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Timer that closes modal form in Windows Forms

I have several modeless Forms with grids to show data in a MDI Windows Forms app (Form1 in example code). Each of these Forms has a button that opens another Form as modal using ShowDialog (Form2 in example code), which allows editing the data shown in Form1. These modal forms have a Cancel button that closes the form without saving changes by setting DialogResult to Cancel.
I want to implement a timer that closes all forms after a certain time has elapsed from user login into the app. The problem arises if the timer triggers while a modal Form is open.
public partial class Form1 :
{ //Constructor ommited for brevity
private void btnEditData_Click(object sender, EventArgs e)
{
var form2 = new Form2();
timer1.Tick += (_, __) =>
{
form2.DialogResult = DialogResult.Cancel;
this.Close(); // this executes before form2.ShowDialog returns
};
timer1.Interval = 5_000;
timer1.Enabled = true;
form2.ShowDialog();
reloadData(); // here Form1 is already disposed because Close
// has been called on it. An exception is thrown as a consequence
}
private void reloadData()
{
if (this.IsDisposed)
// simulate using a disposed form
throw new ObjectDisposedException(this.Name);
}
}
My intention would be to somehow schedule the call Form1.Close() after form2.ShowDialog() has returned and the btnEditData_Click method has finished, so that there would be no danger of using a disposed form.

EDIT
After seeing your code, I'd suggest to introduce a third option in your Tick event handler that would be used to decide if you have to close the form. For example, Abort.
timer1.Tick += (_, __) =>
{
form2.DialogResult = DialogResult.Abort;
};
if (form2.ShowDialog() == DialogResult.Abort) Close();
else reloadData();
First thought: keep it simple and keep it clean. You don't have to keep track of your open forms, in an MDI application there is MdiChildren property of the parent form that will give you all the forms.
Then, to handle the closing part, you can use existing functionalities in .Net.
A difficult approach is using P/Invoke. You load Windows DLLs and use their functions to enumerate through all your forms and close which one you want. You can also simulate a click on Cancel button. You have to start with EnumWindows function (to identify the forms) and EnumChildWindows for form's children. I like this option because you have full control of your forms and controls, but can give you headaches if not familiar with the concept.
You can have a look at FormClosing event and subscribe to it. This event fires before the form is closed and you can make the clean up using it.
Using OOP - inheritance and override. Either you create a base form with custom close function that does the cleaning (and then inherit all your forms through it), or override form's close functions to achieve your goal.

WinForms; detecting form closed from another form

Is it possible to detect a form closing from another form.
For example.
If I had a mainForm that opens subForm, can I detect within the mainForm that the subForm has closed and execute code?
I understand I could create an event handler within the subForm, but this is not really what I'm after because what I'm about to do after the subForm closes, is within the mainForm (changes to mainForm).

The FormClosed event is public, so you can create a handler from the main form.
//Inside main Form. Click button to open new form
private void button1_Click(object sender, EventArgs e)
{
Form2 f2 = new Form2();
f2.FormClosed += F2_FormClosed;
f2.Show();
}
private void F2_FormClosed(object sender, FormClosedEventArgs e)
{
MessageBox.Show("Form was closed");
}

Take a look at the public FormClosedEvent. Since the modifier is public, you're able to do something like the following example:
SubForm subForm = new SubForm();
subForm.FormClosed += delegate
{
MessageBox.Show("subForm has closed");
};
subForm.ShowDialog();
The above example creates a new form (of type SubForm), adds a new event handler to display a message box telling the user that the form has closed, and finally uses the ShowDialog() method which will prevent the user accessing the main form until the sub form has been closed.

The usual case for this is a "Modal Dialog" (like Message Box and its Family).
Every form can be opened as Modal Dialog, by using ShowDialog() isntead of Show().
Otherwise the event way is the only way.

changing the control box on a form when exiting

Ok, I have a question about the Form Controlbox. I was wondering if it is possible to change or add what the exit button does on the form.
I can easily minimize, maximize and exit the form no problem. But this is what I am facing.
My app has an access login. After you log in it comes to the main form. I have a log out button when pressed, it goes back to the login form.
However, if you press the exit button, it exits the main form, and the program is still running, but with no way to bring the login form up.
So what I am trying to do is, when the main form is exited through the red X I want it to go to the login.
I can go the complex route: borderless form, movable form, custom buttons and etc., etc.,
I think it would be easier to change or add the exit button to return to the login form. Is this possible?

