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How to close a form and come back to mainform

My question seems very easy but it's actually quite tricky. I search a lot on here and I dont find anything conclusive.
I have a mainform which need to be constantly open. I have a button which call a form2, I do some action on it, then call a form3 which let the user choose some item then close it and come back to mainform. The tricky part is i need to pass data from f3 to f1.
My problem is, on the second form I have a next & cancel buttons (and a close button) . Next button hide f2, form1 "come back" & call the form3. Why not call directly the form3? because I need to pass data from form3 to form1 so i Need to call form3 from form1.
So i want Cancelbutton (and closing button) to come back to form1 without calling form3. I am not sure to be understood so here's my code
public partial class Form1 : Form
{
private void bouya_Click(object sender, EventArgs e)
{
Form2 form2 = new Form2();
form2.ShowDialog();
Form3 form3 = new Form3(); //it opens when form2 closes!!!
form3.ShowDialog();
string data1 = form3.label2.Text; //the data i need, without calling form3 from here i can't pass data !!!
//do some action with data1
}
}
form2 is very simple
public partial class Form2 : Form
{
private void Next_Click(object sender, EventArgs e)
{ this.Hide(); }
private void Cancel_Click(object sender, EventArgs e)
{//i just want here to cancel winform3 to be called}
private void Form2_Closing(object sender, System.ComponentModel.CancelEventArgs e)
{ // Actually this command does'nt work at all i tried
//to put a messagebox.Show("bla") nothing happens but i would like to do the same}
}
And form3 I select an item from a list to be send to form1
public partial class Form3 : Form
{
private void button1_Click(object sender, EventArgs e)
{
foreach (Object obj in listBox1.SelectedItems)
{
label2.Text = obj.ToString();
this.Hide();
}
}
}
Ok for some of you my problem would seem useless and i complicated my code for nothing but i really need these form. (and i need to open form3 from form1 to send data 3 to 1)
Forget about *Form1 form1 = new Form1(); it calls a new form1 and i don't want it !

You actually do not need to call form3 from form1 just to pass a value. If I understand you correctly, the desired flow should be like this
form1
opens
form2
opens
form3
|
| value
|
form1 <---+
So form1 opens form2 which opens form3 and the value from form3 should be passed back to form1, right?
What I'd do is declare a property ValuePickedInForm3 or whatever in form2 and get this in form1 when form2 closes.
Example
This pseudo-code is in the form2 class
public string ValueFromForm3
{
get;
private set;
}
public void ShowForm3()
{
using (Form3 f3 = new Form3())
{
if (f3.ShowDialog(this) == DialogResult.OK)
ValueFromForm3 = f3.TheValueYouNeed;
}
}
This pseudo-code goes into the form1 class:
public void ShowForm2()
{
using (Form2 f2 = new Form2())
{
if (f2.ShowDialog(this) == DialogResult.OK)
DoSomethingWith(f2.ValueFromForm3);
}
}

Prevent multiple instances winform [duplicate]

There is two Forms in my project : Form1 and Form2.
There is a button in Form1, and what I want to do is closing Form1 and showing Form2 when that button clicked.
First, I tried
Form2 frm = new Form2();
frm.Show();
this.Close();
but as Form1 was closed, Form2 also got closed.
Next, I tried
Form2 frm = new Form2();
frm.Show();
this.Hide();
but there is a disadvantage that the application does not exit when the Form2 is closed.So, I had to put in additional sources in form_FormClosing section of Form2.
Hmm.... I wonder whether this is the right way....So, what is the proper way of handling this problem?

