Properly Closing Secondary Form VS Application Exit - c#

This is probably going to be a standard question. I have read lots of articles on this but none point out the issue i am having specifically.
I am developing a WinForm and have a "Main Menu" form that is loaded on startup. Within this main are several buttons which open up individual modules (other forms) of the program.
I can open up the form no problem and can close it and re-show the main form no problem. The problem lies when a user hits the (X) in the control box, the application doesnt exit because the main form is still there, but hidden. I know that i could put an application.exit() in the close event of the form. However, then if i have a button that closes the form and wants to unhide the main form, the application will close due to the formclosing event.
Can someone help me understand this principle. I dont think it should be as hard as it seems to me and i dont really want to use Panels.
Thanks in advance.
-Joseph
the following code solved the issue based on the answer provided below
private void btnHome_Click(object sender, EventArgs e)
{
Form f1 = Application.OpenForms[0];
f1.Visible=true;
this.Close();
}
private void frmCostControlMain_FormClosed(object sender, FormClosedEventArgs e)
{
Form f = Application.OpenForms[0]; // The main form
if (f.Visible==true)
{
f.BringToFront();
}
else
{
Application.Exit();
}
}

You can check the Application.OpenForms and see whether some non-hidden forms other than the current form are around. If you only want to check the main form, you can check Application.OpenForms[0]. Since it was opened first, it will always be at index 0. From memory:
Form_Closed(object sender, EventArgs e)
{
Form f = Application.OpenForms[0]; // The main form
if (f.Visible) {
f.BringToFront();
} else {
Application.Exit();
}
}
When the close button is clicked you would first unhide the main form and then close the current form.

I still don't understand your question, but I guess you could use the
Application.Exit().
You should then check the arguments of your FormClosed event.
The Close reason is as follows:
Click on [X]:
CloseReason = UserClosing
Application Exit:
CloseReason = ApplicationExitCall
You could then handle it properly
private void Form1_FormClosed(object sender, FormClosedEventArgs e)
{
if (e.CloseReason == CloseReason.ApplicationExitCall)
{
//Application.Exit();
}
else if (e.CloseReason == CloseReason.UserClosing)
{
//[X] was pressed
}
else
{
//Many other reasons
}
}
I guess there is a much cleaner way of handling your problem. If you provide a bit more details, I think someone would be able to help you along.

Related

How to close C# process?

I wrote a simple program using Visual Studio(C#). When I close my program(click at Х) the form is closed, but the process remains. I had to close it from Task Manager.
What is the command to close process?
My code:
private void Form1_FormClosing(object sender, FormClosingEventArgs e)
{
e.Cancel = true;
}
e.Cancel = true; means stop the form from closing. That's the main issue with your code.
You should use this parameter if you have a confirmation something like "Are you sure you want to close?" if the user selects "No" you set e.Cancel to true.
Just remove that code (or set Cancel to false) and your form will close, and if that's the last one of your application, it will end.
So the final solution for your problem is a simple
private void Form1_FormClosing(object sender, FormClosingEventArgs e)
{
}
The e.Cancel=true will prevent your form from closing, so remove it.
if it still doesn't work, try this :
use the Application.Exit() method on the FormClosed event instead of FormClosing:
To do this, go into your form designer window : press maj + F7 or right click on your form in your solution explorer and click on Form designer (something like that)
Right Click on your Form, Select Properties, display the Events, then double-click on the Form Closed event and the designer will automaticaly register the event and generate your code.
You should have something like this without the Application.Exit() method generated :
private void Form1_FormClosed(object sender, FormClosingEventArgs e)
{
Application.Exit();
}

