How to close current form Winform C# - c#

I've got an MDIParent and I've opened a child window. I need to close the current parent if button is clicked. So I've tried the code below
private void button_log_Click(object sender, EventArgs e)
{
MDIParent_Main obj = new MDIParent_Main(textBox_username.Text);
obj.Show();
this.Close();
}
The problem is it's closing both MDIParent_Main and child form.
Where is my error?

The problem you have is that your MDIParent form is the main application form. When you close it the application is ending and taking the child windows with it see this question for more details.
Once of the wildly accepted solutions is to hide the parent form until the child is also closed. Once the child is closed you can close the parent.
// code taken from referenced question
private void btnOpenForm_Click(object sender, EventArgs e)
{
Form2 frm2 = new Form2();
frm2.FormClosed += new FormClosedEventHandler(frm2_FormClosed);
frm2.Show();
this.Hide();
}
private void frm2_FormClosed(object sender, FormClosedEventArgs e)
{
this.Close();
}

you can not do that in that way.
you must first open the mdipather, than show() the login form, than close the login form when autenticaded

Related

Multiple Form GUI application C#

I am creating a C# application . I am new to .NET programming. It's basically a big Windows Forms Application which displays various forms, all interlinked with each other based on user control. My main form is login page to validate the user to go to the Menu Form(second form), where there are options for the user to decide. So the main activity starts from the Menu Form(second form), it contains a label holding the username. From the Menu Form(second form), it goes to the third form which is a pop-up form, which leads to the fourth form. Basically, hide the second form when moving to each form. Now from the fourth form, I want to go back to Menu Form(second form) without creating a new instance. I tried to do this without new instances but no luck. See code below:
Second form (Menu):
private void button_Click(object sender, EventArgs e)
{
PopUp form3 = new Popup();
form3.Show();
// Hides the Menu Form(second form)
this.Hide();
}
Third Form:
private void button_Click(object sender, EventArgs e)
{
var menu = new Menu();
menu.Hide();
// Hide Form #3
Hide();
form4.Show();
// Hide Form #3
Close();
}
Fourth Form:
private void button_Click(object sender, EventArgs e)
{
if(grpSaved == false)
{
Form5 form5 = new Form5();
form5.Show();
form5.FormClosed += new FormClosedEventHandler(unsaved_FormClosed);
grpSaved = true;
}
else
{
var menu = new Menu();
Close();//closes fourth form
menu.Show();
}
}
This code creates a new instance of the Menu Form(second form). Please help me to get around this problem.
While on the second form (Your main form) if you select a button or click a check box to access the third and fourth forms, try using a show dialog cod instead for the new form and then place you this.Show(); after the show dialog to ensure that when the form you opened is closed it will return you to the form you opened it from.
Example:
Instead of:
PopUp form3 = new Popup();
form3.Show();
//hides the second (Menu) form
this.Hide();
Try:
//Hide the second form
this.Hide();
//Bring up your PopUp form
using (PopUp form3 = new PopUp())
form3.ShowDialog();
//When your PopUp form closes the code should continue and show the second form again.
this.Show();
So to stack the forms try the following:
//Menu Form
private void button_Click(object sender, EventArgs e)
{
this.Hide();
using(PopUp form3 = new Popup())
form3.ShowDialog();
this.Show();
}
//PopUp Form
private void button_Click(object sender, EventArgs e)
{
this.Hide();
using(Task form4 = new Task())
form4.ShowDialog();
this.Close();
}
//Task Form
private void button_Click(object sender, EventArgs e)
{
this.Close();
}
The last button only needs to close the task form. Once it closes the code on the PopUp form will continue which will close the PopUp form and return you to your original Menu form without loading a new form, and clearing the form stack in the process.
It's a clean solution except that it does not inherently save the data from the other two forms. Clicking on the button on the Menu page again will bring up a new PopUp form.

Hiding Form 1 and Show form 2 on Windows Form 1 Load

Am a newbie when it come to C# Programming. Here's my trouble:
I want to Show a new Form 2 and Hide Form 1 on the Windows Form 1 Load.
Here's my current codes;
private void Form1_Load(object sender, EventArgs e)
{
var Form2 = new Form2();
Form2.Show();
this.Hide();
}
My en-counted Error with the current Code:
When Form 1 load its loading Form 2 but it's not hiding itself. this.Hide Statement not working, I've try this.Close but this will Close the entire software as it's closing the main form.
Can anyone kindly help me with this error.
The Error i thought is that you are showing the form2 before hiding the previous form.
private void Form1_Load(object sender, EventArgs e)
{
var Form2 = new Form2();
form1.Visible=false;
Form2.Show();
}
You can also make form2 as modal by using show dailog method() by which focus is given to the form2 and form1 becomes inactive though it will be shown.
modal and modeless forms https://msdn.microsoft.com/en-IN/library/aa984358%28v=vs.71%29.aspx
Here's how I manage to make this work.
New Codes:
Form 1
private void Form1_Load(object sender, EventArgs e)
{
var Form2 = new Form2();
Form2.Show();
}
private void Timer_Tick(object sender, EventArgs e)
{
if (Properties.Settings.Default.Status == "Form2Visible")
{
this.Hide();
}
}
Explanation:
On the Windows Form 1 Load am showing the the Form 2, then using a timer to verify a Properties.Settings Value. If the Properties.Settings = Form2Visible, Form 1 will Hide. Once am done on Form 2 I simply need to change the Properties.Settings to something else and stop the Timer on Form 1.
If their is a simplest way let me know.
You can use Visible property to hide your form.
private void Form1_Load(object sender, EventArgs e)
{
var Form2 = new Form2();
Form2.Show();
this.Visible=false;
}

