Confirm user wants to close the application
switch (MessageBox.Show(this,
"Are you sure you want to close the Application?",
mstrClsTitle + ".frmRexcel_FormClosing",
MessageBoxButtons.YesNo, MessageBoxIcon.Question))
{
// ---- *) if No keep the application alive
//---- *) else close the application
case DialogResult.No:
e.Cancel = true;
break;
default:
break;
}
}
}
}
}
You can try adding event handler from design like this: Open form in design view, open properties window or press F4, click event toolbar button to view events on Form object, find FormClosing event in Behavior group, and double click it.
Reference: https://social.msdn.microsoft.com/Forums/vstudio/en-US/9bdee708-db4b-4e46-a99c-99726fa25cfb/how-do-i-add-formclosing-event?forum=csharpgeneral
namespace Test
{
public partial class Member : Form
{
public Member()
{
InitializeComponent();
}
private bool xClicked = true;
private void btnClose_Click(object sender, EventArgs e)
{
xClicked = false;
Close();
}
private void Member_FormClosing(object sender, FormClosingEventArgs e)
{
if (xClicked)
{
// user click the X
}
else
{
// user click the close button
}
}
}
}
if (this.DialogResult == DialogResult.Cancel)
{
}
else
{
switch (e.CloseReason)
{
case CloseReason.UserClosing:
e.Cancel = true;
break;
}
}
if condition will execute when user clicks 'X' or close button on form. The else can be used when user clicks Alt+f4 for any other purpose
I agree with the DialogResult-Solution as the more straight forward one.
In VB.NET however, typecast is required to get the CloseReason-Property
Private Sub MyForm_Closing(sender As Object, e As CancelEventArgs) Handles Me.Closing
Dim eCast As System.Windows.Forms.FormClosingEventArgs
eCast = TryCast(e, System.Windows.Forms.FormClosingEventArgs)
If eCast.CloseReason = Windows.Forms.CloseReason.None Then
MsgBox("Button Pressed")
Else
MsgBox("ALT+F4 or [x] or other reason")
End If
End Sub
I also had to register the closing function inside the form's "InitializeComponent()" method:
private void InitializeComponent() {
// ...
this.FormClosing += FrmMain_FormClosing;
// ...
}
My "FormClosing" function looks similar to the given answer (https://stackoverflow.com/a/2683846/3323790):
private void FrmMain_FormClosing(object sender, FormClosingEventArgs e) {
if (e.CloseReason == CloseReason.UserClosing){
MessageBox.Show("Closed by User", "UserClosing");
}
if (e.CloseReason == CloseReason.WindowsShutDown){
MessageBox.Show("Closed by Windows shutdown", "WindowsShutDown");
}
}
One more thing to mention: There is also a "FormClosed" function which occurs after "FormClosing". To use this function, register it as shown below:
this.FormClosed += MainPage_FormClosed;
private void MainPage_FormClosing(object sender, FormClosingEventArgs e)
{
// your code after the form is closed
}
I've done something like this.
private void Form_FormClosing(object sender, FormClosingEventArgs e)
{
if ((sender as Form).ActiveControl is Button)
{
//CloseButton
}
else
{
//The X has been clicked
}
}
Related
I have a Log In form and I need to know if user pressed the X button on form or the button that takes him to the new form. If user closed the program with Alt+F4 or X button the program must be closed.
I was trying with FormClosing event to check whether user pressed X or login.
private void LogIn_FormClosing(object sender, FormClosingEventArgs e)
{
if (string.Equals((sender as Button).Name, #"loginButton"))
{
//some code
}
else
{
Close();
}
}
The FormClosing event handler receives a FormClosingEventArgs argument that contains the property CloseReason, but in your context this is not enough.
Indeed, in both cases (ALT+F4/X-Click or ButtonClick) the argument will contain a CloseReason equal to UserClosing.