Minimize form to system tray

I want to hide my form while keeping my application running in background.
I've used notifyIcon and it remains always visible.
I've used "this.Hide();" to hide my form but unfortunately my application gets close (no exception).
I am also using threading and this form is on second thread.
Please tell me how can I solve it.
I am also using threading and this form is on second thread.
My crystal ball says that you've used ShowDialog() to show the form. Yes, calling Hide() on a modal dialog will close it. Necessarily so, a modal dialog normally disables all of the windows in the application. If you hide it then there's no way for the user to get back to the program, there are no windows left to activate. That this form runs on another thread otherwise doesn't factor into the behavior.
You'll need to call Application.Run(new SomeForm()) to avoid this. Now it isn't modal and you can hide it without trouble. But really, do avoid showing forms on non-UI threads. There's no reason for it, your main thread is already quite capable.
add the following event handlers for form resize and notify icon click event
private void Form_Resize(object sender, EventArgs e)
{
if (WindowState == FormWindowState.Minimized)
{
this.Hide();
}
}
private void notifyIcon_Click(object sender, EventArgs e)
{
this.Show();
this.WindowState = FormWindowState.Normal;
}
but this is not close you application

System Tray Icon

Okay firstly I just started C# so I'm not exactly the most skilled programmer out there. Okay so here's my problem that may seem stupid to you guys ;)
I have a simple enough app that a friend asked me to do. So far I have managed with a bit of Google but I'm stuck with this. The app runs fine and minimizes to the system tray and maximizes from the system tray which is good. However, when I open a second form from that application it creates another icon in the system tray and starts duplicating every time I open another form. So eventually I have lots of icons and all of them are seperate instances of the main form. System Tray events
private void notifyIcon_systemTray_MouseDoubleClick(object sender, MouseEventArgs e)
{
if (FormWindowState.Minimized == WindowState)
{
Show();
WindowState = FormWindowState.Normal;
}
}
private void CronNecessityForm_Resize(object sender, EventArgs e)
{
notifyIcon_systemTray.Visible = true;
if (FormWindowState.Minimized == WindowState)
Hide();
}
private void restoreContextMenuItem_Click(object sender, EventArgs e)
{
Show();
WindowState = FormWindowState.Normal;
}
To open the Form:
private void preferencesToolStripMenuItem_Click(object sender, EventArgs e)
{
CronPreferences.formPreferences CronPreferences = new CronPreferences.formPreferences();
CronPreferences.Show();
}
Close it:
private void button2_Click(object sender, EventArgs e)
{
this.Hide();
}
How can I have all Forms map to the same icon in the System Tray?
You will need a single global tray icon that they all access. Do this by using a static variable that stays the same throughout different instances of the class.
Then, if you want to:
Open one form: keep a reference to the latest form in a variable and open it.
Open all minimised forms: iterate through each form and open them again.
If I got it right, you want to keep only a single instance of your application running. In that case, your title is a bit misleading since your problem has nothing to do with tray icons or multiple forms.
Code Project: A Single Instance Application which Minimizes to the System Tray when Closed
On the other hand, if you really have a main form in your app, which opens the second form (which creates a tray icon), in that case you simply need to make sure your second form is instantiated only once:
public class MainForm
{
private SecondForm _secondForm;
public void OpenSecondForm()
{
// create it only once
if (_secondForm == null)
_secondForm = new SecondForm();
// otherwise just show it
_secondForm.Show();
}
}

Exit all forms when one close

Hey.
When I say close, I do not speak of the method close(), but when a user hits the close button to the window. I have multiple forms, that show and hide depending on if the user is logged in or about to log in and so on. When the user finaly close one of the forms, I want them all to just exit. Now, when a user closes a form, the program is still running because there is a form in the background hiding.
How can I exit on close, I remember doing this in Java, thanks.
Call the Application.Exit() method.
private void btnExit_Click(object sender, EventArgs e)
{
for (int i = Application.OpenForms.Count - 1; i >= 0; i--)
{
if (Application.OpenForms[i].Name != "Menu")
Application.OpenForms[i].Close();
}
}
Call the Environment.Exit(0); method
private void btnExit_Click(object sender, EventArgs e)
{
Environment.Exit(0);
}
Only call Application.Exit() if you know, that the rest of the application can close ungracefully. If other open forms need to do something in their FormClosing event, this wont get done. Using Application.Exit() is a "bad code smell" meaning that there is something wrong with your design.
Do centralized event handling that all forms subsribe to, so they can be notified when the application is closing. There are also plenty of other ways to handle this, Teh Googles knows :)
I tried solve same problem and this is working fine:
private void Form2_FormClosed(object sender, FormClosedEventArgs e)
{
Application.Exit();
}

How to Disable Alt + F4 closing form?