Closing multiple windows form with single click

I want to close two forms at the same time. I have one main form that starts with program. when user click button, the main form will hide and other form will pop up. on the second form if user click "back to main " button, it should hide second form and show main form. But the problem is if user tries to close the second form it should close the main form as well. How can i close the main form as well
I would just use the Application.Exit() for what is requested by this thread.
Application.Exit();
UPDATE: corrected
I had said this will not call the form closing events but in documentation it does actually call it here is a link to the documentation
http://msdn.microsoft.com/en-us/library/ms157894(v=vs.110).aspx
It was better if you specified what codes you wrote for going back to main form, so I could help you by changing your codes. But now because I don't know how you did it, I have to write codes for both of those tasks.
It can be possible using a Boolean variable to do what you want. Follow bellow codes:
public partial class MainForm : Form
{
//"Click" event of the button that should opens the second form:
private void goToSecondForm_Click(object sender, EventArgs e)
{
Form2 f2 = new Form2(); //Or you can write it out of this method.
this.Hide(); //Hides the main form.
f2.ShowDialog(); // Shows the second form.
this.Show(); // Shows the main form again, after closing the second form using your own button.
}
}
public partial class Form2 : Form
{
bool selfClose = false; //False shows that user closed the second form by default button and true shows that user closed it by your own button.
//"Click" event of the button that should closes just the second form and returns user to the main form:
private void ownCloseButton_Click(object sender, EventArgs e)
{
selfClose = true; //Means user clicked on your own button.
this.Close(); //So the program closes the second form and runs f2_FormClosed method, but because selfClose became true here, happened nothing there and program will go back to goToSecondForm_Click method in the main form and will run this.Show() .
}
//"FormClosed" event of the second form :
//Whether user clicked on your own button or on the default one, this method will run.
private void f2_FormClosed(object sender, FormClosedEventArgs e)
{
if (!selfClose) //It means user didn't click on your own button and both of forms must be closed .
Application.Exit(); //So the program closes all of forms (actually closes the program) and couldn't access to any other commands (including this.Show() in goToSecondForm_Click method).
}
}
As others have said, you need to somehow call .Close() on the main form when your child form is closed. However, as you've pointed out, you don't have a reference to the main form automatically in your child form! That leaves you with a few options.
1. Exit the application immediately.
This is done by calling Application.Exit(); in your child form's "back to main" button's click event handler. It will immediately close all forms, which might simply be what you want.
// .. ChildForm code ..
void OnBackToMainClicked(object sender, EventArgs e)
{
Application.Exit();
}
2. Pass a reference to the main form to the child form.
This is probably the most common way to solve this problem in general. When you create your child form in your main form, you'll need to pass a reference as follows:
// .. MainForm code ..
void OnGoToChildForm(object sender, EventArgs e)
{
var childForm = new ChildForm(this);
childForm.Show();
}
// .. ChildForm code ..
private MainForm mainForm; // This is where the child form will keep a reference to
// the main form that you can use later
public ChildForm(MainForm mainForm)
{
// This is the child form's constructor that we called above,
// and it's where we'll save the reference to the main form
this.mainForm = mainForm;
}
// This also needs to be the event handler for the close event
void OnBackToMainClicked(object sender, EventArgs e)
{
this.Close();
mainForm.Close();
}
3. Add an event handler on the child form's FormClosed event. This is a safe way to solve the problem if you are concerned about keeping your main application logic under the control of the main form. It's similar to the solution suggested by Lamloumi above, but it's all done in the main form's code.
// .. MainForm code ..
void OnGoToChildForm(object sender, EventArgs e)
{
var childForm = new ChildForm(this);
childForm.FormClosed += new FormClosedEventHandler(SecondForm_FormClosed);
childForm.Show();
}
void SecondForm_FormClosed(object sender, EventArgs e)
{
// Perform any final cleanup logic here.
this.Close();
}
Form1 _FirstForm = New Form1();
Form2 _SecondForm = New Form2();
MainForm _MainForm = new MainForm();
_FirstForm.Close();
_SecondForm.Close();
_MainForm.Show();
Normally , in the Home form you have some ting like this :
SecondForm second= new SecondForm ();
second.Show();
this.Hide();
In the SecondForm you must ovveride the event of closure like this :
public class SecondForm :Form{
public SecondForm()
{
InitializeComponent();
this.FormClosed += new FormClosedEventHandler(SecondForm_FormClosed);
}
void SecondForm_FormClosed(object sender, FormClosedEventArgs e)
{
Application.Exit();
}
}
To be sure that your application is closed after you close the form. because the Home from is still active and hidden if you don't.
use this in Form2
private void button1_Click(object sender, EventArgs e)
{
Form1.FromHandle(this.Handle);
}
There Handle are the same now ;
hope this work.