I suggest you a simple workaround. In your button click handler (where you should call the close action on the form, not on the formclosing event handler itself), add something to the Tag property of the form like so:
private void Button1_Click(object sender, EventArgs e)
{
this.Tag = "ClosedByUser";
this.Close();
}
now in the FormClosing event handler is simple to check this property
private void LogIn_FormClosing(object sender, FormClosingEventArgs e)
{
if (this.Tag != null)
{
// Button clicked
}
else
{
// other reasons
// Dp not call Close here, you are already closing
// if you don't set e.Cancel = true;
}
}
I have a "Quit" button that changes text based on a variable. When clicked, the variable increases by one, and the application quits when the var is 2.
public static int QuitVar = 0;
private void quitToolStripMenuItem_Click(object sender, EventArgs e)
{
QuitVar = QuitVar + 1;
if (QuitVar == 0)
{
quitToolStripMenuItem.Text = "Quit";
}
if (QuitVar == 1)
{
quitToolStripMenuItem.Text = "Really?";
}
if (QuitVar == 2)
{
QuitVar = 0;
Application.Exit();
}
I would like QuitVar to change back to 0 when the user clicks outside the button, so the button text is "quit". Is there a way to do this in C#?
There are too many places a user could click that aren't the Quit button. What might be easier is to detect when the mouse leaves the Quit button with the MouseLeave event.
By going to the Control properties (I used a Button here), and Events (the lighting symbol), then double-clicking inside the MouseLeave event, it will generate a template event handler method for you:
Inside that event handler, set your text and QuitVar appropriately:
private void quitToolStripMenuItem_MouseLeave(object sender, EventArgs e)
{
QuitVar = 0;
quitToolStripMenuItem.Text = "Quit";
}
You could try creating a custom ToolstripMenuItem, and override the WndProc Method.
The override can capture the windows messages, and notify when the click is not on the item. The following code is adapted from code to close a form if the user clicks outside it, but it should suit your purposes.
/// <summary>
/// Function to capture if the user clicks outside of the control, in which case need to close this form.
/// </summary>
protected override void WndProc(ref Message m)
{
base.WndProc(ref m);
// if click outside dialog -> Close Dlg
if (m.Msg == 0x86) //0x86 = NativeConstants.WM_NCACTIVATE
{
if (this.Visible)
{
if (!this.RectangleToScreen(this.DisplayRectangle).Contains(Cursor.Position))
QuitVar = 0;
}
}
}
My program makes some changes in the registry while it's running, and if they are not properly rolled back, they might cause the user some problems. FOr example, they might not be able to use their Internet connection.
So I need to make sure that when they close the application, I return everything back to normal. To do this, I need to know when they have pressed the Close button of the form. How can I do that? Is there an event that I can handle?
There is an event you can subscribe to called FormClosing this fire before FormClose and allows you to validate/change the settings you need before the form closes
public Form1()
{
InitializeComponent();
FormClosing += Form1_FormClosing;
}
void Form1_FormClosing(object sender, FormClosingEventArgs e)
{
// Reset values
}
I think that what you need is not access to the close button, but rather access to the event which is fired when the form is closed.
Taken from this previous SO post, what you might need is something like so:
void FormClosed(object sender, FormClosedEventArgs e)
{
// do something useful
}
There are more possibilites here.
1) Use the FormClosing event of the form:
private void form_FormClosing(object sender, FormClosingEventArgs e) {
if (e.CloseReason == CloseReason.UserClosing) { // User clicked 'X' button
if (someThing) e.Cancel = true; // Disable Form closing
}
}
2) You can also hide the 'X' button by set ControlBoxto false. But this will also hide the minimize and maximize buttons.
3) This disables only the 'X' button. Place it in your form.
private const int CP_NOCLOSE_BUTTON = 0x200;
protected override CreateParams CreateParams {
get {
new SecurityPermission(SecurityPermissionFlag.UnmanagedCode).Demand();
CreateParams cp = base.CreateParams;
cp.ClassStyle |= CP_NOCLOSE_BUTTON;
return cp;
}
}
I have a form which contains a close button (there are many control in the form, but I am concerning about the close event) and a save button.
If a form have value in certain text box (say TextBox1),
Then I want to validate that the save button is clicked before closing the form (whether close button or the 'X' button at top is pressed).
But if there is no value in that text box or the form is just initialized and user just want to close the form, it simply closes the form. How to perform this validation.