What is the best way to disable Alt + F4 in a c# win form to prevent the user from closing the form?
I am using a form as a popup dialog to display a progress bar and I do not want the user to be able to close it.
This does the job:
private void Form1_FormClosing(object sender, FormClosingEventArgs e)
{
e.Cancel = true;
}
Edit: In response to pix0rs concern - yes you are correct that you will not be able to programatically close the app. However, you can simply remove the event handler for the form_closing event before closing the form:
this.FormClosing -= new System.Windows.Forms.FormClosingEventHandler(this.Form1_FormClosing);
this.Close();
If you look at the value of FormClosingEventArgs e.CloseReason, it will tell you why the form is being closed. You can then decide what to do, the possible values are:
Member name - Description
None - The cause of the closure was not defined or could not be determined.
WindowsShutDown - The operating system is closing all applications before shutting down.
MdiFormClosing - The parent form of this multiple document interface (MDI) form is closing.
UserClosing - The user is closing the form through the user interface (UI), for example by clicking the Close button on the form window, selecting Close from the window's control menu, or pressing ALT+F4.
TaskManagerClosing - The Microsoft Windows Task Manager is closing the application.
FormOwnerClosing - The owner form is closing.
ApplicationExitCall - The Exit method of the Application class was invoked.
I believe this is the right way to do it:
protected override void OnFormClosing(FormClosingEventArgs e)
{
switch (e.CloseReason)
{
case CloseReason.UserClosing:
e.Cancel = true;
break;
}
base.OnFormClosing(e);
}
Note that it is considered bad form for an application to completely prevent itself from closing. You should check the event arguments for the Closing event to determine how and why your application was asked to close. If it is because of a Windows shutdown, you should not prevent the close from happening.
You could handle the FormClosing event and set FormClosingEventArgs.Cancel to true.
I am using a form as a popup dialog to display a progress bar and I do not want the user to be able to close it.
If the user is determined to close your app (and knowledgeable) enough to press alt+f4, they'll most likely also be knowledgeable enough to run task manager and kill your application instead.
At least with alt+f4 your app can do a graceful shutdown, rather than just making people kill it. From experience, people killing your app means corrupt config files, broken databases, half-finished tasks that you can't resume, and many other painful things.
At least prompt them with 'are you sure' rather than flat out preventing it.
This is a hack to disable Alt + F4.
private void test_FormClosing(object sender, FormClosingEventArgs e)
{
if (this.ModifierKeys == Keys.Alt || this.ModifierKeys == Keys.F4)
{
e.Cancel = true;
}
}
Subscribe FormClosing event
private void Form1_FormClosing(object sender, FormClosingEventArgs e)
{
e.Cancel = e.CloseReason == CloseReason.UserClosing;
}
Only one line in the method body.
This does the job:
bool myButtonWasClicked = false;
private void Exit_Click(object sender, EventArgs e)
{
myButtonWasClicked = true;
Application.Exit();
}
private void Form1_FormClosing(object sender, FormClosingEventArgs e)
{
if (myButtonWasClicked)
{
e.Cancel = false;
}
else
{
e.Cancel = true;
}
}
Would FormClosing be called even when you're programatically closing the window? If so, you'd probably want to add some code to allow the form to be closed when you're finished with it (instead of always canceling the operation)
Hide close button on form by using the following in constructor of the form:
this.ControlBox = false;

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