Hiding a form, switch to a second form, close second form and unhide first form

I've looked at all the suggested answers and nothing seems to fit what I'm looking for. I want to call a second form from my main form, hide my main form while the second form is active, and then unhide the main form when the second form closes. Basically I want to "toggle" between the two forms.
So far I have:
In my main form:
private void countClick(object sender, EventArgs e)
{
this.Hide();
subForm myNewForm = new subForm();
myNewForm.ShowDialog();
}
and in my second form I have:
private void totalClick(object sender, EventArgs e)
{
this.Close();
}
How do I get the main form to show?
ShowDialog opens your secondary Form as Modal Dialog, meaning that the MainForm's code execution will stop at that point and your secondary Form will have the focus. so all that you need to do is put a this.Show after your ShowDialog call.
From above link:
You can use this method to display a modal dialog box in your application. When this method is called, the code following it is not executed until after the dialog box is closed.
private void countClick(object sender, EventArgs e)
{
this.Hide();
subForm myNewForm = new subForm();
myNewForm.ShowDialog();
this.Show();
}
Let's say in Form1 you click a Button to show Form2
Form2 frm2 = new Form2();
frm2.Activated += new EventHandler(frm2_Activated); // Handler when the form is activated
frm2.FormClosed += new FormClosedEventHandler(frm2_FormClosed); // Hander when the form is closed
frm2.Show();
Now, this one is when the Form2 is shown or is Activated you hide the calling form, in this case the Form1
private void frm2_Activated(object sender, EventArgs e)
{
this.Hide(); // Hides Form1 but it is till in Memory
}
Then when Form2 is Closed it will Unhide Form1.
private void frm2_FormClosed(object sender, FormClosedEventArgs e)
{
this.Show(); // Unhide Form1
}
This is difficult to do correctly. The issue is that you must avoid having no window at all that can get the focus. The Windows window manager will be forced to find another window to give the focus to. That will be a window of another application. Your window will disappear behind it.
That's already the case in your existing code snippet, you are hiding your main window before showing the dialog. That usually turns out okay, except when the dialog is slow to create. It will definitely happen when the dialog is closed.
So what you need to do is hide your window after you display the dialog and show it again before the dialog closes. That requires tricks. They look like this:
private void countClick(object sender, EventArgs e)
{
this.BeginInvoke(new Action(() => this.Hide()));
using (var dlg = new subForm()) {
dlg.FormClosing += (s, fcea) => { if (!fcea.Cancel) this.Show(); };
if (dlg.ShowDialog() == DialogResult.OK) {
// etc...
}
}
}
The BeginInvoke() call is a trick to get code to run after the ShowDialog() method runs. Thus ensuring your window is hidden after the dialog window is shown. The FormClosing event of the dialog is used to get the window to be visible again just before the dialog closes.
You need to find some way to pass a reference to the main form to the second form click event handler.
You can do this either by setting the form as a member variable of the second form class or pass it via the event arguments.
If you are working in the same namespace, you have the context, using mainform or the name you gave the "main form", try:
mainform.show();

Close All application click X Winform

I'm trying to change the names of the datagrid and labels in Form2 from Form1 based on the selection.
private void button1_Click_1(object sender, EventArgs e)
{
this.Hide();
Form2 frm = new Form2();
frm.Show();
}
private void button2_Click(object sender, EventArgs e)
{
Form2 frm = new Form2();
frm.dataGridView1.Columns["FirstName"].HeaderText = "Prenom";
frm.dataGridView1.Columns["LastName"].HeaderText = "Nom";
this.Hide();
frm.Show();
}
The above approach is working fine for me but I have a problem. When I click on X in the second/Form 2 it's just closing the Form2 not the Form1. How can close all the application when i click on the X.
Is there any better way of doing this??? The reason why i'm not using I'm using Telerik and I don't find any option to add resource file in that. Please correct me if i'm wrong. Thank you.
You simply need to attach an event handler to the Closed event of the newly created form so that it closes the main form when it's closed:
private void button1_Click_1(object sender, EventArgs e)
{
this.Hide();
Form2 frm = new Form2();
frm.FormClosed += (_, args) => this.Close(); //Added this method
frm.Show();
}
Add that same method to the other click handler as well.
The easiest way to close an application is to call the static method: Application.Exit
Another method if you only want to close one single form would be to add a handler for the FormClosing event and close the main form there.

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