Inhetited form event order

[Sergey Atun]

Hi,
I inherited form and I writed it's load event:

public class frmBase: System.Windows.Forms.Form
{
....
private void frmBase_Load(object sender, System.EventArgs e)
{
MessageBox.Show("this event must run after derived class' (frmInherited)
load event");
}
....
}

When I created new form by inherited this, I writed it's load event too.

public class frmInherited : frmBase
{
{
....
private void frmInherited_Load(object sender, System.EventArgs e)
{
MessageBox.Show("this event must run before parent class' (frmBase) load
event");
}
....
}

How can I run firstly frmInherited_Load event and after that run
frmBase_Load event.

 

[=?ISO-8859-2?Q?Marcin_Grz=EAbski?=]

Hi Sergey,

I recommend you to override "OnLoad(...)" methods.
You'll get access to order of "OnLoad(...)" call.

e.g.

// in frmBase
protected override void OnLoad(EventArgs e) {
// Load event first
base.OnLoad(e);

// your handler's method next
frmBase_Load(this, e);
}

// in frmInherited
protected override void OnLoad(EventArgs e) {
// OnLoad(...) in frmBase first
base.OnLoad(e);

// your handler's method next
frmInherited_Load(this, e);
}

Regards

Marcin

 

[Guest]

ups!

// in frmInherited
protected override void OnLoad(EventArgs e) {
// your handler's method next
frmInherited_Load(this, e);

// OnLoad(...) in frmBase first
base.OnLoad(e);
}

;-)

Marcin

 

[Robert Jordan]

Hi Sergey,

Hi,
I inherited form and I writed it's load event:

public class frmBase: System.Windows.Forms.Form
{
...
private void frmBase_Load(object sender, System.EventArgs e)
{
MessageBox.Show("this event must run after derived class' (frmInherited)
load event");
}
...
}

When I created new form by inherited this, I writed it's load event too.

public class frmInherited : frmBase
{
{
...
private void frmInherited_Load(object sender, System.EventArgs e)
{
MessageBox.Show("this event must run before parent class' (frmBase) load
event");
}
...
}

How can I run firstly frmInherited_Load event and after that run
frmBase_Load event.

You cannot. The calling order of event handlers is undefined.

However, you're probably looking for that:

public class frmBase: System.Windows.Forms.Form
{
protected override OnLoad(EventArgs e) {
base.OnLoad(e);
// your code
}
}

public class frmInherited : frmBase
{
protected override OnLoad(EventArgs e) {
base.OnLoad(e);
// your code
}
}

the "your code" blocks are executed in the expected order.

bye
Rob

 

[Robert Jordan]

Hi Marcin,

Hi Sergey,

I recommend you to override "OnLoad(...)" methods.
You'll get access to order of "OnLoad(...)" call.

e.g.

// in frmBase
protected override void OnLoad(EventArgs e) {
// Load event first
base.OnLoad(e);

// your handler's method next
frmBase_Load(this, e);

this is wrong. the event handler was already called by base.OnLoad()!

bye
Rob

 

[Guest]

Hi Robert,

Hi Marcin,



this is wrong. the event handler was already called by base.OnLoad()!

Ok, my fault!
Only if you add this method as an "EventHandler" of "Load" event.

I forgot to tell that "frmBase_Load" (and "frmInherited_Load") should
be removed from event handling... and put into "OnLoad(...)" body
(with unchanged declaration) as a methods.

So, they can stay as a common methods, not as an event hadlers.

Marcin