Question

I have a winform application that goes with name myForm. Within this form I open another form:

    private OtherForm otherForm; //this is a field

    private OpenOtherForm()
    {
       if (otherForm == null)
       {
          otherForm = new OtherForm();
          otherForm.FormClosing += delegate { MessageBox.Show("OtherForm will be closed"); otherForm = null};
       }

       MessageBox.Show("Form is already active!");
    }

This works fine. But I have some methods in the second form as well. I would like to try capturing theire call.

For example if OtherForm.DoSomething() is called within the second form, I want a message box to show thi.

I tried to assign OtherForm.DoSomething() += delegate { /* mesagebox */}; But this does not compile

Answer 1

If you want to respond to a call in another form you could add an event to the other form and raise it in the method you are trying to respond to.

class Form1: Form
{
    public void Button1_Click(object sender, EventArgs e)
    {
        var form2 = new Form2();
        form2.SomeMethodCalled += Form2_SomeMethodCalled;
    }

    public void Form2_SomeMethodCalled(object sender, EventArgs e)
    {
        // method in form2 called
    }
}


class Form2 : Form
{
    public event EventHandler SomeMethodCalled;

    public void SomeMethod()
    {
        OnSomeMethodCalled();
        // .....
    }

    private void OnSomeMethodCalled()
    {
        var s = SomeMethodCalled;
        if(s != null)
        {
            s(this, EventArgs.Empty);
        }
    }
}