The auto-generated code in Program.cs was written to terminate the application when the startup window is closed. You'll need to tweak it so it only terminates when there are no more windows left. Like this:
[STAThread]
static void Main() {
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
var main = new Form1();
main.FormClosed += new FormClosedEventHandler(FormClosed);
main.Show();
Application.Run();
}
static void FormClosed(object sender, FormClosedEventArgs e) {
((Form)sender).FormClosed -= FormClosed;
if (Application.OpenForms.Count == 0) Application.ExitThread();
else Application.OpenForms[0].FormClosed += FormClosed;
}

By default, the first form controls the lifetime of a Windows Forms application. If you want several independent windows forms your application context should be a separate context from the forms.
public class MyContext : ApplicationContext
{
private List<Form> forms;
private static MyContext context = new MyContext();
private MyContext()
{
forms = new List<Form>();
ShowForm1();
}
public static void ShowForm1()
{
Form form1 = new Form1();
context.AddForm(form1);
form1.Show();
}
private void AddForm(Form f)
{
f.Closed += FormClosed;
forms.Add(f);
}
private void FormClosed(object sender, EventArgs e)
{
Form f = sender as Form;
if (form != null)
forms.Remove(f);
if (forms.Count == 0)
Application.Exit();
}
}
To use the context, pass it to Application.Run (instead of the form). If you want to create another Form1, call MyContext.ShowForm1() etc.
public class Program
{
public void Main()
{
Application.Run(new MyContext());
}
}

You can take this way:
form2 f2=new form2()
this.Hide();
f2.Show();
Hope it was helpful.

Write that into your method which is executed while FormClosing event occure.
private void Form1_Closing(object sender, System.ComponentModel.CancelEventArgs e)
{
// Display a MsgBox asking the user if he is sure to close
if(MessageBox.Show("Are you sure you want to close?", "My Application", MessageBoxButtons.YesNo)
== DialogResult.Yes)
{
// Cancel the Closing event from closing the form.
e.Cancel = false;
// e.Cancel = true would close the window
}
}

Why do my C# Form closed when displayed?

i have 2 forms, those are form1.cs and form2.cs
on the form1, it has button1, which will call form2 to show
here's the button1 code
private void button1_Click(Object sender, EventArgs e )
{
form2 form = new form2();
form2.show(); // to call form2
this.dispose(); //to dispose form1
}
and then form2 showed, and it closed suddenly. anyone know how to solve this ?

When you close your main form with this.dispose() you are terminating the program causing form2 to be disposed also because you are diposing the reference to form2. You would be better off passing a reference to your form1 to form2 and using this.Hide() instead.
You can try something like this:
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
Form2 form = new Form2();
form.setParent(this);
form.Show();
this.Hide();
}
}
And in form2 to go back to form1
public partial class Form2 : Form
{
Form parentForm;
public Form2()
{
InitializeComponent();
}
public void setParent(Form value)
{
parentForm = value;
}
private void button1_Click(object sender, EventArgs e)
{
parentForm.Show();
this.Close();
}
}

private void button1_Click(Object sender, EventArgs e )
{
form2 form = new form2();
form2.show(); // to call form2
this.hide(); //to hide form1
}

if form1 is program starter then application will close . Hence instead
this.dispose();
U just write
this.hide();

Show() does not wait for form2 to close before continuing to the next command (dispose).
This will end up in closing form2 because it's probably running on a background thread.
Use ShowDialog to hold the execution of Dispose until the second form closes.
Also, you can set the second form to run on a foreground thread. This way the second form will not be dependent on the life of the first.

You can either use this.Hide() which should hide your current form or use a thread to open the new form.
Example: C# open a new form, and close a form...

Open Form2 from Form1, close Form1 from Form2

Now, I have two forms, called form1 and form2, in the form1 there's a button, when I click it, then open the form2
Question: in the form2, I want to create a button when I click it, the form2 close and the form1 close. How to do?this

Form1:
private void button1_Click(object sender, EventArgs e)
{
Form2 frm = new Form2(this);
frm.Show();
}
Form2:
public partial class Form2 : Form
{
Form opener;
public Form2(Form parentForm)
{
InitializeComponent();
opener = parentForm;
}
private void button1_Click(object sender, EventArgs e)
{
opener.Close();
this.Close();
}
}

This works:
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Me.Hide()
Form2.Show()

Your question is vague but you could use ShowDialog to display form 2. Then when you close form 2, pass a DialogResult object back to let the user know how the form was closed - if the user clicked the button, then close form 1 as well.

