C#

public class Parent
{
    public virtual void FunctionOne()
    {
    }
}
...
public class GreatGrandChild : GrandChild
{
    public override void FunctionOne()
    {
         Console.WriteLine("Called in GreatGrandChild");
         base.FunctionOne();
    }
}

Pdeveloper wrote:

Windows ? or Web based ?.

1. No, sounds like a bad idea.
2. I would say yes it's a bad thing, but I have never tested it to see the effect on resources/performance.
3. Certainly, they do enough bad things as it is.

BillWoodruff wrote:

And, I believe the idea of using a TabControl to implement a multi-document work-space is a good one.

BillWoodruff wrote:

A Form is a "heavy-weight" object; using "lighter-weight" objects.

BillWoodruff wrote:

If I consider what, if any, advantages there might be to using a Form within a Form, I find it hard to come up with anything tangible.

BillWoodruff wrote:

is it something you do yourself in your own practice (in situations you are not using MDI) ?

BillWoodruff wrote:

is it a very "bad thing" in terms of consuming resources (like memory) compared other possible containers ? Does it diminish performance ?

BillWoodruff wrote:

3. do you think it is a mistake for beginning programmers to use Forms inside Forms ?

BillWoodruff wrote:

Bias: I find MDI apps butt-ugly.

Bastard Programmer from Hell
If you can't read my code, try converting it here[^]

BillWoodruff wrote:

"One can set a new parent, and could choose to set the apps' parent to a button,"

BillWoodruff wrote:

give an example of why you would implement this, and how you would use this type of relationship ?

BillWoodruff wrote:

I also fail to see how using a Form within a Form inherently promotes "Encapsulation and re-use" in a way that a Form that is not contained in another Form does not.

BillWoodruff wrote:

Using a Form within a Form in WinForms means you sacrifice the ability to do design-time layout of the Form's position in its containing Form.

BillWoodruff wrote:

Another thing a Form in a Form offers is ... if it has a TitleBar ... instant movability, but WinForms provides no "easy" way to constrain a contained Form's location in its Parent Form.

BillWoodruff wrote:

he ad hominem argument that it's a "skin deep" point-of-view on my part, I assert that MDI architecture has the effect of diminished productivity compared to other multi-window management strategies, and I do not believe there's any inherent "efficiency" in MDI compared to managing multi-documents with a Tabbed UI (TDI).

BillWoodruff wrote:

the "kicker" being that if you regard a tabbed multi-window management application as a form of MDI: well, then MDI is going strong.

BillWoodruff wrote:

I suspect one thing you and I could completely agree on would be the idea that one cannot make any absolute rule about application design

Bastard Programmer from Hell
If you can't read my code, try converting it here[^]

joost.versteegen wrote:

Why not use a TabControl and open a new TabPage i.s.o. a new Form in a Form?

private void btnVisibleControl_Click(object sender, EventArgs e)
{
    secondForm.Visible = ! secondForm.Visible;
}

private void secondForm_FormClosing(object sender, FormClosingEventArgs e)
{
    this.Hide();
    e.Cancel = true;
}

private secondForm f2;

private string strClose = "Close Second Form";

private string strOpen = "Open Second Form";

private void FormTemplate_Load(object sender, EventArgs e)
{
    f2 = new secondForm();

    // by assigning 'secondForm's Closing EventHandler here:
    // we can synchronize the Button Text easily since the
    // the EventHandler will have access to the Button
    f2.FormClosing += f2_FormClosing;

    btnVisibleControl.Text = strOpen;
}

// prevent the instance of 'secondForm from actually closing
private void f2_FormClosing(object sender, FormClosingEventArgs e)
{
    f2.Hide();

    // update the Button Text
    btnVisibleControl.Text = strOpen;

    e.Cancel = true;
}

// change the Button Text so the end-user sees
// what pressing the Button will do
private void button1_Click(object sender, EventArgs e)
{
    if (f2.Visible)
    {
        btnVisibleControl.Text = strOpen;
    }
    else
    {
        btnVisibleControl.Text = strClose;
    }

    // or you can use this to make the code (above) simpler:
    // btnVisibleControl.Text = (f2.Visible) ? strOpen : strClose;

    f2.Visible = ! f2.Visible;
}