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I have a problem while i am self learning C#. Here it is.
On a windows form application i have 2 froms(Form1 and Form2) . I show the Form2 to open an Excel file and read some data and then upon clicking "ok" on Form2 i need to execute a function on form1 and form2 can be closed(Of course i do this by this.close()).
Kindly let me know how i can call functions in form1 from form2.
I need to do this because form1 has data which needs to be worked upon.
Updated 25-Jul-21 11:41am
Steven.Pinto2000 30-May-11 3:23am
Can you show a demo code ?

This is a popular question about form collaboration. The most robust way is implementation of appropriate interface by the form class.

For more details, please see my past answer:
How to copy all the items between listboxes in two forms[^]. See also other suggestions and discussion.


You can also use delegate:

In Form2:

public delegate void methodHandler();
public methodHandler OnRunMethod;

In OK Click event:
if (OnRunMethod != null)

private void OK_Click(object sender, RoutedEventArgs e)
    if (OnRunMethod != null)

In Form1 (where you open Form2):

Form2 form2 = new Form2();
form2.OnRunMethod += new methodHandler(MyMethod);
form2.Show() // or ShowDialog()

and in Form1:
private void MyMethod()
    //Do somethings

I think it's a perfect way because it can be called from Form2 and you can use both of Show() or ShowDialog().

Good luck.
On Form1's event where you open Form2, follow this -

1. Create object for form
Form2 f = new Form2();
2. Use f.ShowDialog() to open the form
3. Do what you do in form2
4. Code the other stuff after f.ShowDialog() which would run after form2 is closed.
asjadazeez 30-May-11 3:28am
Nice and simple solution. I just overlooked "showdialog" Thanks man !
Prerak Patel 30-May-11 4:11am
You are welcome.
Shahin Khorshidnia 30-May-11 4:54am
+5 It works.
form1 Test= new form1()
asjadazeez 30-May-11 3:30am
Thanks got it.
JustWorking 30-May-11 8:17am
Remember to 5 :)
Make this method public and pass a reference to Form1 to Form2 constructor (custom ShowDialog method/whatever). Calling one form methods from another is not good practice, though. If possible, move it to another place (mediator class, static class or something)
Pass a reference of Form1 into Form2.
Once you need to call Form1, simply call the appropriate Form method (a public method) and then just close Form2.

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