on the form2.buttonclick put
this.close();
form1 should have object of form2.
you need to subscribe Closing event of form2.
and in closing method put
this.close();

if you just want to close form1 from form2 without closing form2 as well in the process, as the title suggests, then you could pass a reference to form 1 along to form 2 when you create it and use that to close form 1
for example you could add a
public class Form2 : Form
{
Form2(Form1 parentForm):base()
{
this.parentForm = parentForm;
}
Form1 parentForm;
.....
}
field and constructor to Form2
if you want to first close form2 and then form1 as the text of the question suggests, I'd go with Justins answer of returning an appropriate result to form1 on upon closing form2

I did this once for my project, to close one application and open another application.
System.Threading.Thread newThread;
Form1 frmNewForm = new Form1;
newThread = new System.Threading.Thread(new System.Threading.ThreadStart(frmNewFormThread));
this.Close();
newThread.SetApartmentState(System.Threading.ApartmentState.STA);
newThread.Start();
And add the following Method. Your newThread.Start will call this method.
public void frmNewFormThread)()
{
Application.Run(frmNewForm);
}

//program to form1 to form2
private void button1_Click(object sender, EventArgs e)
{
//MessageBox.Show("Welcome Admin");
Form2 frm = new Form2();
frm.Show();
this.Hide();
}

private void button1_Click(object sender, EventArgs e)
{
Form2 m = new Form2();
m.Show();
this.Visible = false;
}

I would like to control Form1 from Form2

So I want basically the user to login in first in order to use the other form. However, my dilemma is that the login box is in Form2, and the main form is Form1.
if ((struseremail.Equals(username)) && (strpasswd.Equals(password)))
{
MessageBox.Show("Logged in");
form1.Visible = true;
form1.WindowState = FormWindowState.Maximized;
}
else
{
MessageBox.Show("Wow, how did you screw this one up?");
}
However, Form1 doesn't become visible, (since I launch it as visble = false) after they log in. Can someone help?
EDIT:
Brilliant response, but my problem is still here. I basically want to load Form2 First, (which is easy I run Form1 and set it to hide) But when Form2 is closed, I want Form1 to be closed as well.
private void Form2_FormClosing(Object sender, FormClosingEventArgs e)
{
Form1 form1 = new Form1();
form1.Close();
MessageBox.Show("Closing");
}
this doesn't seem to work...

You will need to pass the reference of one form to another, so that it can be used in the other form. Here I've given an example of how two different forms can communicate with each other. This example modifies the text of a Label in one form from another form.
Download Link for Sample Project
//Your Form1
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
Form2 frm = new Form2(this);
frm.Show();
}
public string LabelText
{
get { return Lbl.Text; }
set { Lbl.Text = value; }
}
}
//Your Form2
public partial class Form2 : Form
{
public Form2()
{
InitializeComponent();
}
private Form1 mainForm = null;
public Form2(Form callingForm)
{
mainForm = callingForm as Form1;
InitializeComponent();
}
private void Form2_Load(object sender, EventArgs e)
{
}
private void button1_Click(object sender, EventArgs e)
{
this.mainForm.LabelText = txtMessage.Text;
}
//Added later, closing Form1 when Form2 is closed.
private void Form2_FormClosed(object sender, FormClosedEventArgs e)
{
mainForm.Close();
}
}
(source: ruchitsurati.net)
(source: ruchitsurati.net)

When you log in and do Form1.visible = true; have you also tried Form1.Show(); that should show form2
However, Personally, I would prefer setting the application to run form2 directly in the program.cs file.
static void Main()
{
Application.Run(new Form2());
}
then when user successfully logs in, do
form1.Show();
this.Hide(); // this part is up to you
mind you, in form2, when / after you instantiate form1, you might want to also add this :
newform1.FormClosed += delegate(System.Object o, FormClosedEventArgs earg)
{ this.Close(); };
this closes form2 when form1 is closed
better yet do form1.Show() in a new thread, and then this.Close(); for form2. this removes the need of adding to the form2's FormClosed event: you can thus close form2 immediately after starting form1 in a new thread. But working with threads might get a little complicated.
EDIT:
form2 is form1's parent. if form2 is your main application form, closing it closes your program (generally). Thus you either want to just hide and disable form2, and close it only after form1 is closed, or start form1 in a new thread. Your edit pretty much opens form1, then immediately closes it.