Move the logic out of your button click event, into a separate method.
private void button1_Click(object sender, EventArgs e)
{
OverrideFormExit();
}
private void OverrideFormExit()
{
// execute the code that was previously in button1's click event
}
Now you can subscribe that same method to your Form's Closed event, so that it executes when the user closes the Form.
For example, place the following in your Form's constructor:
FormClosed += (s, e) => OverrideFormExit();
Alternatively, you can subscribe to the main Form's Closed event from within the Login Form, when you instantiate the main Form. I'm guessing at what your code looks like here, obviously.
private void ShowMainForm()
{
FormMain frmMain = new FormMain();
frmMain.Show();
frmMain.FormClosed += (s, e) => this.Show();
this.Hide();
}

Properties Window in C#

I'm currently trying to create a Properties Window which is opened after a Button on the Outlook Toolbar is pressed, i now have:
1) the Button on the Toolbar (currently if pressed nothing occurs)
2) i know how to create the method which would hold the action after the Button is Pressed
-but, I am a beginner and i don't know how to create a window which would open after the button is pressed, the Window should be fairly big, and for now have nothing but a checkbox(which i later would like to apply some method to.
if you ever created a window which opens after a button is pressed, i would be really pleased to get your help.
All help is appreciated, thank you

Here's the recommended way of opening a dialog window when the user clicks a button:
Add a new form to your project (e.g. MyForm) and then you can use the following code in your button's click event handler:
private void OnMyButtonClicked(object sender, EventArgs e)
{
MyForm myForm = new MyForm();
if (myForm.ShowDialog() == DialogResult.OK)
{
// The code that should be executed when the dialog was closed
// with an OK dialog result
}
}
In case you do not want the new window to be modal (i.e. you want to allow the user use other parts of the application while the window is opened), the code gets even more simple:
private void OnMyButtonClicked(object sender, EventArgs e)
{
MyForm myForm = new MyForm();
myForm.Show();
}
You can also create your form on the fly without adding one to your project, which is a bit more complicated, but advanced developers prefer this approach instead of messing with the designer ;)
private void OnMyButtonClicked(object sender, EventArgs e)
{
Form myForm = new Form();
myForm.Text = "My Form Title";
// Add a checkbox
CheckBox checkBox = new CheckBox();
checkBox.Text = "Check me";
checkBox.Location = new Point(10, 10);
myForm.Controls.Add(checkBox);
// Show the form
myForm.Show();
}

Here is a small tutorial for you to follow..
http://msdn.microsoft.com/en-us/library/ws1btzy8%28v=vs.90%29.aspx
EDIT: I would also recommend you remember the msdn website because it will prove invaluable for other programming issues you come across..

you have to add a new form to your project. Then you call the constructor where you want to pop up the window.
like this
Form2 form2 = new Form2();
form2.showDialog();
Edit:
where form2 is not the "main" Form of you program.
This'll set your main window to the background as long as the newly popped up window is closed.

To close C# Forms Application

I have 2 forms ...when i start the application..and use the close "X" from the title bar the entire application closes...now when i select an option from the 1st form in my case it is a button "ADD" as its a phonebook application..it goes to the 2nd form as i have used 1stform.hide() and 2ndform.show()...now when i do "X" from the title bar it doesnt shutdown completely as the 1stform is not closed....how to program it in such a way tht any stage the entire application should close

Your first form is set as the startup form. That means whenever it gets closed, your entire application is closed. And conversely, your application does not close until it gets closed. So when you hide the startup form and show the second form, the user closing the second form does not trigger your application closing because they have only closed a secondary, non-modal dialog.
I recommend changing your design so that the startup form is also the main form of your application. No sense trying to work around built-in functionality that can actually be useful. You want the application to quit when the main form is closed, no matter what other child forms are opened.
But the quick-and-dirty solution in your case is to make a call to Application.Exit. That will close all of the currently open forms and quit your application immediately. As I said just above, I don't so much recommend this approach because having to call Application.Exit from every form's FormClosed event handler is a sign that something has gone seriously wrong in your design.
If the single startup form paradigm doesn't work out for you, you should look into taking matters into your own hands and customizing the Main method in your Program.cs source file. See the answers given to this related question for some ideas on how that might work for you.

What you can do is to use the Form's FormClosing event, and add the following code:
Application.Exit();
This will stop the entire application, and close all windows. However, if a background thread is running, the process itself will survive. In this case you can use:
Environment.Exit();

Add a Application.Exit on every forms's Closing event
like this:
Create an closing event handler first
private void Form_ClosingEventhandler()(object sender, CancelEventArgs e)
{
//Perform any processing if required like saving user settings or cleaning resources
Application.Exit();
}
then bind this event to any form you create.
//Where you create new form and show it.
Form1 frm= new Form1();
//set other properties
frm.Closing += new EventHandler(Form_ClosingEventhandler);
Form2 frm2= new Form2();
//set other properties
frm2.Closing += new EventHandler(Form_ClosingEventhandler);

Surely you don't want to shut down the entire application after the user adds a phone number? You just need to make sure that your main window becomes visible again. Write that like this:
private void AddButton_Click(object sender, EventArgs e) {
var frm = new AddPhoneNumber();
frm.StartPosition = FormStartPosition.Manual;
frm.Location = this.Location;
frm.Size = this.Size; // optional
frm.FormClosing += delegate { this.Show(); };
frm.Show();
this.Hide();
}