I would follow the pattern of 99% of windows applications: allow to close a window, but ask to save changes if there are any. Here is a simple implementation of that pattern:
private bool _hasChanges;
private void textBox1_TextChanged(object sender, EventArgs e)
{
this._hasChanges = true;
}
private void form_FormClosing(object sender, FormClosingEventArgs e)
{
if (this._hasChanges)
{
var dialogResult = MessageBox.Show("Save changes?", "Confirm", MessageBoxButtons.YesNoCancel);
switch (dialogResult)
{
case DialogResult.Yes:
this.Save();
break;
case DialogResult.No:
this._hasChanges = false;
break;
}
e.Cancel = this._hasChanges;
}
}
private void Save()
{
// Save
this._hasChanges = false;
}
private void buttonSave_Click(object sender, EventArgs e)
{
this.Save();
}
private void buttonOk_Click(object sender, EventArgs e)
{
this.Close();
}
private void buttonCancel_Click(object sender, EventArgs e)
{
this._hasChanges = false;
this.Close();
}
The pivotal part is the boolean _hasChanges. If there are many controls that can cause changes this can be real pain. An alternative could be to use databinding to a class that implements INotifyPropertyChanged and subscribe to its PropertyChanged event.
Tie into the Closing Event and use your EventHandler to validate that textbox. Keep in mind that Closing occurs at the time the form is closing and (if memory servers correctly) there is a property on the eventarg that will let you cancel closing of the form. This event is raised regardless of how the request is executed.
I have a dialog that I show with <class>.ShowDialog(). It has an OK button and a Cancel button; the OK button also has an event handler.
I want to do some input validation in the event handler and, if it fails, notify the user with a message box and prevent the dialog from closing. I don't know how to do the last part (preventing the close).
You can cancel closing by setting the Form's DialogResult to DialogResult.None.
An example where button1 is the AcceptButton:
private void button1_Click(object sender, EventArgs e) {
if (!validate())
this.DialogResult = DialogResult.None;
}
When the user clicks button1 and the validate method returns false, the form will not be closed.
Given that you've specified you want a pop error dialog, one way of doing this is to move your validation into a OnClosing event handler. In this example the form close is a aborted if the user answers yes to the question in the dialog.
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...
}
}
}
By setting e.Cancel = true you will prevent the form from closing.
However, it would be a better design/user experience to display the validation errors inline (via highlighting the offending fields in some way, displaying tooltips, etc.) and prevent the user from selecting the OK button in the first place.
Don't use the FormClosing event for this, you'll want to allow the user to dismiss the dialog with either Cancel or clicking the X. Simply implement the OK button's Click event handler and don't close until you are happy:
private void btnOk_Click(object sender, EventArgs e) {
if (ValidateControls())
this.DialogResult = DialogResult.OK;
}
Where "ValidateControls" is your validation logic. Return false if there's something wrong.
You can catch FormClosing an there force the form to remain opened.
use the Cancel property of the event argument object for that.
e.Cancel = true;
and it should stop your form from closing.
This doesn't directly answer your question (other already have), but from a usability point of view, I would prefer the offending button be disabled while the input is not valid.
Use this code:
private void btnOk_Click(object sender, EventArgs e) {
if (ValidateControls())
this.DialogResult = DialogResult.OK;
}
The problem of it is that the user has to clic two times the buttons for closing the forms;
Just add one line in the event function
private: System::Void button1_Click(System::Object^ sender, System::EventArgs^ e)
{
this->DialogResult = System::Windows::Forms::DialogResult::None;
}
I wish I had time to find a better example, but you would be much better off using the existing windows forms validation techniques to do this.
http://msdn.microsoft.com/en-us/library/ms229603.aspx
void SaveInfo()
{
blnCanCloseForm = false;
Vosol[] vs = getAdd2DBVosol();
if (DGError.RowCount > 0)
return;
Thread myThread = new Thread(() =>
{
this.Invoke((MethodInvoker)delegate {
picLoad.Visible = true;
lblProcces.Text = "Saving ...";
});
int intError = setAdd2DBVsosol(vs);
Action action = (() =>
{
if (intError > 0)
{
objVosolError = objVosolError.Where(c => c != null).ToArray();
DGError.DataSource = objVosolError;// dtErrorDup.DefaultView;
DGError.Refresh();
DGError.Show();
lblMSG.Text = "Check Errors...";
}
else
{
MessageBox.Show("Saved All Records...");
blnCanCloseForm = true;
this.DialogResult = DialogResult.OK;
this.Close();
}
});
this.Invoke((MethodInvoker)delegate {
picLoad.Visible = false;
lblProcces.Text = "";
});
this.BeginInvoke(action);
});
myThread.Start();
}
void frmExcellImportInfo_FormClosing(object s, FormClosingEventArgs e)
{
if (!blnCanCloseForm)
e.Cancel = true;
}
You can probably check the form before the users hits the OK button. If that's not an option, then open a message box saying something is wrong and re-open the form with the previous state.