Passing a Form reference

I have three forms: Form1, Form2 and Form3. I want to be able to pass a reference to either Form2 or Form3 so that Form1 will invoke the appropriate one when a button is clicked. So I set up a Form property in Form1:

Code:

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private System.Windows.Forms.Form m_frmAddEdit;
...
public System.Windows.Forms.Form AddEditForm
{
          get { return m_frmAddEdit;  }
          set { m_frmAddEdit = value; }
}

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I've passed other object references in this manner (specifically, an OdbcConnection), so I figured this would be fine.

Unfortunately, when I try to pass a Form reference:

Code:

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Form1 frm = new Form1();
frm.AddEditForm = Form2;

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The compiler complains that:

Quote:

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'Form2' denotes a 'class' where a 'variable' was expected

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and

Quote:

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'Form1.m_frmAddEdit' denotes a 'field' where a 'class' was expected

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This latter error is in reference to the following line in Form1:

Code:

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m_frmAddEdit frmToCall = new m_frmAddEdit();

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What am I doing wrong here? I don't understand why C# expects the property I declared as a Form to be a 'variable'.

Do I need to be looking at some way to do this with Delegates instead? (I'd like to keep the calling/invoking logic inside Form1.)

Okay, I see what my problem is. But now the question becomes:

How do I pass a reference to a class (not an object)?

Okay, (in case anybody cares) I've got mostly what I want by using the GetType() method:

Code:

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if (m_frmAddEdit.GetType() == (new Form2()).GetType())

 - or -

if (m_frmAddEdit.GetType().Equals((new Form2()).GetType()))

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This will work, but it gets messy if there are a lot of possible forms and a lot of methods and properties I need to call - which winds up being a lot of (Form2) casting.

Ideally, I'd like to be able to do something like

Code:

---

if (...GetType(Form2)...) {
  frm = (Form2)m_frmAddEdit;
}
...
frm.CallMethod();

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but scope rules keep me from making this work. I can't declare frm outside of the if statement (as scope rules would require) because I don't yet know what Type it is. And I can't declare it inside the if because then it won't be available outside.

I seem to remember some languages having some kind of mechanism for making local variables available outside the blocks they were declared in. I don't see anything like this for C#, though. Is there any such thing?

not sure if this is what you wanna do, here's how to access controls between forms...
in Form1:

Code:

---

private void button1_Click(object sender, System.EventArgs e)
{
Form2 frm=new Form2();
this.AddOwnedForm(frm);// add this line when opening form2.
frm.Show();
}

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in Form2:

Code:

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private void button1_Click(object sender, System.EventArgs e)
{
Form1 frmMain=(Form1)this.Owner;
frmMain.textBox1.AppendText("some stuff");
}

---

Quote:

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Originally posted by dynamic_sysop

Code:

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private void button1_Click(object sender, System.EventArgs e)
{
Form1 frmMain=(Form1)this.Owner;
frmMain.textBox1.AppendText("some stuff");
}

---

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My problem goes beyond this. Given your code sample above, how would you handle the fact that, within button1_Click(), you don't know that Form1 is the form you need to cast to?

What if the form could be any of Form3, Form4, Form5, Form6, Form7, etc. - dynamically chosen at runtime?